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Restricted Distribution IOC/ITSU-XVIII/15 Paris, 28 September 2001 English only INTERGOVERNMENTAL OCEANOGRAPHIC COMMISSION (of UNESCO) Eighteenth Session of the International Co-ordination Group for the Tsunami Warning System in the Pacific (ICG/ITSU-XVIII) 8-11 October 2001, Cartagena, Colombia DRAFT TSUNAMI PRESS KIT (Textual Part) The ICG/ITSU at its Seventeenth Session “requested the ITIC Director to take the lead in developing a Press Kit with a video section. To assist him in implementing this task, a Working Group was established with experts from Canada and Chile”. It was agreed that the draft of the Kit be ready for the 2001 ITSU Officers Meeting. Following this recommendation, the Director ITIC provided the first draft of the Kit. The Officers requested the contents and format of the draft to be considerably changed and invited IOC to develop a new version of the Kit. In compliance with this request, the draft of the textual part of the Press Kit has been developed based on the list of contents approved by the Officers. It is presented in this document. The ICG/ITSU will be invited to comment on the content, taking into account that the Kit users will not only be the mass media but also decision-makers, teachers, scientists, other professionals and the public in large. The ICG/ITSU will provide guidance on further steps required for the finalization and publication of the Kit in an attractive format and on the resources needed. IOC/ITSU-XVIII/15 page 1 PREFACE Tsunami disasters pose a major threat to the coastal populations of the Pacific and other world oceans and seas. They have been responsible for the loss of thousands of lives and great damage to property. Although understanding of the tsunami phenomenon has dramatically increased in the past four decades and early warning systems have been established, these advances have been partially offset by population growth and extensive development of coastal zones. Therefore, the tsunami risk and vulnerability of people living in coastal areas will continue to increase in the future. The present Press Kit is provided as an educational tool on the tsunami hazard. It answers basic questions and outlines the Intergovernmental Oceanographic Commission's (IOC) Tsunami Programme in managing and coordinating international efforts in mitigating the effects of this terrible natural disaster. The Press Kit is provided in loose-leaf form to permit continuous updates. IOC/ITSU-XVIII/15 page 2 MESSAGE FROM THE IOC EXECUTIVE SECRETARY Tsunamis are considered the sixth largest natural hazard, the first five being, in order: storm surges, earthquakes, flash floods, cyclones and tornadoes. Tsunamis do not occur regularly or frequently. There have been no Pacific Ocean-wide tsunamis since March 1964 but there have been local tsunamis in the Pacific, which killed, on the average, about a thousand people a year. For a natural hazard that occurs infrequently, there is always a danger that the public and the people concerned with the warning may become complacent and allow the warning system to get out- dated and ineffective. We have to guard against this. Since 1964, IOC is taking on the international responsibility in co-ordinating the efforts of the Member States in operating the Tsunami Warning System in the Pacific. For about 40 years, the Commission, through it’s International Co-ordinating Group for the Tsunami Warning System (ICG/ITSU) in the Pacific, has organized and co-ordinated efforts which have assured the timely dissemination of tsunami warnings throughout the Pacific, with the direct results in saving lives and protecting property. The IOC Tsunami Programme is one of the most successful international scientific and humanitarian efforts in disaster reduction, fully responding to the culture of disaster prevention emphasized by the Director-General of the UN during the International Decade of Natural Disaster Reduction, which came to an end in 1999. The success of the programme has been made possible by the co-operation and generous contributions of participating member nations, presently numbering 28 and growing. The Tsunami Programme efforts have been recently expanded to the Indian Ocean, as well as the Caribbean and Mediterranean Seas. Tsunami research, monitoring and mitigation are matters which mankind is bound to view with increasing seriousness. Member States should be equipped to face disasters like tsunamis, to explore factors which trigger such catastrophes and to be able to forecast them in good time and to make the population ready to take preventive measures, so as to minimize their terrible effects through systematic and planned efforts. The present Press Kit is intended to bring about a better understanding of the tsunami hazard and its risk potential. Its scope is to familiarize researchers, decision-makers, emergency managers, practitioners and the general public with the IOC Tsunami Programme, the International Tsunami Warning System, its elements and resources. The Press Kit will help us all to get to thinking as to how well we are prepared and what we need to do to respond effectively to the hazard before and during the course of the event. (Signature) Patricio Bernal Executive Secretary - Intergovernmental Oceanographic Commission UNESCO IOC/ITSU-XVIII/15 page 3 CONTENTS 1. INTERGOVERNMENTAL OCEANOGRAPHIC COMMISSION & ITS TSUNAMI PROGRAMME - GLIMPSE INTO THE PAST. Historical Background The International Coordination Group for the Tsunami Warning System in the Pacific (ICG-ITSU). The International Tsunami Information Centre (ITIC) and its Mandate 2. TSUNAMI - TOP 10 QUESTIONS FREQUENTLY ASKED. What is a tsunami? How do earthquakes generate tsunamis? How do volcanic eruptions generate tsunamis? How do submarine landslides, rock falls and underwater slumps generate tsunamis? Can asteroids, meteorites or man-made explosions cause tsunamis? Where and how frequently are tsunamis generated? How does tsunami energy travel across the ocean and how far can tsunamis waves reach? Why Tsunamis cannot be seen at sea or from the air? What are the factors of destruction from tsunamis? What determines how destructive a tsunami will be near the origin and at a distant shore? What are some of the largest historical tsunamis? The April 1, 1946 Aleutian Tsunami The November 4, 1952 Kamchatka Tsunami The March 9, 1957 Aleutian Tsunami The May 22, 1960 Chilean Tsunami The March 28, 1964 Alaska Tsunami Why are locally generated tsunamis so dangerous? 3. TSUNAMI WARNING SYSTEM - A VIGILANT 24 HOUR WATCH. Membership Organization Programme Management Main Operational Components 4. BASIC FACTS ABOUT THE OPERATION OF THE PACIFIC TSUNAMI WARNING SYSTEM - HOW IT WORKS Watch and Warning Communications Watch Bulletins Tsunami Warning Issuance and Cancellation Testing of Pacific Tsunami Warning Communications Response and Regional Warnings for locally generated tsunamis IOC/ITSU-XVIII/15 page 4 5. RECENT TSUNAMI DISASTERS: SOME FACTS AND FIGURES Nicaragua - 2 September 1992 Indonesia - Flores Island - 12 December 1992 Japan - Okushiri - 12 July 1993 Indonesia - Java - 3 June 1994 Russia - Shikotan Is. - 4 October 1994 Philippines - Mindoro - 15 November 1994 Mexico - Manzanillo - 9 October 1995 Peru - Northern - 21 February 1996 Papua-New Guinea - 17 July 1998 Turkey - Sea of Marmara - 17 August 1999 Vanuatu - 26 November 1999 Peru - Southern - 23 June 2001 6. THREE STEPS IN REDUCING THE IMPACT OF TSUNAMIS Hazard Assessment Warning Preparedness 7. IDNDR - LESSONS LEARNED Historical Perspective UNESCO-IOC Tsunami Programme Contribution to the IDNDR Lessons Learned 8. THE TSUNAMI PROGRAMME IN THE NEW MILLENNIUM - TAMING THE KILLER WAVES Future Mitigation Efforts 9. ADDITIONAL STEPS IN TSUNAMI DISASTER REDUCTION Planning Increasing Tsunami Hazard perception by the public Enhancing Awareness through public education Future challenges in tsunami disaster reduction 10. PREPAREDNESS - WHAT DO YOU NEED TO KNOW & DO TO SAVE YOUR LIFE Tsunami Safety Rules What you can do Before, During and After a Tsunami Strikes Inspecting your Home after its damage by a Tsunami Overall Tsunami Mitigation Efforts - What More You Should Know and Do 11. USEFUL ADDRESSES - INTERNET LINKS FOR FURTHER INFORMATION AND READING 12. LIST OF PUBLICATIONS RELATED TO TSUNAMI HAZARD MITIGATION IOC/ITSU-XVIII/15 1. INTERGOVERNMENTAL OCEANOGRAPHIC COMMISSION & ITS TSUNAMI PROGRAMME - GLIMPSE INTO THE PAST. Historical Background The great destruction and loss of life caused by the May 1960 Chilean tsunami prompted a large number of countries and territories to inquire about joining into a Pacific Tsunami Warning System (TWS). The great Alaskan earthquake of 1964 generated another devastating tsunami that affected a good part of the Pacific. This tsunami disaster focused additional attention to the need for an International Tsunami Warning System under the auspices of a United Nations organization. Recognizing the importance of providing timely warnings of the approach of potentially catastrophic tsunamis in the Pacific Ocean, UNESCO/IOC accepted the challenge. An agreement was reached for the U.S. Warning System to be integrated with the Systems of Japan, USSR, Chile, and of other regional centers, to become a truly International Tsunami Warning System. The Tsunami Warning Center in Honolulu, Hawaii, was designated as the headquarters for the Pacific Tsunami Warning Center (PTWC). The International Tsunami Information Center (ITIC) and the International Coordination Group for the Tsunami Warning System in the Pacific (ICG/ITSU) were formally established in accordance with the UNESCO/IOC Resolution #1 entitled "International Aspects of the Tsunami Warning System in the Pacific", adopted in Paris at the Fourth Session of UNESCO General Assembly, on November 12, 1965. Thus, UNESCO/IOC played a very important lead role in beginning a very successful and cost-effective, disaster warning and mitigation program, twenty-five years before the International Decade on Natural Disaster Reduction (IDNDR) begun. The International Coordination Group for the Tsunami Warning System in the Pacific (ICG-ITSU). The International Coordination Group for the Tsunami Warning System in the Pacific (ICG/ITSU) was established as a subsidiary body of IOC. ICG-ITSU membership and participation in the International Tsunami Warning System has increased dramatically over the years. From the original six nations that joined in 1965, twenty-eight nations are now members. More Member Nations are expected to join in the future with the extension of the Tsunami Programme to other geographical areas, which are at risk from tsunamis. The ICG/ITSU meets every two years in a member state to coordinate and review the activities of the International Tsunami Warning System (ITWS), to decide on action items and recommend improvements. Its mandate is to effect coordination that will help mitigate the effects of tsunamis throughout the Pacific and elsewhere. The International Tsunami Information Centre (ITIC) and its Mandate ITIC mandate and functions evolved and expanded over the years. Today, ITIC is given the mandate of mitigating the effects of Tsunamis throughout the Pacific by supporting Member States of the ICG/ITSU in developing and improving preparedness for tsunamis by: a) monitoring and seeking to improve the Tsunami Warning System for the Pacific; b) by gathering and disseminating knowledge on tsunamis, and fostering tsunami research; c) by bringing a knowledge of the Tsunami Warning System and ITIC to nonmember states, and information on how to become participants through ICG/ITSU; d) by conducting post-disaster surveys for the purpose of documentation and understanding of the tsunami disaster; e) by assisting in organizing disaster preparedness and education activities, aimed at tsunami disaster reduction. IOC/ITSU-XVIII/15 page 2 2. TSUNAMI - TOP 10 QUESTIONS FREQUENTLY ASKED What is a tsunami? The phenomenon we call tsunami is a series of large waves of extremely long wavelength and period usually generated by a violent, impulsive undersea disturbance or activity near the coast or in the ocean. When a sudden displacement of a large volume of water occurs, or if the sea floor is suddenly raised or dropped by an earthquake, big tsunami waves can be formed by forces of gravity. The waves travel out of the area of origin and can be extremely dangerous and damaging when they reach the shore. The word tsunami (pronounced tsoo-nah'-mee) is composed of the Japanese words "tsu" (which means harbor) and "nami" (which means "wave"). Often the term, "seismic or tidal sea wave" is used to describe the same phenomenon, however the terms are misleading, because tsunami waves can be generated by other, non seismic disturbances such as volcanic eruptions or underwater landslides, and have physical characteristics different of tidal waves. The tsunami waves are completely unrelated to the astronomical tides - which are caused by the extraterrestrial, gravitational influences of the moon, sun, and the planets. Thus, the Japanese word "tsunami", meaning "harbor wave" is the correct, official and all-inclusive term. It has been internationally adopted because it covers all forms of impulsive wave generation. How do earthquakes generate tsunamis? By far, the most destructive tsunamis are generated from large, shallow earthquakes with an epicenter or fault line near or on the ocean floor. These usually occur in regions of the earth characterized by tectonic subduction along tectonic plate boundaries. The high seismicity of such regions is caused by the collision of tectonic plates. When these plates move past each other, they cause large earthquakes, which tilt, offset, or displace large areas of the ocean floor from a few kilometers to as much as a 1,000 km or more. The sudden vertical displacements over such large areas, disturb the ocean's surface, displace water, and generate destructive tsunami waves. The waves can travel great distances from the source region, spreading destruction along their path. For example, the Great 1960 Chilean tsunami was generated by a magnitude 8.3 earthquake that had a rupture zone of over 1,000 km. Its waves were destructive not only in Chile, but also as far away as Hawaii, Japan and elsewhere in the Pacific. It should be noted that not all earthquakes generate tsunamis. Usually, it takes an earthquake with a Richter magnitude exceeding 7.5 to produce a destructive tsunami. How do volcanic eruptions generate tsunamis? Although relatively infrequent, violent volcanic eruptions represent also impulsive disturbances, which can displace a great volume of water and generate extremely destructive tsunami waves in the immediate source area. According to this mechanism, waves may be generated by the sudden displacement of water caused by a volcanic explosion, by a volcano's slope failure, or more likely by a phreatomagmatic explosion and collapse/engulfment of the volcanic magmatic chambers. One of the largest and most destructive tsunamis ever recorded was generated in August 26, 1883 after the explosion and collapse of the volcano of Krakatoa (Krakatau), in Indonesia. This explosion generated waves that reached 135 feet, destroyed coastal towns and villages along the Sunda Strait in both the islands of Java and Sumatra, killing 36, 417 people. IOC/ITSU-XVIII/15 page 3 It is also believed that the destruction of the Minoan civilization in Greece was caused in 1490 B.C. by the explosion/collapse of the of the volcano of Santorin in the Aegean Sea. How do submarine landslides, rock falls and underwater slumps generate tsunamis? Less frequently, tsunami waves can be generated from displacements of water resulting from rock falls, icefalls and sudden submarine landslides or slumps. Such events may be caused impulsively from the instability and sudden failure of submarine slopes, which are sometimes triggered by the ground motions of a strong earthquake. For example in the 1980's, earth moving and construction work of an airport runway along the coast of Southern France, triggered an underwater landslide, which generated destructive tsunami waves in the harbor of Thebes. Major earthquakes are suspected to cause many underwater landslides, which may contribute significantly to tsunami generation. For example, many scientists believe that the 1998 tsunami , which killed thousands of people and destroyed coastal villages along the northern coast of Papua-New Guinea, was generated by a large underwater slump of sediments, triggered by an earthquake. In general, the energy of tsunami waves generated from landslides or rock falls is rapidly dissipated as they travel away from the source and across the ocean, or within an enclosed or semi-enclosed body of water - such as a lake or a fjord. However, It should be noted, that the largest tsunami wave ever observed anywhere in the world was caused by a rock fall in Lituya Bay Alaska on July 9, 1958. Triggered by an earthquake along the Fairweather fault, an approximate 40 million cubic meter rock fall at the head of the bay generated a wave, which reached the incredible height of 520-meter wave ( 1,720 feet) on the opposite side of the inlet. A initial huge solitary wave of about 180 meters (600 feet) raced at about 160 kilometers per hour (100 mph) within the bay debarking trees along its path. However, the tsunami's energy and height diminished rapidly away from the source area and, once in the open ocean, it was hardly recorded by tide gauge stations. Can asteroids, meteorites or man-made explosions cause tsunamis? Fortunately for mankind, it is indeed very rare for a meteorite or an asteroid to reach the earth. No asteroid has fallen on the earth within recorded history. Most meteorites burn as they reach the earth's atmosphere. However, large meteorites have hit the earth's surface in the distant past. This is indicated by large craters, which have been found in different parts of the earth. Also, it is possible that an asteroid may have fallen on the earth in prehistoric times - the last one some 65 million years ago during the Cretaceous period. Since evidence of the fall of meteorites and asteroids on earth exists, we must conclude that they have fallen also in the oceans and seas of the earth, particularly since four fifths of our planet is covered by water. The fall of meteorites or asteroids in the earth's oceans has the potential of generating tsunamis of cataclysmic proportions. Scientists studying this possibility have concluded that the impact of moderately large asteroid, 5-6 km in diameter, in the middle of the large ocean basin such as the Atlantic Ocean, would produce a tsunami that would travel all the way to the Appalachian Mountains in the upper two-thirds of the United States. On both sides of the Atlantic, coastal cities would be washed out by such a tsunami. An asteroid 5-6 kilometers in diameter impacting between the Hawaiian Islands and the West Coast of North America, would produce a tsunami which would wash out the coastal cities on the West coasts of Canada, U.S. and Mexico and would cover most of the inhabited coastal areas of the Hawaiian islands, IOC/ITSU-XVIII/15 page 4 Conceivably tsunami waves can also be generated from very large nuclear explosions. However, no tsunami of any significance has ever resulted from the testing of nuclear weapons in the past. Furthermore, such testing is presently prohibited by international treaties. Where and how frequently are tsunamis generated? Tsunamis are disasters that can be generated in all of the world's oceans, inland seas, and in any large body of water. Each region of the world appears to have its own cycle of frequency and pattern in generating tsunamis that range in size from small to the large and highly destructive events. Most tsunamis occur in the Pacific Ocean and its marginal seas. The reason is that the Pacific covers more than one-third of the earth’s surface and is surrounded by a series of mountain chains, deep-ocean trenches and island arcs called the “ring of fire” - where most earthquakes occur (off the coasts of Kamchatka, Japan, the Kuril Islands, Alaska and South America). Many tsunamis have also been generated in the seas, which border the Pacific Ocean. Tsunamis are generated by shallow earthquakes all around the Pacific, but those from earthquakes in the tropical Pacific tend to be modest in size. While such tsunamis in these areas may be devastating locally, their energy decays rapidly with distance. Usually, they are not destructive a few hundred kilometers away from their sources. That is not the case with tsunamis generated by great earthquakes in the North Pacific or along the Pacific coast of South America. On the average of about half-a-dozen times per century, a tsunami from one of these regions sweeps across the entire Pacific, is reflected from distant shores, and sets the entire ocean in motion for days. For example, the 1960 Chilean tsunami caused death and destruction throughout the Pacific. Hawaii, Samoa, and Easter Island all recorded runups exceeding 4 m; 61 people were killed in Hawaii. In Japan 200 people died. A similar tsunami in 1868 from northern Chile caused extensive damage in the Austral Islands, Hawaii, Samoa and New Zealand. Although not as frequent, destructive tsunamis have been also been generated in the Atlantic and the Indian Oceans, the Mediterranean Sea and even within smaller bodies of water, like the Sea of Marmara, in Turkey. In 1999, a large earthquake along the North Anatolian Fault zone, generated a local tsunami, which was particularly damaging in the Bay of Izmit. In the last decade alone, destructive tsunamis have occurred in Nicaragua (1992), Indonesia (1992, 1994, 1996), Japan (1993), Philippines (1994), Mexico (1995), Peru (1996, 2001), Papua-New Guinea (1998), Turkey (1999), and Vanuatu (1999). How does tsunami energy travel across the ocean and how far can tsunamis waves reach? Once a tsunami has been generated, its energy is distributed throughout the water column, regardless of the ocean's depth. A tsunami is made up of a series of very long waves. The waves will travel outward on the surface of the ocean in all directions away from the source area, much like the ripples caused by throwing a rock into a pond. The wavelength of the tsunami waves and their period will depend on the generating mechanism and the dimensions of the source event. If the tsunami is generated from a large earthquake over a large area, its initial wavelength and period will be greater. If the tsunami is caused by a local landslide, both its initial wavelength and period will be shorter. IOC/ITSU-XVIII/15 page 5 The period of the tsunami waves may range from 5 to 90 minutes. The wave crests of a tsunami can be a thousand km long, and from a few to a hundred kilometers or more apart as they travel across the ocean. On the open ocean, the wavelength of a tsunami may be as much as two hundred kilometers, many times greater than the ocean depth, which is on the order of a few kilometers. In the deep ocean, the height of the tsunami from trough to crest may be only a few centimeters to a meter or more - again depending on the generating source. Tsunami waves in the deep ocean can travel at high speeds for long periods of time for distances of thousands of kilometers and lose very little energy in the process. The deeper the water, the greater the speed of tsunami waves will be. For example, at the deepest ocean depths the tsunami wave speed will be as much as 800 km/hr, about the same as that of a jet aircraft. Since the average depth of the Pacific ocean is 4000 m (14,000 feet) , tsunami wave speed will average about 200 m/s or over 700 km/hr (500 mph). At such high speeds, a tsunami generated in Aleutian Islands may reach Hawaii in less than four and a half hours. In 1960, great tsunami waves generated in Chile reached Japan, more than 16,800 km away in less than 24 hours, killing hundreds of people. Why Tsunamis Cannot Be Seen at Sea or from the Air? In the deep ocean, tsunami wave amplitude is usually less than 1 m (3.3 feet). The crests of tsunami waves may be more than a hundred kilometers or more away from each other. Therefore, passengers on boats at sea, far away from shore where the water is deep, will not feel nor see the tsunami waves as they pass by underneath at high speeds. The tsunami may be perceived as nothing more than a gentle rise and fall of the sea surface. The Great Sanriku tsunami, which struck Honshu, Japan, on June 15, 1896, was completely undetected by fishermen twenty miles out to sea. The deep-water height of this tsunami was only about 40 centimeters when it passed them and yet, when it arrived on the shore, it had transformed into huge waves that killed 28,000 people, destroyed the port of Sanriku and villages along 275 km of coastline. For the same reason of low amplitude and very long periods in the deep ocean, tsunami waves cannot be seen nor detected from the air. From the sky, tsunami waves cannot be distinguished from ordinary ocean waves. What are the Factors of Destruction from Tsunamis? There are three: inundation, wave impact on structures, and erosion. Strong, tsunami- induced currents lead to the erosion of foundations and the collapse of bridges and seawalls. Flotation and drag forces move houses and overturn railroad cars. Considerable damage is caused by the resultant floating debris, including boats and cars that become dangerous projectiles that may crash into buildings, break power lines, and may start fires. Fires from damaged ships in ports or from ruptured coastal oil storage tanks and refinery facilities, can cause damage greater than that inflicted directly by the tsunami. Of increasing concern is the potential effect of tsunami draw down, when receding waters uncover cooling water intakes of nuclear power plants. IOC/ITSU-XVIII/15 page 6 What determines how destructive a tsunami will be near the origin and at a distant shore? Tsunamis arrive at a coastline as a series of successive crests (high water levels) and troughs (low water levels) - usually occurring 10 to 45 minutes apart. As they enter the shallow waters of coastlines, bays, or harbors, their speed decreases to about 50-60 km/hr. For example, in 15 m of water the speed of a tsunami will be only 45 km/hr. However 100 or more kilometers away, another tsunami wave travels in deep water towards the same shore at a much greater speed, and still behind it there is another wave, traveling at even greater speed. As the tsunami waves become compressed near the coast, the wavelength is shortened and the wave energy is directed upward - thus increasing their heights considerably. Just as with ordinary surf, the energy of the tsunami waves must be contained in a smaller volume of water, so the waves grow in height. Even though the wavelength shortens near the coast, a tsunami will typically have a wavelength in excess of ten kilometers when it comes ashore. Depending on the water depth and the coastal configuration, the waves may undergo extensive refraction - another process that may converge their energy to particular areas on the shore and thus increase the heights even more. Even if a tsunami wave may have been 1 meter of less in the deep ocean, it may grow into a huge 30-35 meter wave when it sweeps over the shore. Thus, tsunami waves may smash into the shore like a wall of water or move in as a fast moving flood or tide - carrying everything on their path. Either way, the waves become a significant threat to life and property. If the tsunami waves arrive at high tide, or if there are concurrent storm waves in the area, the effects will be cumulative and the inundation and destruction even greater. The historic record shows that there have been many tsunamis that have struck the shores with devastating force, sometimes reaching heights of more than 30-50 meters. For example, the 1946 tsunami generated by an earthquake off Unimak island in Alaska's Aleutian Islands, reached heights of more than 35 meters, which destroyed a reinforced concrete lighthouse and killed its occupants. Finally, the maximum height a tsunami reaches on shore is called the runup. It is the vertical distance between the maximum height reached by the water on shore and the mean sea level surface. Any tsunami runup over a meter is dangerous. The flooding by individual waves will typically last from ten minutes to a half-hour, so the danger period can last for hours. Tsunami runup at the point of impact will depend on how the energy is focused, the travel path of the tsunami waves, the coastal configuration, and the offshore topography. Small islands with steep slopes usually experience little runup - wave heights there are only slightly greater than on the open ocean. This is the reason that islands with steep-sided fringing or barrier reefs are only at moderate risk from tsunamis. However, this is not the case for islands such as the Hawaiian or the Marquesas. Both of these island chains do not have extensive barrier reefs and have broad bays exposed to the open ocean. For example, Hilo Bay at the island of Hawaii and Tahauku Bay at Hiva Oa in the Marquesas are especially vulnerable. The 1946 Aleutian tsunami resulted in runup, which exceeded 8 m at Hilo and 10 m at Tahauku; 59 people were killed in Hilo and two in Tahauku. Similarly, any gap in a reef puts the adjacent shoreline at risk. The local tsunami from the Suva earthquake of 1953 did little damage because of Fiji's extensive offshore reefs. However, two villages on the island of Viti Levu, located on opposite gaps in the reef, were extensively damaged and five people were drowned. What are some of the largest historical tsunamis? Destructive tsunamis have occurred in all of the world's oceans and seas. In the last half of the 20th Century, Pacific-wide, destructive tsunamis occurred in 1946, 1952, 1957, 1960, and 1964. (Many more tsunamis in inland seas around the periphery of the Pacific, were IOC/ITSU-XVIII/15 page 7 extremely destructive locally and claimed thousands of lives Such localized tsunamis occurred in 1975 , 1983, 1985, 1992, 1993, 1995, 1998, 1999 and 2001. The 1 April 1946 Aleutian Tsunami - One of the most destructive Pacific-wide tsunamis was generated by a magnitude 7.8 earthquake near Unimak Island in Alaska's Aleutian Island Chain. A huge wave of 35 meters destroyed completely the U.S. Coast Guard's Scotch Cap lighthouse on Unimak and killed all five of its occupants. The lighthouse was a steel-reinforced concrete structure standing about 30 meters above sea level. Without warning, destructive tsunami waves reached the Hawaiian Islands, five hours later, causing considerable damage and loss of life. The waves completely obliterated Hilo's waterfront on the island of Hawaii, killing 159 people there. Altogether a total 165 people lost their lives from this tsunami, including children attending school at Hawaii's Laupahoehoe Point, where waves reaching up to 8 m destroyed also a hospital. Damage was estimated at $26 million (in 1946 dollars). In 1948, and as a result of this tsunami, the U.S. established a Pacific Tsunami Warning Center in Hawaii. The 4 November 1952 Kamchatka Tsunami - A strong earthquake (magnitude 8.2) off the coast of Kamchatka Peninsula generated a great destructive Pacific-wide tsunami. Its waves struck the Kamchatka Peninsula, the Kuril Islands and other areas of Russia's Far East, causing considerable damage and loss of life. The tsunami was widely observed and recorded in Japan, but there was no loss of life or damage there. There was considerable damage in the Hawaiian Islands and some damage in Peru and Chile. The tsunami was recorded or observed throughout the islands of the Pacific. In New Zealand waves reached height of 1m. In Alaska, in the Aleutian Islands and in California waves of up to 1.4 meters were observed or recorded. By far the largest waves outside the generating area were observed in the Hawaiian Islands. Fortunately, no human lives were lost in Hawaii from this tsunami, but damage was extensive, estimates ranging from $800,000- $1,000,000 (in 1952 dollars). The tsunami caused damage on Midway Island. Elsewhere in the Hawaiian island chain, the waves destroyed boats and piers, knocked down telephone lines, and caused extensive beach erosion. In some locations, tsunami waves were destructive in certain locations but hardly noticeable at others. The north shore of the Island of Oahu experienced higher waves of up to 4.5 meters. On the south shore of the island, the tsunami was powerful enough to throw a cement barge in the Honolulu Harbor into a freighter. The island of Hawaii experienced run up to 6.1 meters. In Hilo, a small bridge connecting Coconut Island to the shore was destroyed by one of the tsunami waves lifting it off its foundation, then smashing it down. The effects of the tsunami in the generating area in Kamchatka, varied significantly. From Kamchatka Peninsula to Kronotsky Peninsula the wave heights ranged from zero to 5 meters. From Kronotsky Peninsula to Cape Shipursky the heights ranged from 4-13 meters. The highest wave of 13 meters was the third and was observed at Olga Bay, where it caused considerable damage. Travel time of the first tsunami wave to Olga Bay was approximately 42 minutes after the earthquake. From Cape Shipursky to Cape Povorotny, the tsunami waves ranged from 1 to 10 meters and caused considerable loss of life and damage. At Avachinskaia Bay the tsunami height was 1.2 meters and its travel time was about 30 minutes. From Cape Povorotny to Cape Lopatkka the waves ranged from 5 to 15 meters. At Khodutka Bay a cutter was thrown 500 meters back from shore. On the West coast of Kamchatka Peninsula, the maximum tsunami runup at Ozernoe was 5 meters. At Alaid Island of the Kuril Island group, run up was 1.5 meters. At Shumshu Island it ranged from 7-9 meters. At Paramushir Island the waves ranged from 4-18.4 meters. At Severo IOC/ITSU-XVIII/15 page 8 - Kurilsk on Paramushir Island, the second wave was the highest reaching maximum run up of 15 meters. It destroyed most of the town and caused considerable loss of life. At Onekotan Island tsunami run up was 9 meters, while at Shiashkoton Island it was 8 meters and at Iturup Island 2.5 meters. Waves of up to 2 meters were observed at the Komandorsk Islands and at Okhotsk. At Sakhalin - Korsakov a 1-meter tsunami wave was observed. The 9 March 1957 Aleutian Tsunami - On March 9, 1957, an 8.3 magnitude earthquake south of the Andreanof Islands, in the Aleutian Islands of Alaska - in the same general area as that of April 1, 1946 - generated a Pacific-wide tsunami. Although no lives were lost, there was extensive destruction of property in the Hawaiian Islands, with damage estimated at approximately $5 million (1957 dollars). The waves were particularly high on the north shore of the island of Kauai where they reached a maximum height of 16 meters, flooding the highway and destroying houses and bridges. This was twice the height of the 1946 tsunami. At Hilo, Hawaii, the tsunami runup reached 3.9 m and there was damage to numerous buildings along the waterfront. Within Hilo Bay, Coconut Island was covered by 1 m of water and the bridge connecting it to the shore, as in 1952, was again destroyed. The 22 May 1960 Chilean Tsunami - The largest earthquake ( magnitude 8.6) of the 20th century occurred on May 22, 1960 off the coast of south central Chile. It generated a Pacific-wide tsunami, which was destructive locally in Chile and throughout the Pacific Ocean. The tsunami killed an estimated 2,300 people in Chile. There was tremendous loss of life and property in the Hawaiian Islands, in Japan and elsewhere in the Pacific. Destructive waves in Hilo, Hawaii, destroyed the waterfront and killed 61 people. Total damage was estimated at more than $500 million (1960 dollars). The 28 March 1964 Alaska Tsunami - The largest earthquake of the 20th Century in the northern hemisphere, with a magnitude 8.4, affected an area in Alaska that was almost 1600 km long and more than 300 km wide - extending from Valdez to the Trinity Islands, southwest of Kodiak Island in the Gulf of Alaska. The earthquake caused areas to be lifted by as much as 15 m (50 feet) in certain areas, while many other areas subsided greatly. In addition to many local tsunamis generated within the Prince William Sound, vertical crustal displacements averaging 1.8 m (6 ft.) over an area of about 300,000 square kilometers (115,000 square miles) extending in the Gulf of Alaska's continental shelf, generated a Pacific-wide tsunami. Its waves were very destructive in southeastern Alaska, in Vancouver Island (British Columbia), and in the U.S. States of Washington, California and Hawaii. The tsunami killed more than 120 people and caused more than $106 million in damages, making it the costliest ever to strike the Western United States and Canada. Five of Alaska's seven largest communities were devastated by the combination of earthquake and tsunami wave damage. Alaska's fishing industry and most seaport facilities were virtually destroyed. Tsunami waves at Kodiak Island washed away a total of 158 houses and buildings within two blocks of the waterfront. Fishing boats were carried hundreds of meters inland. The 1964 tsunami waves caused also extensive damage in Vancouver Island (British Columbia), and in the states of Washington, California and Hawaii, in the U.S.. The waves affected the entire California coastline, but were particularly high from Crescent City to Monterey ranging from 2.1 - 6.3 meters (7-21 feet). Hardest hit was Crescent City, California,__ where waves reaching as much as 6 meters (20-21 feet) destroyed half of the waterfront business district. Eleven persons lost their lives there. At Santa Cruz Harbor, the tsunami waves reached as high as 3.3 meters (11 feet) causing some damage. There was extensive damage in San Francisco Bay, the marinas in Marin County and at the Noyo, Los Angeles and IOC/ITSU-XVIII/15 page 9 Long Beach harbors. Estimated losses in California were between $1,500,000 and $2,375,000 (1964 dollars), while at Crescent City tsunami damage was estimated at $7,414,000. Why are locally generated tsunamis so dangerous? A locally generated tsunami may reach a nearby shore in less than ten minutes. There is not sufficient time for the Pacific Tsunami Warning Center or for local authorities to issue a warning. For people living near the coast, the shaking of the ground is a warning that a tsunami may be imminent. For tsunamis from more distant sources, however, accurate warnings of when a tsunami might arrive are possible because tsunamis travel at a known speed. 3. TSUNAMI WARNING SYSTEM - A VIGILANT 24 HOUR WATCH Membership The following twenty-eight nations are now participating members of ITSU in the Pacific: Australia, Canada, Chile, China, Colombia, Cook Islands, Costa Rica, Democratic People's Republic of Korea, Ecuador, Fiji, France, Guatemala, Indonesia, Japan, Mexico, New Zealand, Nicaragua, Peru, Philippines, Republic of Korea, Singapore, Thailand, Federation of Russia, United States of America USA, and Western Samoa. Organization The frequent threat of tsunamis in the Pacific prompted the international community of nations to participate in the Tsunami Warning System in the Pacific under the auspices of IOC. The existing Tsunami Warning Systems of USA, Japan, USSR, Chile, and of other regional centers were integrated and now form the nucleus of the International Tsunami Warning System in the Pacific. Member states maintain stations for the ITWS. The System makes use of 69 seismic stations, 65 tide stations, satellite communications and 101 dissemination points scattered throughout the Pacific Basin under the varying control of the member states of ITSU. In addition to coordinating the international aspects of the Warning System, the IOC Tsunami Programme promotes, coordinates, sponsors and supports efforts of tsunami preparedness that will mitigate the impact of future tsunamis to all the ITSU member countries and island nations of the Pacific. This endeavour, promotes systematic tsunami inundation mapping programmes and educational campaigns to prepare vulnerable coastal communities for a potential tsunami disaster. Programme Management Overall Tsunami Programme management and coordination is the responsibility of IOC. Its ICG/ITSU Group meets every two years in a member state to coordinate and review activities of the International Tsunami Warning System (ITWS), to decide on action items, and to recommend improvements. In close cooperation with ICG/ITSU, the International Tsunami Information Center (ITIC) is responsible for day-to-day coordination on action items related to the ITWS, as well as on other mandated functions related to tsunami disaster mitigation. The Centre maintains a complete library of publications related to tsunamis and a full file of data as obtained from World Data Centers ( WDCs) and the real-time Tsunami Warning System. These resources serve as the basis for information services and as research materials for visiting scientists from ITSU member countries and experts attending an annual tsunami training course hosted by ITIC. Both ITIC and ICG/ITSU continuously monitor the results of current tsunami research in order to find applications which may result in improvements to the Tsunami IOC/ITSU-XVIII/15 page 10 Warning System. For this reason, they maintain close contact with IUGG (International Union Of Geodesy and Geophysics) and many other national and international scientific organizations. Additionally, the IOC Tsunami Programme sponsors and holds educational workshops on tsunami preparedness, often in conjunction with the IUGG Tsunami Committee meetings. Main Operational Components The Pacific Tsunami Warning Center (PTWC) in Honolulu, Hawaii, is the main operational component of the Pacific Tsunami Warning System. It is operated by the U.S. National Oceanic and Atmospheric Administration's (NOAA), National Weather Service. PTWC provides national authorities in the Pacific Basin with watch and warning information for tsunamis that pose a Pacific-wide threat and also serves as the regional Tsunami Warning Center for the Hawaiian Islands. Because of warning time constraints, national regional centers of ITSU member countries are also responsible for issuing tsunami warnings in their immediate jurisdiction. For example, the Alaska Tsunami Warning Center (ATWC) in Palmer, Alaska, operated also by the U.S., serves as the regional Tsunami Warning Center for Alaska, British Columbia, Washington, Oregon, and California. The Tsunami Warning Center of the Japan Meteorological Agency (JMA) issues warnings for tsunamis generated near Japan. PTWC monitors, on a 24-hour basis, all the seismological and tidal stations throughout the Pacific Basin, evaluates potential tsunamis and disseminates tsunami watch and warning information. Earthquake data is collected from seismic stations operated by ITSU participating nations, by ATWC, the U.S. Geological Survey's National Earthquake Information Centre, and from several international sources such as the Japan Meteorological Agency. Sea-level (or tidal) data is provided by ITSU member nations, by NOAA's National Ocean Service, by the ATWC, by GLOSS and by university monitoring networks. 4. BASIC FACTS ABOUT THE OPERATION OF THE PACIFIC TSUNAMI WARNING SYSTEM - HOW IT WORKS The objective of the Tsunami Warning System is to detect, locate, and determine the magnitude of potentially tsunamigenic earthquakes occurring in the Pacific Basin or its immediate margins, and to issue timely tsunami watches and warnings. The System makes use of an extensive network of seismic and tide stations, which have the ability to transmit data immediately to the operational headquarters at the Pacific Tsunami Warning Center (PTWC) in Hawaii. Functioning of the System begins with the detection of an earthquake, which has a magnitude and location that make it potentially capable of generating a tsunami. The earthquake has to be of sufficient magnitude to trigger the alarm attached to the seismograph at the station where it is being recorded. The alarm thresholds are set so that ground vibrations of the amplitude and duration associated with an earthquake of approximate magnitude 6.5 or greater on the Richter Scale anywhere in the Pacific region will cause them to activate. Personnel at the station immediately interpret their seismographs and send their readings to the Pacific Tsunami Warning Center (PTWC) in Honolulu. Upon receipt of a report from one of the participating seismic observatories or as a consequence of the triggering of their own seismic alarm, PTWC personnel send messages requesting data from the observatories in the system. When sufficient data has been received so that the earthquake can be located and the magnitude computed, a decision is made as to further action. If the earthquake is strong IOC/ITSU-XVIII/15 page 11 enough to cause a tsunami and is located in an area where this is possible, participating tide stations near the epicenter are requested to monitor their tide gauges. Watch and Warning Communications The major responsibility of the TWS is the dissemination of tsunami watch and/or warning information. If the location and magnitude of an earthquake meet the established criteria for tsunami generation, a watch or warning is issued for the Pacific Ocean and marginal seas to apprise or warn of an imminent tsunami hazard. Tsunami watches, warnings and information bulletins are disseminated to appropriate emergency officials and the general public by a variety of communication methods. The dissemination program is a sophisticated cooperative venture using existing national and international communication facilities. Tsunami watches and warnings are disseminated by PTWC to over 100 dissemination points scattered throughout the Pacific Basin under the varying control of ITSU member states. These major dissemination points are then responsible for further dissemination to hundreds of other points within their geographical jurisdictions. Tsunami watch, warning and information bulletins are issued by PTWC and sometimes by ATWC or JMA - if within their jurisdictional area. The bulletins are provided to local, state, national and international users as well as the media. In turn, these users disseminate the tsunami information to the public - generally over commercial radio and television channels. Broadcasts of urgent marine warnings and related tsunami information are also sent to coastal users equipped with medium frequency(MF) and very high frequency (VHF) marine radios. Watch Bulletins: Watch bulletins are issued to the dissemination agencies for all earthquakes of magnitude 7 or greater occurring in the Aleutian Islands, and all earthquakes of magnitude 7.5 or greater occurring elsewhere in the Pacific. A watch may also be disseminated by PTWC upon the issuance of a warning by a regional warning center. Since the regional systems use different criteria for their dissemination, a watch may at times be issued for earthquakes with magnitude less than 7.5. A tsunami watch with additional predicted tsunami arrival times is issued for a geographic area defined by the distance the tsunami could travel in a subsequent time period - usually within three hours of tsunami travel time. Tsunami Warning Issuance and Cancellation: When reports from tide stations nearest the earthquake region show that a tsunami poses a threat to the population in a part or all of the Pacific, a warning is transmitted to the dissemination agencies for relay to the public. The warning information may include also predicted tsunami arrival times at selected coastal communities. The warning may be initially provided to the area closest to the tsunami- generating region. Then, if additional data is received indicating that the tsunami is a Pacific- wide threat, the warning is extended to the entire Pacific Basin. Local authorities and emergency managers are responsible for evacuating people from endangered areas under a tsunami warning. Subsequently, if tide station reports indicate that either a negligible tsunami or no tsunami has been generated, PTWC issues a cancellation of the warning. Testing of Pacific Tsunami Warning Communications: With general guidance from IOC, both ICG/ITSU, and ITIC play a significant role in coordinating cooperation among ITSU nations and in establishing communication requirements, procedures, and the monitoring of the results. Also, the communications are tested monthly by PTWC with dummy messages. These tests are monitored for minimum message travel times to ensure efficiency of transmission. The dissemination points, in turn, forward the messages to many more points in their respective local areas. IOC/ITSU-XVIII/15 page 12 PTWC publishes regularly the Communication Plan for the Tsunami Warning System. This Plan contains general information about TWS in the Pacific, key definitions, information about tidal and seismic stations, communications requirements, methods applicable to each country, and message types, criteria and formats. Response and Regional Warnings for Locally Generated Tsunamis Since a tsunami travels at a speed which may exceed 600 km/s in the deeper parts of the ocean, when a potentially tsunamigenic earthquake occurs, there is urgent need for rapid data handling and communication. Because of the time spent in collecting seismic and tidal data, the warnings issued by PTWC cannot protect areas against local tsunamis in the first hour after generation. For this reason, regional warning systems have been established in some areas. Generally, the regional systems have data from a number of seismic and tide stations telemetered to a central headquarters. Nearby earthquakes are located, usually in 15 minutes or less, and a warning based on seismological evidence is released to the population of the area. Since the warning is often issued on the basis of seismic data alone, watches or even warnings will occasionally be issued when tsunamis have not been generated. Since the warning are issued only to restricted areas and confirmation of the existence or nonexistence of a tsunami is rapidly obtained, dislocations of populations are minimized. To limit the number of agencies to be contacted, warnings are generally issued to only one agency in each country, territory, or administrative area. In vulnerable areas, national dissemination and civil defense agencies have the continuing responsibility for educating the public about the dangers of tsunamis and for developing safety measures that must be taken to avoid loss of life and to reduce property damage. The IOC Tsunami Programme, through its ITSU Group, encourages national authorities to develop emergency plans for all threatened coastal areas in their jurisdiction, clearly delineating areas of tsunami inundation, evacuation routes and safe areas, and to determine the amount of advance warning needed to insure evacuation. IOC's International Tsunami Information Centre, routinely monitors and evaluates the performance and effectiveness of the Pacific Tsunami Warning System. Recommendations are often included in the ITIC Progress Reports presented at ITSU meetings. These assessments, and the action items and_ recommendations resulting from UNESCO-IOC sponsored ITSU meetings and workshops, provide additional guidelines to national authorities for the most effective data collection, data analysis, tsunami impact assessment and warning dissemination in their respective jurisdiction. 5. RECENT TSUNAMI DISASTERS: SOME FACTS AND FIGURES In spite of IOC's continuous efforts to mitigate the impact of tsunamis, many areas around the Pacific and the world remain vulnerable. The extreme loss of life which resulted from the 17 July 1998 tsunami in Papua-New Guinea is a sad reminder of the enormous task that still faces the IOC sponsored Tsunami Programme. However, it should be emphasized that since the establishment of the International Tsunami Warning System in the Pacific in 1965, all major tsunami events have been detected and timely warnings have been disseminated. Without these warnings and the international cooperation and communications coordinated by IOC, the death toll from tsunami disasters could have been substantially higher. Without the organized data collection sponsored by the Tsunami Programme our understanding of the tsunami disaster and its effects would not be as comprehensive as it is presently. Without this IOC/ITSU-XVIII/15 page 13 understanding and the documentation, operational techniques of forecasting and warning could not have been as effectively implemented. But even with an effective Tsunami Warning System in the Pacific in place and the established IOC active educational program, tsunamis will continue to be a menace to the safety of vulnerable coastal communities around the world. It is extremely difficult to issue warnings for locally generated tsunamis. There is not sufficient time to do it. The record shows that in the last decade of the 20th century and in the first two years of the new millennium, destructive tsunami waves generated by earthquakes in Japan, Indonesia, Nicaragua, Mexico, Papua- New Guinea, Vanuatu, Turkey and Peru have claimed thousands of lives. Within a period of one year alone, three major destructive tsunamis devastated coastal regions of Nicaragua (September 2, 1992), Flores Island, Indonesia (December 12, 1992), and Hokkaido, Japan (July 12, 1993). Giant waves of about 10 meters from the 17 July 1998 tsunami in Papua-New Guinea, killed perhaps as many as 10,000 people. Damage to coastal communities throughout the world has been in the millions of dollars. Most of the deaths and damage to property occurred from locally generated tsunamis, where there was no time to issue___ñ a timely warning. Since 1992, tsunamis have killed more than 5,000 people. Some of the most devastating recent events were the following: Table 1. Tsunamis of the Last Decade (Source: George Pararas-Carayannis - Tsunami Page) Date Place Max. wave Fatalities 2 Sept 1992 Nicaragua 10m 170 12 Dec 1992 Flores Island, Indonesia 26m 1690 12 July 1993 Okushiri, Japan 31m 239 2 June 1994 East Java, Indonesia 14m 238 14 Nov. 1994 Mindoro Island, Philippines 8.5m 49 4 October 1994 Shikotan Is., Russia 10m 0 9 Oct. 1995 Jalisco, Mexico 11m 1 1 Jan 1996 Sulawesi Island, Indonesia 3.4m 9 21 February 1996 Northern Peru ? 12 17 Feb. 1996 Irian Jaya, Indonesia 7.7m 161 21 Feb. 1996 Northern Peru 5m 12 17 July 1998 Papua New Guinea 15m >3000 17 August 1999 Sea of Marmara, Turkey 4m 0 26 November 1999 Pentecost I., Vanuatu 2-3m 5 23 June 2001 Southern Peru 5 20 Description of the following recent tsunami disasters help demonstrate some of the lessons learned from each event, some of the successes in mitigating their effects, and the challenges which still face the Tsunami Programme. IOC/ITSU-XVIII/15 page 14 Nicaragua - 2 September 1992 An earthquake, with magnitude estimated at 7.0, generated a destructive tsunami in Nicaragua. Waves, reached a maximum of 10 meters in height, killed 170 people and left 13,000 homeless. There was no time to issue a warning and Nicaragua, at that time, was not an ITSU member. There had been no studies assessing the tsunami threat for this area. The large tsunami which struck was a complete surprise - even to scientists. It was much larger than what would have been expected for an earthquake of that magnitude, and it did not behave in the traditional way. There were many lessons learned from this event - for scientists as well as officials of disaster organizations. Coastal residents claimed that they did not feel strong ground movements, as it would have been expected, to warn them of an imminent tsunami danger - so they did not run to higher ground. Survivors claimed that they did not hear the characteristic rumbling that a local earthquake is expected to produce. They only felt a minor tremor and assumed there was no tsunami threat. They were totally surprised when waves of up to 10 meters arrived. Analysis of the seismological records showed the fault motion of this particular earthquake to be unusually long in duration and occurring in the top 10 km of oceanic crust - a depth much shallower than that of typical subduction-zone earthquakes. The lesson learned was that each earthquake in certain regions can be unique. It was determined that the magnitude of this earthquake had been underestimated because most of the seismic stations measured only seismic waves of short period. Short period waves had not been readily produced by this quake because of its long duration of faulting. Measurements with long period seismometers would have shown the earthquake magnitude to be five times greater. The quick dissipation of short period waves accounted for the absence of strong ground movements and of rumbling, the coastal residents reported. Scientists learned from this event that unusually large tsunamis can be generated by earthquakes with slow fault motion within subducted sediments. In fact, several similar earthquakes have occurred around the worlds which are now being called "tsunami" earthquakes__-. It is estimated that 5 to 10 percent of all tsunami- generating earthquakes may be "silent" earthquakes of this type. Indonesia - Flores Island - 12 December 1992 An earthquake of magnitude 7.8, with epicenter about 35 km NW off the north coast of the eastern part of Flores Island - near its largest city Maumere - generated a local tsunami which killed 1690 people and destroyed approximately 18,000 houses. The first tsunami wave arrived on the shores of Flores Island within two minutes after the initial shock and reached the north shore within five minutes. Huge tsunami waves with runup of up to 26.2 m completely overrun and destroyed Riang-Kroko, a small village at Cape of Watupajung at the extreme NE end of Flores Island, killing 137 people. Offshore landslides, triggered by the earthquake, may have contributed to the enormous size of the waves which struck this village. Elsewhere on Flores Island the tsunami runup ranged form 2 to 5.2 m, peaking at Kolisia village, an area which also experienced maximum subsidence from the quake's ground movement. Tsunami waves of up to 2.9 meters completely inundated the small, densely populated village of Wuhring [wuhring island], located on a low spit about 3 km NW of the city of Maumere. The waves destroyed most of the houses and killed 87 of the 1400 people living there. Waves with runup of up to 4.6 m also overrun the low lying village of Nebe on Flores island, destroying nearly all the homes and killing two people. On the island of Babi, located IOC/ITSU-XVIII/15 page 15 about 40 km NE of Maumere, waves with maximum runup of 5.6 m killed 263 of the island's 1,093 inhabitants. Japan - Okushiri - 12 July 1993 A large earthquake with a magnitude of 7.8, centered about 15-30 km offshore in the Sea of Japan, struck the Okushiri region of Hokkaido. Five minutes later waves ranging from 5 to 10 meters in height crashed on the closest shores destroying fishing villages and killing 239 people. Field survey documented the maximum wave height to be 31 meters in a small valley on Okushiri Island. Although coastal walls had been erected to offer tsunami protection, they were breached by the large waves which swept up buildings, vehicles, docked vessels and heavy materials at coastal storage areas, transforming them into waterborne missiles that obliterated everything in their path. The collisions sparked electrical and propane gas fires. Access by fire engines was blocked by debris. Fires burned uncontrolled across the ravaged shores of Aonae, a small fishing village on Okushiri's southern peninsula. The Japan Meteorological Agency (JMA) issued a timely and accurate warning for this event, but there was not enough time for the warning to be disseminated everywhere - given the tsunami's short travel time. However, even before the warning was issued, many residents felt the strong motions of the earthquake and, aware of the tsunami danger, saved themselves by fleeing immediately to higher ground. Although the loss of 239 lives was a great tragedy, the Okushiri event clearly demonstrated that the impact of tsunamis can be reduced through warning technology and community education. Such preparedness in Japan greatly reduced the number of casualties. This event has also become the best-documented tsunami disaster in history. Detailed damage assessments of transportation and telecommunications networks, interviews with survivors and local officials, runup and inundation measurements and extensive aerial photography, produced a database especially valuable for future planning in tsunami disaster mitigation. The knowledge gained from this disaster could serve as a model to protect other potentially vulnerable coastal communities. Indonesia - Java - 3 June 1994 A large earthquake (with moment magnitude of 7.8) off the southeastern coast of Java - near the east end of the Java Trench in the Indian Ocean - generated a devastating tsunami that took the lives of more than 200 East Java coastal residents. The most severe tsunami damage occurred along the southern coast of East Java where the waves ranged in height from 1-14m in height. Along the southwestern coast of the Island of Bali the waves ranged from 1-5 meters. As with the Nicaragua earthquake of September 2, 1992., residents along the southeastern East Java coast did not experience strong ground motions, thus indicating that this event was also a "silent" tsunami earthquake. Russia - Shikotan Is. - 4 October 1994 A large, magnitude Ms 8.1 earthquake near Shikotan, one of the South Kuril Islands in Russia, killed 11 people and injured 242 . The quake was associated with very strong ground motions and generated a tsunami. Regional and Pacific wide warnings were issued for the Kuril Islands, Japan, the Hawaiian Islands and the west coast of Canada and the United States. The area most affected by local damaging tsunami waves were primarily Shikotan, Kunashir, Iturup, of the South Kuril Island Group, and Hokkaido, Japan. There was approximately 50 cm of subsidence at Shikotan Island. IOC/ITSU-XVIII/15 page 16 Tsunami runup height measurements were made in Shikotan, Iturup, Kunashir, and small islands between Shikotan and Hokkaido by a team of international scientists. Maximum runup on Shikotan Island was determined to be approximately 10 m high. However none of the reported casualties was attributed to the direct effects of the tsunami. In Japan, the areas most affected were Kushiro, Hachinohe, Chichijima and Hanasaki, in Hokkaido. One person was killed and 140 more were injured. Many more runup measurements along the Hokkaido coast were carried out by a team of scientists from Tohoku University in Japan. An approximately 1.8 m tsunami runup was reported in Nemuro. The tsunami waves were not damaging in Hawaii but were readily recorded. The highest recorded wave at Midway I. was 0.54 meters(peak to trough) and in Kahului, Maui, 0.8 meters (peak to trough). Based on the earthquake aftershock distribution the tsunami generating area was estimated to be only 120 on 100 km. Many things were learned from this particular earthquake, the plate tectonics of the region and the potential of tsunami generation in the Southern Kuril islands-Northern Hokkaido region. There were many similarities in magnitude, and epicenter location of this event with two other quakes which had occurred on 13 and 19 October 1963. In spite of their great magnitude, neither the 1994 quake not these past quakes generated a destructive tsunami outside the source region. Specifically, the October 4, 1994 earthquake (and the 1963 earthquakes) occurred at the Pacific side boundary of a smaller tectonic subplate which includes the Sea of Okhotsk and perhaps a portion of the northern part of the Sea of Japan. This subplate is characterized with large earthquakes such as the 1963 and 1994 events but with lesser vertical subduction and rotational movement, as the North Pacific Plate grinds against it. The whole area appears to be highly fractured in an east-west direction and the crustal displacements appear to be occurring along the boundaries of subplates that may not be longer than 200-250 miles. It appears that the fractured smaller plates along the northern part of the Japanese Trench limit the extent of crustal displacements and therefore the size of the resulting tsunami. The historical record supports this as well. This is the reason why very large magnitude earthquakes from that region produce only locally catastrophic tsunamis. Philippines - Mindoro - 15 November 1994 An earthquake with magnitude of 7.1- centered 11 km N22°W of Baco, Mindoro, near Verde Island - generated a local destructive tsunami. In oriental Mindoro, the combined effects of the earthquake and the tsunami killed a total of 78 people, injured 430, damaged or destroyed 7566 houses in 13 out of 15 municipalities, damaged roads, destroyed or damaged 24 bridges, and sunk numerous fishing boats. There was no time to issue a warning. Approximately five minutes after the tremor, tsunami waves struck along a 40 km stretch of the northern and eastern shoreline of Mindoro island, from Puerto Galera up to Pinamalayan. Also affected were Verde and Baco Islands, north of Mindoro. Waves with a maximum runup of 8.5 meters occurred at Pulong Malaki (Baco Island). Minor waves were also reported at Batangas Bay. Areas hardest hit by the tsunami were in Barangays Malaylay, Old Baco, Wawa, and Baco Islands. Waves with maximum runup of 6 meters caused the greatest destruction, leaving at least 41 persons dead and destroying fishing boats and 1530 houses. Fortunately, being well prepared by the Philippine Civil Defense authorities, most of the inhabitants in the area reacted quickly to the earthquake's natural warnings. After being awakened from their sleep by the IOC/ITSU-XVIII/15 page 17 strong ground motions of the earthquake, they heard a strong jet like sound of water, first receding then coming back. Knowing that a tsunami was coming, they evacuated quickly to higher ground and were thus able to save themselves from the incoming waves. What also helped was the fact that the tide was at its lowest level at that time of the night. Unfortunately, most of the people that died in this area were children and old people that could not move fast enough to higher ground. Almost half of the casualties who drowned were children below 10 years old. The lesson learned was the importance of educational programs and preparedness, particularly for the young. Apparently, such programs are now in place in the Philippines where, in recent years, several tsunami disasters have killed thousands of people. Without such preparedness the death toll for this Mindoro tsunami would have been much greater. Nonetheless, this disaster also indicated the need for these educational programs to be continuous and intensive, particularly in areas known to be vulnerable to the tsunami disaster. Mexico - Manzanillo - 9 October 1995 A large earthquake (Mw = 8.0) occurred along the Northern Middle America Subduction Zone on the Pacific coast, off the states of Jalisco and Colima, in central Mexico. The quake killed about 40 people, injured about 100 and destroyed or severely damaged many buildings near Manzanillo. Strong ground motions were felt strongly in Mexico City. The Manzanillo earthquake was the largest event in 60 years. It generated a moderate local tsunami that affected approximately 200 kilometers of Mexico's coastline from north of Playa de Cuyatlán to south of Tenacatita Bay. Tsunami wave runup ranged from 1 to 5.7 meters, however a maximum wave runup of 11m was reported for one locality. Observes reported a total of four or five waves - the first being the largest. Maximum tsunami inundation occurred in Tenacatita Bay. According to eyewitnesses' reports the water begun to withdraw 15 minutes after the earthquake, then returned like "a fast rising tide". The tsunami was stronger on the northern end of the Bay, near Boca de Iguana, where it destroyed and damaged several houses and carried boats half a kilometer inland. Runup ranged between 3.5 and 5 meters. Fortunately no one was killed. At La Manzanillo, a small town on the southern end of the bay, the tsunami runup was 2 meters.__ The town was completely flooded for about 200 meters inland. Near the entrance to the Port of Manzanillo, strong tsunami-induced currents of up to 12 knots, eroded the banks and caused considerable damage to harbor facilities Tsunami runup heights ranged from 4.75 to 1.75 meters from Manzanillo Bay southward. The tsunami was observed as far away as Puerto Vallarta, 300 kilometers to the north. Peru - Northern - 21 February 1996 A large earthquake (magnitude 7.5) off the northern coastal region of Peru generated a local tsunami. The tsunami affected a 590 km coastal area extending from Pascasmayo, in the department of La Libertad, to the Port of Callao near Lima. The tsunami killed 12, injured 54 (one gravely), damaged 37 homes (15 completely destroyed) and 25 boats (2 destroyed). Some of the fatalities were to line fishermen who were caught on the rocks by the tsunamis. Additional fatalities occurred in the area of Santa, north of Coishco and at the beach of Campo Santa. In the town of Coishco a 30-meter long brick wall was destroyed and several houses were damaged by the waves. At the Port of Chimbote the tsunami inundated 800 m landward of the main dock, overturned a truck and transported a steel guard shack for a distance of 20 m. No major damage was reported. There was flooding at Bahia Los Chimus, about 30 Km IOC/ITSU-XVIII/15 page 18 south of Chimbote all the way to the town's plaza. What is interesting about this event is that most local residents did not feel the ground motions of the earthquake. The tsunami was recorded by mid-Pacific tide gauges. It was 60 cm at Easter Island, and 25 cm at Hilo, Hawaii. Papua-New Guinea - 17 July 1998 A major earthquake (magnitude 7.1) about 12 miles off the northern coast of Papua - New Guinea (PNG), in the Bismarck Sea, generated one of the most destructive and deadly tsunamis to strike this country in recent years. There was no warning. Large waves destroyed primarily three fishing villages along a 30 km stretch of beach west of Atape, in the West Sepik Province of PNG. Most of the deaths occurred at the villages on the shores of the Sissano lagoon area. Minutes after the earthquake shook the region, three successive tsunami waves battered the coastal villages, causing chaos in the darkness of the early night. Two of the villages, one on the spit separating the sea from Sissano lagoon, were completely swept away. At Warapu, a village of 1,800 people, and at Arop, a village of 1800-2,000 people, there were no houses standing. Palm and coconut trees were ripped out completely by the tsunami wave action. According to accounts of survivors, first they felt their homes tremble as the earthquake shook the seabed. Approximately one minute later, they heard a roar described "like a jet fighter landing". In the next few minutes, three huge waves, the largest estimated at 10 meters (more than 30 feet) high, slammed the coastline. The waves swept men, women and children into the sea. Most of the victims were children. The waves were followed by a brief lull, then a fourth less violent wave arrived. Approximately 18 minutes after the earthquake, the sea was quiet again. This tsunami killed more than 3,000 and many more were missing. 6,000 or more people were left homeless. The final death toll for this tsunami disaster may never be known with certainty. It was probably much higher than what has been reported. Lessons learned from this disaster were many and bitter. In spite of continuous efforts by IOC in the past, PNG had not joined the ITSU Group and had no programmes of preparedness or public education about the tsunami hazard. Turkey - Sea of Marmara - 17 August 1999 A large earthquake along the Northern Anatolian fault, known as the Kocaeli Earthquake, generated a local tsunami within the Sea of Marmara. The tsunami was primarily generated by slumping and subsidence of coastal areas, triggered by earthquake motions. An initial recession of the water was observed at both sides of Izmit Bay immediately after the quake, followed subsequently by tsunami waves which had an average runup of 2.5 m. Maximum runup was 4 m in Golcuk which caused damage to the naval base facilities. In fact Golcuk and several coastal areas are now flooded permanently as a result of tectonic subsidence and landslides. Also large coastal portions of the town of Degirmendere remained flooded as a result of subsidence with sea level reaching the second floors of apartment buildings. Similar permanent flooding, but to a lesser extent, occurred also at Karamursel. The tsunami waves from this earthquake had an extremely short period of less than a minute which indicates that the source for this tsunami was the localized subsidence of coastal areas and underwater slumping, rather than larger scale tectonic movements. The lesson learned from this event is that tsunamis can occur in any large body of water since a variety of mechanisms can generate them. Obviously the tsunami risk for the Sea of Marmara needs to be carefully evaluated. Measures must be taken to mitigate the effects of future tsunamis in the area. Better construction and building codes will definitely help. IOC/ITSU-XVIII/15 page 19 Vanuatu - 26 November 1999 A 7.3 magnitude earthquake struck Vanuatu, a group of about 80 islands in the Southwest Pacific that has a population of about 190,000 people. Worst hit was Pentecost, an island with a population of about 12,000. This was the strongest earthquake recorded in the Vanuatu archipelago in the past 30 years. Centered approximately 90 miles north of Port Vila, the earthquake generated a tsunami which was particularly destructive at the villages of Ena and Vemagely, on the southern tip of Pentecost. Waves, with estimated offshore heights of about 2-3 meters, arrived about half an hour after the earthquake, washing away many of the homes and destroying a church. In some areas, the waves surged two kilometers inland. Ten people died on Pentecost, two were missing, and four were seriously injured by the combined effects of the earthquake and the tsunami. Five of the deaths were attributed to the earthquake and the other five to the tsunami. Most of the deaths occurred at the villages of Ena and Vemagely. About 100 people were injured, most by the earthquake. Thousands of people were left homeless and lost virtually everything in the disaster. There was significant damage to the infrastructure of the country, as landslides blocked roads and communications to some parts in the central and southern parts of Pentecost Island. Water catchment tanks were totally destroyed. Damage also occurred on the islands of Ambryn, Ape and Malacoula. The Vanuatu provinces of Penama and Malempa were declared disaster areas. The tsunami was recorded by numerous tide gauge stations throughout the Pacific. At Vanuatu's Port Vila station, the closest to the earthquake's origin, the gauge recorded tsunami waves of 1.2 m. Peru - Southern - 23 June 2001 A major offshore earthquake (magnitude 8.1) just north of the town of Ocona in Southern Peru, approximately 600 km southeast of Lima and 190 km west of Arequipa, damaged extensively southern Peru - particularly the Arequipa-Moquegua-Tacna area. It generated a local destructive tsunami which struck the coastline - primarily near the epicenter region - approximately 20 minutes after the main earthquake shock. Tsunami waves with runups ranging from 3- 4.5 meters (10 - 15 feet) or more were reported. In some coastal areas, the tsunami waves swept one to two miles inland. According to reports, 2,500 hectares of agricultural land were inundated in Camaná - a popular and picturesque summer resort of around 20,000, some 900 km south of Lima. This was one of the hardest-hit areas by both the earthquake and the tsunami. The tsunami swept more than a half-mile inland over the town and its surrounding rice and sugarcane fields. According to Peru's Civil Defense, at least 20 persons were reported as drowned by the tsunami and another 60 persons as missing. A small tsunami was also observed or recorded at distant locations in the South and Central Pacific and in Japan. 6. THREE STEPS IN REDUCING THE IMPACT OF TSUNAMIS The best tsunami mitigation strategy is to keep people and critical facilities out of the area of potnetial tsunami flooding. To mitigate the impact of tsunamis, it is critical to accurately assess the nature of the threat posed by the hazard, to design and implement a warning technique, and to designate risk areas for appropriate actions. Therefore, three main elements are essential for the development of a tsunami mitigation model: 1) hazard assessment; 2) warning; and 3) preparedness. IOC/ITSU-XVIII/15 page 20 Hazard Assessment: For each coastal community, an assessment of the tsunami hazard is needed to identify populations and properties at risk, and the level of this risk. This assessment requires knowledge of probable tsunami sources, their likelihood of occurrence, and the characteristics of tsunamis from these sources along the coast. The Historical Tsunami Database completed by Russian scientists - now available in computer CD format - provides rapid access and review of past tsunami and earthquake data. The data is displayed in a wide variety of useful graphical formats, and can help quantify tsunami risk factors for coastal communities of member nations. For communities where there is not sufficient historical data to make a reliable forecast of the risk, numerous models of tsunami inundation exist which can provide estimates of areas that will be flooded in the event of a local or distant tsunami. Japanese scientists, with the ICG/ITSU assistance, have developed methodology that can produce inundation maps using numerical models. Warning: The Tsunami Warning System and its centers - described previously - strive to accomplish the following objectives: a) rapidly provide a warning as soon as possible after a potential tsunami has been generated; b) make sure that the warning is accurate and based on reliable information and data; c) operate continuously and that all warnings are sent and received promptly and understood by the users of the system. Preparedness: A state of readiness is essential in mitigating the impact of a potential tsunami. Preparedness by the public precludes: a) knowledge of the warning system and the meaning of its warning messages; and b) knowledge of when and where to evacuate and when it is safe to return. A community-wide awareness effort is essential to educate the residents as to appropriate actions to take in the event of a tsunami. Awareness education includes the creation of tsunami evacuation procedures to remove residents from the tsunami hazard zones, the implementation of an educational program for schools, the coordination of periodic practice drills to maintain readiness level - as it is done in Japan every year on the 1rst of September - and the development of a search and rescue plan. Additional preparedness includes land use planning to locate essential facilities such as schools, police and fire departments and hospitals outside tsunami inundation zones. Engineering efforts in preparedness include the building of tsunami-resistant structures, strengthening and retrofitting existing buildings and, when economically cost-effective, the construction of defensive tsunami barriers such as dikes or breakwaters. The IOC has developed products which can assist countries in implementing tsunami awareness programmes. These are available in both print and electronic forms and include educational materials in different languages, suggested educational curriculums, and videos and reports from communities that have already established comprehensive tsunamis awareness programmes. These educational products are available through ITIC and the IOC Secretariat. 7. IDNDR - LESSONS LEARNED Historical Perspective On 22 December 1989, by resolution 46/182, the Member States of the United Nations proclaimed the 1990s as a the International Decade for Natural Disaster Reduction (IDNDR). The objective of the Decade was to reduce loss of life, property damage and the social and economic disruption associated with natural disasters - including tsunamis. The goal of the Decade was to improve the capability to mitigate the impact of natural disasters, particularly through the use of early warning systems, through proper training and education, through dissemination and application of existing knowledge and information, and through proper IOC/ITSU-XVIII/15 page 21 scientific and engineering research. It was recognized that these goals could only be achieved by the concerted action of nations, and would require international programs of cooperation and assistance to acquire the necessary knowledge and to apply the results. The Decade was established on the basic understanding that sufficient scientific and technical knowledge already exists which, with more extensive application, could save thousands of lives and millions of dollars in property losses from natural disasters. The Decade focused its attention on earthquakes, windstorms, tsunami, floods, landslides, volcanic eruptions, wildfires and insect infestations. An intense and concerted international momentum in disaster mitigation begun worldwide under the auspices of IDNDR – is partly based on input provided by the IOC Tsunami Programme. UNESCO-IOC Tsunami Programme Contribution to the IDNDR Of all the natural disasters, the tsunami disaster has probably received more attention in the mitigation of its effects. This is because - in contrast to other natural disasters which have localized effects - tsunamis have affected adversely the coastal regions of many nations far away from the region of their origin. Moreover, the international cooperative efforts to mitigate the tsunami disaster started in 1965. The tsunami disaster had already been dealt effectively on an international scale years before the Decade had been proclaimed. Thus, IOC' s Tsunami Programme served as an example to the IDNDR effort of how a disaster can be mitigated through international cooperation, an early warning system, concerted research, the sharing of knowledge and information, and by coordinating meetings and educational workshops. The development and usage of hi-tech observations and warning techniques as TREMORS, DART mooring systems developed by the member states of ICG/ITSU, implementation of TIME and HTDB projects and publication of awareness materials, were the IOC contributions to IDNDR. Also, tsunami experts participated in the World Conference on Natural Disaster Reduction, in Yokohama, Japan, 23-27 May 1994, and assisted in the formulation of the Yokohama declaration which consolidated a plan of action for natural disaster reduction for the rest of the Decade, and a strategy for the year 2000 and beyond, at the community, national, regional, sub regional and international level - the latter through similar multilateral cooperation as that achieved by the UNESCO-IOC Tsunami Programme. The declaration identified disaster prevention, mitigation, preparedness and relief to be the four basic elements which are essential to an integrated disaster management system and contribute to lasting improvement in safety, the saving of human lives and the protection of property. Lessons Learned With this historical perspective and overview, the significance of IDNDR cannot be overemphasized. Many lessons were learned. IDNDR clearly showed that natural disasters have become great societal problems, that the costs of these disasters are unbearable in terms of losses in human lives and property, that member states have the ability to manage risks from natural hazards, that long term actions were needed, and that concrete actions for prevention could be taken effectively - the focus placed on disaster preparedness. The success of IDNDR during the last decade of the 20th Century is a matter of public record. The Decade initiated many significant plans of action, and national and international policies for measures which will reduce the adverse___é impact of natural hazards in the new millennium. The end of the Decade was not the end of initiatives the IDNDR begun. There is still work to be done in evaluating progress made, identifying remaining needs, and making appropriate recommendations to national and international organizations for the implementation of plans for future action. IDNDR is over but it has left many opportunities and challenges for future international disaster mitigation efforts. By establishing national committees and IOC/ITSU-XVIII/15 page 22 appropriate infrastructure, IDNDR has provided further impetus for international cooperation - with additional benefits to the Tsunami Programme.__ In 1999, the UN General Assembly took a decision regarding the post-IDNDR strategy for disaster reduction. A new UN mechanism was established to coordinate the efforts of international agencies and Member States in enabling communities to become resilient to natural hazards. The International Strategy and Disaster Reduction (ISDR) was formulated and an Inter-Agency Secretariat was established. The IOC Tsunami Programme is evaluating progress made during the Decade, is identifying remaining needs, and is making appropriate recommendations to national and international organizations for the implementation of future action. This is particularly important in view of the fact that - as the Decade came to its end with the beginning of the new millennium - the threat of tsunami impacts upon mankind with relentless severity and frequency. The end of IDNDR presented a unique opportunity and a challenge to contribute significantly to plans of action and national and international measures which will reduce the adverse impact of tsunamis in the new millennium. More than anything, the recent, destructive tsunami disasters in countries such as Indonesia, Vanuatu, Papua - New Guinea, Nicaragua, Peru and elsewhere, emphasize the need to further embrace the IDNDR initiatives on disaster mitigation and to continue the work by focusing attention on the developing countries - which experience losses in human lives and economy disproportionate to their resources. 8. THE TSUNAMI PROGRAMME IN THE NEW MILLENNIUM - TAMING THE KILLER WAVES The historic record shows that 482 tsunamis occurred during the 20th century and that at least 133 of these had heights greater than 1.5 meters. In the last twenty years there has been rapid growth in populations and in development throughout the world. Much of this growth has taken place in vulnerable coastal areas, along seismically active zones. As a result, the adverse effects of tsunami disasters has been greater than in the past. In the last ten years, in spite of vigilance and early warning systems, thousands of lives were lost. Technologic and economic developments have made the use of coastal zones more necessary than before. In spite of lessons learned from IDNDR and the UNESCO-IOC- coordinated mitigation efforts, losses from tsunami disasters will continue to occur again and again in the 21st Century. A major Pacific-wide tsunami is likely to occur in the near future. Numerous, locally generated tsunamis can be expected. As the 1998 PNG tsunami demonstrated clearly, many countries in vulnerable areas are not prepared for such disasters, while others have let their guard down. Major tsunami disasters are expected to result in complex humanitarian emergencies that will compromise seriously the socioeconomic development of vulnerable countries and. will create escalating demands on rapidly diminishing international resources. Therefore, the social and economic impact of future tsunamis cannot be overlooked. The IOC Tsunami Programme faces new challenges in mitigating the impact of future tsunamis. Future Mitigation Efforts Nothing can be done to prevent the occurrence of tsunamis. Although tsunamis cannot be prevented, the adverse impact on loss of life and property can be reduced with proper planning. Most efforts of the Tsunami Programme have concentrated in the Pacific Ocean where the frequency of this hazard has been high. However, the record shows that destructive tsunamis have been generated also in the Atlantic and Indian Oceans and in the Caribbean and IOC/ITSU-XVIII/15 page 23 Mediterranean Seas. Therefore, no matter how remote, the likelihood of a tsunami should be considered in developing coastal zone management and land use - anywhere in the world. Countries with vulnerable coastlines are faced with the continuous challenge of mitigating the effects of future tsunami disasters. Mitigation efforts will not tame the tsunami killer waves but, certainly, can rob them of their adverse impact by reducing the vulnerability of coastal populations. Future efforts by IOC and ITSU member nations emphasize programmes of preparedness and public education on the tsunami hazard and on public safety, not only for the Pacific region but for other vulnerable areas around the world. 9. ADDITIONAL STEPS IN TSUNAMI DISASTER REDUCTION Planning New advances in the science and technology of hazard mitigation provide the means for reducing losses, particularly those due to locally generated tsunamis - for which there is no sufficient time for warning. For example, loss of life and damage to property can be minimized through improved communications, land use planning, preparation, and quick and proper evacuation. Since, tsunamis tend to impact the same localities over and over again, one alternative is to avoid living in or using areas with significant tsunami risk. In the coming years, the IOC Tsunami Programme will continue to encourage national government agencies to formulate land-use regulations for coastal areas with the tsunami risk potential in mind, particularly if such areas are known to have sustained damage in the past. The Programme will continue to encourage national agencies to look for alternative areas that are safer. The Programme will continue its outreach, particularly to developing countries, emphasizing to local national authorities the need to review land use in vulnerable coastal areas so that no critical facilities, such as hospitals, schools, petroleum-storage tanks, are located where there is potential tsunami danger. Increasing Tsunami Hazard perception by the public Another goal of the IOC Tsunami Programme is to improve the tsunami hazard perception by the people living in vulnerable coastal areas. Over warning, based on inadequate knowledge of the phenomenon or inadequate data on which to base the prediction, often leads to false alarms and lack of compliance with warning and evacuation attempts. Such false alarms result in a loss of faith in the capability of the system and result in reluctance to take action in subsequent tsunami events. Even if a tsunami prediction is based on valid information and data, warning and evacuation may not be sufficient to minimize the impact of tsunami on coastal populations. Hazard perception by the public is based on an understanding of the phenomenon, at least at the basic level, and a behavioural response stemming from this understanding__ and from confidence of the public in the warning authorities. Fortunately, forecasting tsunamis in recent years has been quite good and the image of the Tsunami Warning System and its credibility have improved considerably. Forecasting, however, is not an exact science as the phenomenon itself is very complex. Data on which the forecast is based may often be inadequate for certain areas. The IOC Tsunami Programme will continue to identify such areas and, through the ITSU membership, promote additional programmes of public education. Enhancing Awareness through public education Public education is indeed the most important aspect of mitigation efforts. Only through a comprehensive education programme, a heightened community awareness of the potential IOC/ITSU-XVIII/15 page 24 threat of tsunami can be achieved. Civil defense authorities in each ITSU member country are encouraged to conduct public education programme consisting of seminars and workshops for responsible government officials, to publish informational booklets on the hazards of tsunami, and to coordinate with the communications media the announcement of tsunami information. The IOC Tsunami Programme encourages other governmental and non-governmental agencies and institutions to take actions in mitigating future tsunami losses. For example, the Programme encourages government agencies to develop sound coastal management policies, which include zoning and planning for tsunami-prone coastal areas. Scientific organizations can undertake research and engineering studies in developing evacuation zones or engineering guidelines for building coastal structures. Audiovisual materials can be prepared for educating children in schools and the public in general. Brochures and pamphlets can be printed describing the tsunami warning system and what the public can do in time of tsunami warning. Internally, government agencies can streamline and coordinate their operating procedures and communications so they can perform efficiently when the tsunami threat arises. Procedures related to tsunami warnings should be reviewed frequently to define and determine better respective responsibilities between the different government agencies at all levels. Future challenges in tsunami disaster reduction In spite of technological improvements of the last two decades, the Tsunami Warning System is still unable to provide timely warnings to many areas of the Pacific and none to other parts of the world. Improvements are necessary in communications to ensure that warning information is prompt and accurate. An increased degree of automation is necessary in handling and interpreting the basic data. For example, further research in the development of deep-ocean sensors could be useful in early tsunami detection. Research in the real-time interpretation of seismic source parameters, may help in tsunami evaluation and the issuance of prompt warnings. More research is needed in improving the understanding of tsunami interaction with the coast. Concerted research efforts in ITSU member states can also lead to improvement of warning systems, to better land-use management of tsunami-prone coastal areas and to the development of important engineering guidelines for critical coastal structures. The long-term objective of the IOC Tsunami Programme is to build up the technical and scientific infrastructures in each ITSU member country, so as to deal effectively with future tsunami threats. The immediate objectives in each ITSU country is to assess the tsunami hazard in terms of potential needs and available resources. Preparedness requires several capabilities, such as rapid identification of imminent tsunami, effective national and regional warning systems to alert coastal population and industries, and civil defense and community preparedness to respond to tsunami warnings. Finally, the goal of the IOC Tsunami Programmed is to develop in each ITSU member nation the appropriate improvements in warning capability, in the form of improved instrumentation for tsunami monitoring and for communications - both for effective warning and for increased knowledge as an aid to long-term protection. In summary, and in order for a tsunami warning to be of value, the IOC Tsunami Programme promotes the improvement of an expeditious and effective international communications system, which must be vigilantly maintained to insure proper dissemination throughout a large geographical area. Civil Defense authorities in each ITSU member country, collaborating into the Tsunami Warning System, are encouraged to have good emergency operating plans for their own territories, efficient internal communications, and a program of tsunami preparedness which includes organizational infra structural coordination and comprehensive public education. IOC/ITSU-XVIII/15 page 25 10. PREPAREDNESS - WHAT DO YOU NEED TO KNOW & DO TO SAVE YOUR LIFE Sooner or later, tsunamis visit every coastline in the Pacific and in other world oceans and seas. All tsunamis are potentially dangerous even though they may not damage every coastline they strike. The occurrence of tsunamis cannot be prevented but with proper planning, preparedness and warning information, loss of life and property can be reduced. People who live on the coast, particularly in areas known to have sustained tsunami damage in the past, should memorize the following facts and basic safety rules: Tsunami Safety Rules Not all large earthquakes generate tsunamis, but many do. If the earthquake is located near or directly under the ocean, the possibility of a tsunami is greater. If you live in a low-lying coastal area and you feel the ground motions of a strong earthquake, this is a natural warning signal of possible immediate danger from a tsunami. Dangerous tsunami waves may be imminent or coming in a few minutes. Protect yourself from the earthquake first and when its ground motions cease, move quickly inland away from the coast or to higher ground. Try to evacuate to a safe zone that is at least 15 meters (50 feet) or more above sea level. Approaching tsunamis are sometimes preceded by a noticeable rise or fall of coastal water. This is nature's warning that a tsunami is approaching. Stay away from the beach and quickly evacuate to higher ground. Never go down to the beach to watch for a tsunami. When you can see a tsunami wave, you are too close to escape. If you do not feel the strong ground motions of an earthquake but you hear that an earthquake has occurred in the ocean or coastline region and receive a tsunami warning, follow instructions carefully. Prepare for a tsunami emergency and for evacuation to higher ground. The historical record shows that when the great waves strike, they claim the lives of those who ignored the tsunami warning. Remember that a tsunami is not a single wave, but a series of waves that may be dangerous and destructive. The first wave is not necessarily the largest. A small tsunami at one beach can be a giant a few miles away. Don't let the modest size of one wave make you lose respect for all. Additional large waves may be coming and the danger may continue for several hours. During a tsunami emergency, your local emergency management office,___ª police, and other emergency organizations will try to protect your life. Give them your fullest cooperation. Stay tuned to your radio, marine radio, Weather Radio, or television stations during a tsunami emergency. The Bulletins which are issued through your local emergency management office could save your life. Stay out of dangerous coastal areas until a tsunami warning cancellation is issued by a qualified warning authority. What you can do Before, During and After a Tsunami Strikes Like with any natural disaster, knowledge of the tsunami risk and preparedness could make the difference between surviving or getting killed or injured when a tsunami strikes your coastal community. For information on tsunamis and the assessment of risk in your area, contact your local emergency management office. Additionally, there are many things you can do to protect yourself and your family before, during and after a tsunami disaster strikes. It is important for all your family members to know IOC/ITSU-XVIII/15 page 26 how to respond to a tsunami warning and to be familiar with an evacuation plan and routes to safe areas. Before : Determine if your home is in a tsunami danger area. Know the height of your street above sea level and the distance of your street from the coast. If a tsunami is imminent or a warning is issued, evacuation orders may be based on these numbers. Familiarize yourself and family members with the tsunami warning signs and make sure that they understand how to respond to a tsunami. Each family member should know how and when to turn off utilities such as gas, electricity, and water. Children should be taught how and when to call the police or the fire department and which radio station to listen for official information and instructions. Every effort should be made to store and have access to disaster supplies. These should include flashlights, a portable, battery-operated radio, extra batteries, a first aid kit, essential medicines, emergency food and water, a non-electric can opener, clothing, cash and credit cards. Make evacuation plans: Pick an inland location that is elevated. Roads in and out of the coastal area may be blocked by excessive traffic, so pick alternate evacuation routes. In case family members are separated from one another during a tsunami (a real possibility during the day when adults are at work and children are at school), develop an emergency communication plan for getting back together. Ask an out-of-state relative or friend to serve as the "family contact." After a disaster strikes, often it is easier to call long distance. Make sure everyone knows the name, address, and phone number of the contact person. During: A tsunami warning is issued only when authorities are certain that a tsunami threat exists for your coastal community. In some vulnerable coastal regions, civil defense authorities have installed special sirens that sound off when a tsunami warning is issued. If you detect on your own any of the telltale signs of an imminent tsunami as explained previously, evacuate at once by climbing to higher ground or moving inland. If you hear an official tsunami warning, or hear a siren, immediately turn your radio or television on and listen for the latest emergency information. This may include expected arrival time of the tsunami, predicted height range, safe areas to evacuate, location of shelters established by emergency response authorities. Listen carefully to the instructions given and be ready to evacuate if asked to do so. Don't wait too long to evacuate and do not stay near the beach to watch the tsunami come in. As mentioned earlier, if you can see the wave you are too close to escape it. Return home only after authorities advise it is safe to do so. As explained previously, a tsunami is a series of waves and the danger may last for hours. After: A tsunami warning may be in effect for several hours. Stay tuned to a battery- operated radio for the latest emergency information. Remember to help your neighbors who may require special assistance - infants, elderly people, and people with disabilities. Help the injured or trapped persons first. Give first aid where appropriate. Do not move the seriously injured persons unless they are in immediate danger of further injury. Immediately call for help. Stay out of damaged buildings. Return home only when authorities say it is safe. Enter your home with caution. Use a flashlight when entering damaged buildings. Check for electrical shorts and live wires. Do not use appliances or lights until an electrician has checked the electrical system. Open windows and doors to help dry the building. Shovel mud while it is still moist to give walls and floors an opportunity to dry. Check food supplies and test the drinking water. Fresh food that has come in contact with floodwaters may be contaminated and should be thrown out. Have tap water tested by the local health department. IOC/ITSU-XVIII/15 page 27 Inspecting your Home after its damage by a Tsunami Check for gas leaks: If you smell gas or hear a blowing or hissing noise, open a window and quickly leave the building. Turn off the gas at the outside main valve if you can and call the gas company from a neighbor's home. If you turn off the gas for any reason, it must be turned back on by a professional. Look for electrical system damage - If you see sparks or broken or frayed wires, or if you smell hot insulation, turn off the electricity at the main fuse box or circuit breaker. If you have to step in water to get to the fuse box or circuit breaker, call an electrician first for advice. Check for sewage and water lines damage - If you suspect that the sewage lines are damaged, avoid using toilets and call a plumber. If the water pipes are damaged, contact the water company and avoid the water from the tap. You can obtain safe water for drinking by melting ice cubes. Overall Tsunami Mitigation Efforts - What More You Should Know and Do Mitigation efforts include any activities that can prevent or reduce the direct damaging effects of a tsunami and avoid secondary emergencies after the disaster strikes. For example, if you live near the shore, you can check with civil defense authorities to learn if tsunami inundation studies have been conducted in your region which would indicate whether or not you live in a safe coastal zone. You can also check the local building codes and ordinances to make sure that your home is properly built. You may be able to reduce the damaging impact of a tsunami in the future by strengthening the structural integrity of your house with simple reinforcements. If a destructive tsunami strikes you area, there may be no electricity or water for the first few days. There may be food shortages. Prepare for these contingencies by assembling food, supplies and money in a backpack to last at least 2-3 days after a tsunami strikes your area. Finally, contact your local emergency management office for additional information on tsunami mitigation, for safe zones to evacuate and for the location of shelters where tents and feeding facilities may be located. 11. USEFUL ADDRESSES AND INTERNET LINKS UNESCO-IOC UNESCO - IOC - International Coordination Group for the Tsunami Warning System in the Pacific (ICG-ITSU) http://www.gsf.de/UNEP/itsu.html http://ioc.unesco.org/iocweb/ International Tsunami Information Centre (ITIC) http://tgsv5.nws.noaa.gov/pr/hq/itic.htm http://www.nws.noaa.gov:80/pr/os/ITIC.HTM ITIC Newsletter On-Line http://www.shoa.cl/oceano/itic/newsletter.html http://www.shoa.cl/oceano/itic/frontpage.html IOC/ITSU-XVIII/15 page 28 NATIONAL AND INTERNATIONAL TSUNAMI WARNING CENTERS - TSUNAMI WARNING PLANS Canada - British Columbia Tsunami Warning Plan http://hoshi.cic.sfu.ca/~pep/tsunami.html Japan - Japan Meteorological Agency http://www.kishou.go.jp/english/activities/earthquake/earthquake.html Pacific Tsunami Warning Center http://www.nws.noaa.gov/pr/ptwc/ Russia - Sakhalin Tsunami Warning Center http://www.science.sakhalin.ru/tsunami/ USA - Alaska Tsunami Warning Center (For West Coast USA-Canada) http://wcatwc.gov/ Alaska Tsunami Warning System http://www.alaska.net/~atwc Tide Networks with Real Time Telemetry. ATWC network: http://wcatwc.gov/subpage2.htm GENERAL TSUNAMI INFORMATION / HISTORICAL DATA Dr. George Pararas-Carayannis - Tsunami Page http://www.geocities. com/drgeorgepc http://www.geocities. com/CapeCanaveral/ Lab/1029 The Effects of Tsunami on Society http://www.geocities.com/CapeCanaveral/Lab/1029/TsunamiImpactSociety.html L' Incidence des Tsunami sur la Société http://www.geocities.com/CapeCanaveral/Lab/1029/TsunamiImpactSociete.html FEMA (Federal Emergency Management Agency - USA)- Tsunami Fact Sheet http://www.fema.gov/fema/fact10.html NASA - Tsunami - The Great Wave http://observe.ivv.nasa.gov/nasa/exhibits/tsunami/tsun_bay.html National Geophysical Data Center (NGDC - NOAA) Tsunami Database, Boulder, Colorado, http://www.ngdc.noaa.gov/seg/hazard/tsu.html National Weather Service (NWS - USA): Tsunami: The Great Waves http://www.nws.noaa.gov/om/tsunami.htm Pacific Tsunami Museum http://planet.hawaii.com/TSUNAMI PMEL Tsunami Project (NOAA) IOC/ITSU-XVIII/15 page 29 http://www.pmel.noaa.gov/tsunami/ University of Washington (Seattle) -Tsunami! http://www.geophys.washington.edu/tsunami/welcome.html OTHER INTERESTING TSUNAMI WEB SITES (Governmental and Non-Governmental) Russia - Novosibirsk Tsunami Laboratory, Computing Center of the Russian Academy of Sciences, Siberian Branch, Novosibirsk, Russia http://omzg.sscc.ru/tsulab/ USA - National Geophysical Data Center (NGDC) Tsunami Database, Boulder, Colorado, http://www.ngdc.noaa.gov/seg/hazard/tsu.html NOAA, Pacific Marine Environmental Laboratory, Seattle: Tsunami Project http://www.pmel.noaa.gov/tsunami/ PMEL/NOAA network: http://tsunami.pmel.noaa.gov/dartqc/WaveWatcher The National Tsunami Hazard Mitigation Program http://www.pmel.noaa.gov/tsu__nami-hazard/ NOAA- Tsunami Hazard Reduction http://www.cop.noaa.gov/projects/tsunami.html Federal Emergency Management Agency (FEMA): Fact sheet on Tsunamis http://www.fema.gov/library/tsunamif.htm U.S Geological Survey (USGS)Tsunamis and Earthquakes - tsunami research. http://walrus.wr.usgs.gov/tsunami/ ACADEMIC WEB SITES Australia - Macquarie University. Australasian Hazards Research Directory - Natural Hazards Research Centre. (Research in the Australia - South Pacific region and a profile of efforts on the world scene. Flinders University: http://www.ntf.flinders.edu.au/TEXT/PRJS/NRTM/nrtm.html Japan - Tohoku University Tsunami Research Group, Sendai http://www.tsunami.civil.tohoku.ac.jp/ Mexico - CICESE Spanish Language Tsunami Page http://www.cicese.mx/ USA - University of Southern California - Tsunami http://cwis.usc.edu/dept/tsunamis/ TSUNAMI FIELD SURVEY PHOTOGRAPHS IOC/ITSU-XVIII/15 page 30 http://cwis.usc.edu/dept/tsunamis/home.html University of Washington, Seattle: Tsunami http://www.geophys.washington.edu/tsunami/welcome.html Tsunami, The Great Waves http://tsunami.ce.washington.edu/tsunami/general/warning/reference.html http://tsunami.ce.washington.edu/tsunami/general/warning/warning.html University of Hawaii (Meteorology) http://lumahai.soest.hawaii.edu/tsunami.html Tsunami Messages http://lumahai.soest.hawaii.edu/tsunami.html University of Southern California, Los-Angeles, USA http://cwis.usc.edu/dept/tsunamis/ Cornell University - Tsunami animations http://www.tc.cornell.edu/~devine/tsunami.html University of Colorado, Boulder. The Natural Hazards Center. University of Virginia http://www.lib.virginia.edu/sdc/HAZARD/Tsunami/ 12. LIST OF IOC PUBLICATIONS RELATED TO TSUNAMI HAZARD MITIGATION ALASKA "TSUNAMI! THE GREAT WAVES IN ALASKA" Brochure from the Alaska Division of Emergency Services. BRITISH COLUMBIA "BRITISH COLUMBIA TSUNAMI WARNING AND ALERTING PLAN (2001)" This off- site web document explains (from a state/province perspective) the protocols and procedures in place for Pacific-wide tsunami warning and alerting; advises areas at risk; and assigns responsibilities. Adobe Acrobat files. "PREPARE FOR A TSUNAMI IN COASTAL BRITISH COLUMBIA" Public awareness document for citizens of coastal British Columbia communities. Also available in Adobe Acrobat format "as printed". "EFFECTS OF THE TSUNAMI IN THE ALBERNI INLET CAUSED BY THE 1964 ALASKA EARTHQUAKE" (All pictures) From the British Columbia Provincial Emergency Program (PEP). IOC/ITSU-XVIII/15 page 31 CALIFORNIA "TSUNAMI! HOW TO SURVIVE THE HAZARD ON CALIFORNIA'S COAST" Brochure from the State of California. "LIVING ON SHAKY GROUND: HOW TO SURVIVE EARTHQUAKES AND TSUNAMIS ON THE NORTH COAST" An earthquake awareness publication for the Northern California coast, and which includes a tsunami awareness section; from Humboldt State University. HAWAII "TSUNAMI: THE GREAT WAVES" A well-illustrated document to increase awareness and knowledge of tsunamis. Produced with the cooperation of the IOC, NOAA and ITIC. "TSUNAMI WARNING" A publication designed to inform young persons about tsunamis and the dangers which they present, and what should be done to save lives and property "TSUNAMI WARNING SYSTEM IN THE PACIFIC" A short brochure describing the system. OREGON "TSUNAMI! HOW TO SURVIVE THIS HAZARD ON THE OREGON COAST" Brochure from the State of Oregon. WASHINGTON "Tsunamis on the Pacific Coast of Washington State and Adjacent Areas - an Annotated Bibliography and Directory” U.S. National Aeronautical and Space Administration From the NASA "Observatorium": Tsunami- The Big Wave U.S. Federal Emergency Management Agency Tsunami Fact Sheet (.html) and (Adobe .pdf) U.S. National Oceanic and Atmospheric Administration, Pacific Marine Environmental Laboratory Tsunami Hazard Mitigation: A Report to the Senate Appropriations Committee. National Geophysical Data Center Boulder, Colorado USA Tsunami Database; Tsunami Slide Sets; Tsunami Publications The International Journal of The Tsunami Society Science of Tsunami Hazards Journal IOC/ITSU-XVIII/15 page 32 Eos Vol. 75, No. 1, January 4, 1994, p. 3. © 1994 American Geophysical Union. "Study of Recent Tsunamis Sheds Light on Earthquakes" by Kenji Satake, Department of Geological Sciences, University of Michigan, Ann Arbor List of Tsunami Research Papers: List of "earthquakes" (Year Region) that have Tsunami studies CICESE (Mexico) " Tsunami (maremoto) ". In Spanish; web-based version of a brochure published by Centro de Investigacisn Cientmfica y de Educacisn Superior de Ensenada (CICESE).
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