EARTHQUAKES AND VOLCANOES - UNDERESTIMATED HAZARDS by xab70192

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									                                                                                       November 1, 2005
                                                                                          Vol. 54, No. 22
                                                                                               Telephone 971/673-1111
                                                                                              Emergencies 503/731-4030
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                                                                                                cd.summary@state.or.us
                                                                                 http://oregon.gov/DHS/ph/cdsummary/

     AN EPIDEMIOLOGY PUBLICATION OF THE OREGON DEPARTMENT OF HUMAN SERVICES

                 EARTHQUAKES AND VOLCANOES – UNDERESTIMATED HAZARDS



W
          HILE  hurricanes and tsu-     to the east could be affected by ash-   quakes were in Portland, Mt. Hood,
            namis may seem distant      falls disrupting transportation and     Lakeview, Klamath Falls, Newport,
            hazards, scientists warn    water supplies, and causing signifi-    Adel, Canby, Maupin, Woodburn,
that earthquakes and volcanic           cant air quality concerns for those     Christmas Valley, and Scotts Mills.
eruptions are real and not easily       with respiratory problems.              Epicenters are the surface focus
predictable dangers to Oregonians.      EARTHQUAKES                             point of an earthquake—the result-
This issue of the CD Summary               The intensity of earthquakes is      ing seismicity and damage radiates
reviews the potential for natural       measured using the logrithmic Rich-     out from epicenters, factored by the
disasters due to earthquake and         ter Scale, which ranges from zero to    magnitude of the quake. Damage
volcanic activity in Oregon and         10. The San Francisco earthquake of     and injury can occur in areas far
offers some recommendations for         1906 is estimated to have been a        from the epicenter.
preparedness that you canhelp           magnitude 7.9 quake, and the recent        In 2000 an international group of
with as a healthcare provider.          earthquake in Pakistan is estimated     scientists released the first consen-
VOLCANIC ERUPTIONS                      to have been a magnitude 7.6.           sus paper on the likelihood, power,
   In 1806, Meriwether Lewis and           Damaging earthquakes in the          and resulting damage from an
William Clark named a river on          Northwest can arise from three          earthquake in the Cascadia subduc-
the south side of the Columbia          source zones: the Cascadia subduc-      tion zone lying 30-70 miles off the
River gorge the “Quicksand River.”      tion zone, the Juan de Fuca oceanic     Oregon coast. The Oregon Depart-
The wide, shallow river with a bed      plate, and the North American con-      ment of Geology and Mineral Indus-
“formed entirely of quicksand,”         tinental plate. Many Oregonians         tries estimates a 10–15 percent
bears little resemblance to the         may not be aware that, since 1993,      chance of a magnitude 9 quake in
narrow, moderately deep river we        24 notable quakes ranging in magni-     the next 50 years. An earthquake off
call the Sandy River today. What        tude from 2.7 – 6.3 have occurred in    Oregon’s coast could shake the
happened? The answer lies 50            Oregon. The epicenters of these         ground as far east as the Cascades
miles away on Mount Hood. An                 Diagram of Subduction Zone         obliterating thousands of buildings
eruption in the 1790’s caused a                                                 and isolating communities for days
tremendous amount of volcanic                                                   or longer, particularly those on the
rock and sand to enter the Sandy                                                Coast.
River drainage.                                                                    Aftershocks would likely be nu-
   Someday Mount Hood will erupt                                                merous and exceed magnitudes of
again. Scientists expect small explo-                                           7.5. Shaking is likely to occur for 1-3
sions, and the growth and collapse                                              minutes at magnitude 8. Liquefac-
of lava domes, generating pyroclas-                                             tion (a phenomenon in which the
tic flows (high speed avalanches                                                strength and stiffness of a soil is
containing hot rock, gas, and ash                                               reduced by earthquake—responsi-
that lethally burn or asphyxiate all                                            ble for tremendous amounts of
in their paths), ash clouds, and                                                damage in earthquakes) and land-
lahars (fast moving slurries of rock,                                           slides would accompany this type
mud, and water formed when py-                                                  of quake. Tsunamis would occur on
roclastic flows melt ice or snow                                                coastlines. Maximum wave run-up
that move down river valleys and                                                heights may reach close to 36 feet.
bury, move or smash objects in                                                  Wave activity may start within
their paths). Lava flows and pyro-                                              minutes of the quake and will per-
clastic flows rarely travel more                                                sist for several hours.
than eight miles but the heat gener-                                            MORBIDITY AND MORTALITY
ated can cause lahars that devas-                                                  Experience with natural disasters
tate populated river valleys in their                                           suggests that most morbidity and
path. Portland and sites downwind                                               mortality after an earthquake or a
The CD Summary (ISSN 0744-7035) is published biweekly, free of charge,       CD SUMMARY                                          PERIODICALS
by the Oregon Dept. of Human Services, Office of Communicable Disease
and Epidemiology, 800 NE Oregon St., Portland, OR 97232                      November 1, 2005                                     POSTAGE
Periodicals postage paid at Portland, Oregon.
Postmaster—send address changes to:                                          Vol. 54, No. 22                                         PAID
CD Summary, 800 NE Oregon St., Suite 730, Portland, OR 97232                                                                     Portland, Oregon




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  volcanic eruption would be due to                          fractures, dislocations, asphyxia,        evacuees. However, a provider is
  injuries. A 1999 preliminary state-                        traumatic brain injury, lacerations,      likely to be able to fulfill those
  wide assessment reported that 5,000                        exposure, penetrating foreign body        roles only if he or she is comfort-
  Oregonians would die after a seri-                         injuries, internal organ injuries, and    able that loved ones are safe and
  ous earthquake. For every death, as                        inhalation of gas, smoke or dust.         cared for. As critical service pro-
  many as three persons would re-                            PREPAREDNESS                              viders it will be especially impor-
  quire hospitalization, and ten per-                           Health care providers can help         tant to make sure your family is
  sons would be treated in emergency                         educate patients about the need for       prepared.
  rooms and released.                                        preparedness, facilitate medical care        Healthcare providers also can
     In the event of an earthquake or                        for those with chronic diseases and       be important advocates for emer-
  volcanic eruption, Oregonians                              the injured, and advocate for commu-      gency preparedness in the com-
  could experience flash flooding,                           nity preparedness to save lives.          munity. Among other activities,
  building collapse, landslides, bridge                         The first steps towards prepared-      healthcare providers can lend
  collapse, electrical hazards, stress,                      ness involve understanding that we        their support to community ef-
  exertion, exposure to the elements                         are at risk. Unlike our brethren in the   forts to retrofit buildings to reduce
  and exposure to sharp or otherwise                         Southeast, Oregonians do not experi-      earthquake damage, ensure a
  hazardous debris. Leading causes of                        ence an annual season of natural di-      strong EMS and trauma care sys-
  death are likely to include drown-                         sasters, and because of the low           tem that is prepared to function in
  ing, cardiac events, multiple trau-                        number of earthquakes and volcanic        a disaster, and assist in the devel-
  ma, hypothermia, internal injuries,                        eruptions, Oregonians may not per-        opment of local hospital emergen-
  and brain injuries.                                        ceive that they are at real risk.         cy preparedness plans.
     Causes of morbidity are likely to                          Once a disaster has occurred health       For additional information on
  include electrocutions, burns, punc-                       care providers will be important          preparedness contact Nan Newell,
  ture wounds, strains/sprains to the                        providers of emergency care, as well      Ph.D., Manager, Oregon Public
  back and neck, soft tissue injuries,                       as health care in shelters or among       Health Preparedness at (971) 673-
                                                                                                       1314 or nanette.newell@state.or.us
         What healthcare providers can do:                                                             ONLINE RESOURCES
         • Identify critical medication needs and make sure that patients have an adequate                Oregon’s official tsunami web-
             supply on hand in case of a disaster.
         • Counsel patients to plan what they and their families will do if a disaster occurs.
                                                                                                       site. www.oregongeology.com/earth-
                                                                                                       quakes/coastal/tsubrochures.htm
         What patients can do:                                                                            Earthquake and tsunami evacu-
         • Create emergency kits for home, work, and each car with enough supplies, including          ation route for Oregon coast.
             food, water and necessary medication, for each member of the family to survive for        www.oregon.gov/OOHS/OEM/
             three days.
         • Make plans for evacuation, including moving pets and medically vulnerable or socially       tsunami.shtml
             isolated family members.                                                                     Tsunami hazard awareness
         • Involve someone not likely to be affected by a disaster occurring in Oregon in a            materials. www.pmel.noaa.gov/tsuna-
             communication plan to help people stay in touch.                                          mi-hazard/tsunami_awareness.htm
         • Store a copy of important documents, including passports, drivers licenses, bank
             account numbers and insurance information in a safe place so that it can be quickly          “Put together an emergency
             and easily accessed.                                                                      kit”. http://sarvis.dogami.state.or.us/
                                                                                                       emergencykit.htm

								
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