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Tsunami
M.L. Anderson, 2009
Tsunami: Giant sea waves
Usually produced by
earthquakes but can also be
caused by submarine landslides
or volcanic eruptions.
Anchorage: Earthquake &
Tsunami Damage
Sudden Tsunami
movements of the
sea floor, which set
off waves within the
water that travel
outward.
They are commonly
not felt in the open
ocean, however, wh
en the tsunami
approaches
shorelines, the
waves slow down
and water piles up to
heights over 65m.
Tsunami or Seismic Sea Wave
Long wavelengths (> 200 km or 125 m)
Shallow-water wave
Speed proportional to water depth so very fast
in open ocean
Sea level can rise up to 40 m (131 ft) when
tsunami reaches shore
Earthquake Prediction
PTWS: Pacific Tsunami
Warning System.
A network of stations that
attempt to identify
potentially damaging
tsunamis from
earthquakes in or around
the Pacific Ocean.
Issues early warnings
especially in Hawaii and
Japan.
Tsunami Warning
System
Tsunami Types and Triggers
Landslide
Earthquake Triggered
Submarine Landslide
Volcanic Eruption
Undersea Mega-thrust Earthquake
Landslide Triggered Tsunami
Informative kinematics specify
position, velocity, and thickness of material
that transcends down-slope.
With slide shape
and thickness,
we are able to
compute tsunami
waves.
Landslides Triggered Tsunami
On July 17, 1998, an earthquake
generated one of the most
destructive tsunamis.
The earthquake triggered a
massive underwater landslide.
As a result, people drowned
and villages were
destroyed.
•2,183 People Died
•Most of the victims were
children.
•Thousands Injured
•Several Villages completely
destroyed
The Trigger
7.0 Magnitude Earthquake
Caused Landslide which in turn
caused Tsunami.
4 waves
Lasted 18 minutes
30 ft high waves
Earthquake occurred at 6:49pm
http://www.drgeorgepc.com/Tsunami1998PNG.html 6:50pm waves hit the shore
http://www.briancasseyphotographer.com/images/awards/10.jpg
Location of Papua, New Guinea
1. The smaller Caroline plate
forces the Australian plate up.
2. Occurred along a steep
dipping reverse fault
Papua/ New Guinea Faults
New Guinea is the site of
an arc-continent region
where tectonic plates
slide or converge past
each other.
The tectonic
boundaries and
faulting are complex in
this region.
walrus.wr.usgs.gov/tsunami/PNG.html)
This diagram shows the boundaries
and faults in New Guinea.
Bathymetry
There is a very steep
and linear slope
located off of the
northern shore of
New Guinea.
This slope could have
been a factor for the
unusual height of the
tsunami that was
caused by the
earthquake.
July 17, 1998 6:49 PM
Minutes after the occurrence of the earthquake, four
successive tsunami waves hit the coast of Papua/New Guinea.
As a result, two villages disappeared and two other villages
were destroyed. Trees were ripped out of the ground due to
the movement of the waves.
Tsunami Waves
People had no choice, but to run
when they saw the tsunami
waves.
There were four tsunami waves.
The travel time of the first
tsunami wave was one
minute.
The four tsunami waves
occurred within a total time
of eighteen minutes.
Each tsunami wave was
short.
Each tsunami wave
averaged to about four
minutes long.
Canary Islands; La Palma
Landslide Tsunami
Cumbre Vieja (Spanish: "Old
Ridge") is an active volcanic
ridge on the volcanic ocean
island of Isla de La Palma in
the Canary Islands. Location:
Spain.
This ridge trends in an
approximate north-south
direction and covers the
southern third of the island. It is
lined by several volcanic
craters.
La Palma landscape
La Palma
The La Palma
landslide slide
will involved 500
km3 of material
running out to 60
km at a mean
speed of 100 m/s.
Not if…but when?
Landslide & tsunami
Sub oceanic landslides are similar to
ground landslides, since this involves
movement of rock and sediment.
Differences between the ground and
sub oceanic water is its degree of
steepness.
Ground inclinations of ~10o are at
odds and sea floors of slight
inclinations of <~1o are also at risk.
Earthquake Triggered Tsunamis
1755
Lisbon, Portu
gal
A near 9.0 magnitude earthquake occurred 200 km from the
Portuguese coast.
This earthquake was generated by convergence between the
African and Eurasian Plates at a ridge known as Gorringe Bank.
The earthquake itself destroyed much of the Portuguese City of
Lisbon.
Lisbon
Earthquake/
Tsunami
Several minutes after the earthquake, a minimum of 3 tsunamis,
around 10 meters in height, ravaged the city.
The waves also hit Spain and North Africa, and did damage in the
Azores, Madiera, and the Canary Islands.
Its effects were felt as far west as the Caribbean Islands, where 3-5
meter waves were reported, and as far north as Ireland.
Submarine Landslide &
Earthquake Triggered Tsunami
Grand Banks 1929
Puerto Rico 1918
San Pedro, Calif. Pending
Santa Barbara, Calif. Pending
Algunas, So. Africa 1.8Myo
Submarine
Landslides
The largest landslides on Earth occur underwater.
Suboceanic, or submarine landslides can involve the
movement of rocks and sediments entirely beneath the sea, or
they can begin as partly above-water landslides that later
enter the ocean.
Like open-air landslides, submarine landslides often strike
steep inclines but, unlike open air slides, submarine landslides
also hit very slightly dipping terrain.
Submarine
Landslides
Best evidence suggests that the potential for suboceanic
landslides exists pretty much globally, whether in tectonically
active or tectonically inactive regions.
A primary hazard of submarine landslides, like their land
bound relatives, is the destruction of man-made structures
along their path.
Undersea slope failures present an additional threat --
landslide-generated tsunami waves.
Earthquake
A 7.2 magnitude
earthquake struck.
Epicenter of 44.5°N,
56.3°W
Experienced as far away
as New York and
Montreal.
Seismic waves recorded
up in Denmark.
http://www.geophys.washingtion.edu/tsunamis/general/historic/grandbanks29. html
Grand Banks 1929 / Worst Case Scenario
First documented submarine landslide
The first recorded sub
oceanic landslide was
recorded in 1929 near
Newfoundland.
The landslide created a
tsunami and killed nearly
30 people in Nova Scotia
and Newfoundland.
100 m/s and retaining 20m
height
Grand Banks, Newfoundland, 1929
1929 Grand
Banks, Newfoundland, C
anada - 7.2 magnitude.
Earthquake tsunami run-
up extended 480 m inland to
an elevation of more than
8.5 m above sea level.
Broke Trans-Atlantic Cables
TransAtlantic cable
Damages
http://www.usgs.gov/faq/list_faq_by_category/get_answer.asp?id=970
The tsunamis killed 28 people
Left 10,000 more homeless
The submarine landslide destroyed 12
transatlantic telegraph cables.
Geologic Findings
The first recognition of
submarine landslides ability to
cause a tsunami.
The first recognition of
turbidity currents in a natural
environment.
This event created a
Turbidity Current – a
current of rapidly moving,
sediment-laden water moving
down a slope through air,
water, or another fluid.
http:en.wikipedia.org/wiki/Turbidity_current
Geological Evidence
Photographs of 1929 tsunami deposits at Taylor's Bay on
Newfoundland's southern coast. Photograph shows three
sandy units deposited by consecutive waves.
http://earthquakescanada.nrcan.gc.ca/histor/20th-eme/1929/1929-eng.php
1918 - Puerto
Rican Submarine
Landslide
A 7.5 magnitude earthquake off of the Puerto Rican Trench.
The deepest point in the W. Atlantic, produced waves and run-
up on the order of 4-6 m. It killed 40 people.
Caused surges in water levels at tide gauges: Atlantic City, NJ.
Pending
Disaster
San Pedro
Landslide &
tsunami
Submarine slope failures and active faults, all of which can
generate tsunamis, are known on the shelf and slope of San
Pedro.
Large slope failures are present on the San Pedro Escarpment
and on the basin slope. The escarpment has a long history of
slope failures.
San Pedro Landslide
& tsunami
The San Pedro Bay is home to the largest container ports in the
United States.
A large earthquake or tsunami would seriously impact California’s
economy and the nations.
The major earthquake could cause seafloor uplift of eight
feet or more.
San Pedro Landslide & tsunami
These areas of
restraining bends
created uplift on
the sea floor.
During an earthquake,
these bends
can push the seafloor up
and generate a tsunami.
Submarine landslide
complex in the Santa
Barbara Channel in the
vicinity of Goleta, California
The Goleta Submarine Landslide Complex is located in the
Santa Barbara Channel near Coal Oil Point near Goleta and
Santa Barbara.
The image was generated from a multibeam-bathametric
data.
It shows large tongues of sediment created by undersea
landslides that extend in some places more than 6 miles (10
kilometers) onto the seafloor in the Santa Barbara Channel
from their source of failure along the margin near the break in
slope of the continental shelf edge.
Past Submarine
landslide in the Santa
Barbara Channel
Research shows that record submarine landslide failures in the
Santa Barbara area began about 200,000 years ago, with two
of the large landslide slope having formed about 10,000 and
8,000 years ago.
Scientists are concerned that such offshore landslides could
cause tsunamis that affect the Santa Barbara coast with little
advanced warning.
Past Submarine
landslide in the
Santa Barbara
Channel
Scientist Gary Greene, head of the research notes: "This slide
evidently moved in three different events. Each event
displaced enough sediment to be capable of generating a
tsunami, if the displacements occurred rapidly.“
Resulting maps revealed submarine landslides along the
northern flank of the basin. Greene was able to map in detail
a large, 130 km slump off Coal Oil Point near Goleta. This
prominent slump is 14.6 km long by 10.5 km wide and
extends from 90 meters to a depth of 570 meters.
Algunas Submarine Landslide, So. Africa
The largest documented slope failure.
Distance landslide traveled is 140 km
The Agulhas submarine Landslide occurred after the Pliocene
Epoch which ended nearly 1.8 million years ago.
Volcanic Eruption
Krakatoa, Indonesia 1883 Sunset in England, 1883
It caused a drop in global temperatures for 5 years.
The airborne particles led to spectacular sunsets for years.
The eruption produced a black cloud of volcanic debris that
blocked out all sunlight in the region for 3 days.
It reduced incoming solar radiation worldwide by 10%.
Krakatoa, Indonesia 1883
Krakatau eruption (1883) in The explosion destroyed the
Indonesia - killed more than entire island.
36,000 people It created a huge tsunami
that killed thousands of
people that were trying to
seek shelter from the ash,
rock and debris that was
raining down on them.
In it’s place , “The son of
Krakatoa” is now growing up
from the ocean floor. Every
bit as dangerous as it’s
father, today it violently spits
out gas, ash and pyroclastic
rock.
Sumatran
Undersea
Mega Thrust
Earthquake
December 26, 2004 at 7:58AM
Magnitude 9.1 – 9.3
Epicenter was off the west coast of Sumatra, Indonesia
Undersea mega thrust earthquake
Occurred at subduction zone at convergent plate boundry
Estimated 994 mile long fault line ruptured
about 50 feet
On the morning of 12/26/04 at
7:58:49 am, M 9.0 earthquake
~100 km (60 mi) off W. Coast
Northern Sumatra, Indonesia.
A huge landslide of the
West coast caused by a
underwater earthquake is
how the Tsunami began.
Sumatran Undersea
Mega Thrust Earthquake
Set off massive waves
1200 km section of (“tsunami”) that raced
earth’s crust shifted towards the west and east.
~10-20 mi beneath the Over a period of 10
Indian Ocean. hours, tsunami struck
Quake released stored coasts of over 12 countries.
elastic energy equal to Major damage and deaths
~23,000 Hiroshima around the Indian
atomic bombs. Ocean, from Southeast Asia
Uplifted the sea floor to Africa.
several meters, One of the most
displacing billions of devastating disasters in
modern human history.
gallons of seawater.
The Earthquake
Second largest
earthquake ever
recorded Energy released
similar
to 9,560 gigatons of TNT
Aftershocks felt for up to 3 to
4 months after the quake
Largest aftershock
Registered a magnitude of
8.7
Produced its own
aftershock
The Earthquake
Felt as far away as
Bangladesh, Malaysia, Myanmar, Thailand, Singapore, M
aldives
Earthquake lasted 8.3 to 10 minutes long
Longest earthquake ever observed
Entire planet vibrated ~1cm
The Tsunami
Earthquake triggered a series of tsunami waves
Hardest hit were Indonesia, Sri Lanka, India and Thailand
Waves
Reached nearly 100 feet in height
Traveled ~1.24 miles inland
Sea receded as far as 1.6 miles
Took 15 minutes to 7 hours to reach various coastlines
The Tsunami
The tsunami wave reached as far as South Africa
Approx. 5,300 miles away
16 hours later
Resulted in the death of ~225,000 people across 11 countries
1/3 were children
4x more women died than men
US Military Helicopter takes this shot of a town near the
coast of Sumatra that lies in ruin, on January 2, 2005.
DEATH TOLLS FROM
TSUINAMI 2004
As of February 22, 2005 the Thailand – 5,395 dead w/
death toll stood at 169,752 2,993 missing.
people dead with, 127,294 Somalia – 82 dead w/ 26
people listed as missing. missing.
The death tool stood as Malaysia – 68 dead.
follows: Myanmar – 59 dead.
Indonesia – 122,232 dead Tanzania – 10 dead
with 113,937 missing. according to the UN.
Sri Lanka – 30,974 dead Seychelles – 3 dead
still missing 4,697 w/ according to the UN.
100,000 families displaced.
Bangladesh - 2 dead
India – 10,766 dead with according to the UN.
5,640 missing.
Kenya – 1 dead according
to Kenya Media.
Photo taken by Henrvk Kotowski on
December 26, 2004, showing the
aftermath.
There was ample time to issue
warning, HOWEVER, no
warning system existed for this
part of the world!
Effects of Earthquakes
Before &
After
Impact Dampening
Coral reefs
Destroyed by inhabitants to make way for fisherman and
shrimp farmers
Tsunamis would have rushed against the reef, lessening
power
Mangrove Trees
Removed along the coastline for residences
Could have blocked much of the incoming force
The significance of coral reefs and
mangrove swamps and dunes
Many countries across Asia have played a significant role in the
destruction caused by the Tsunami, by destroying the coral
surroundings of their beaches to make way for economics-
shrimp farming.
On Surin Island Chain of Thailand's coast many people were
saved as the tsunami rushed against the coral reefs protecting
the islands.
The removal of coastal mangrove trees has also intensified the
effect of tsunami waves in some locations.
Another factor relating to an increase in damage is the removal
of coastal sand dunes.
EARTHQUAKE
The only recorded earthquakes with larger Mw than the
Sumatran earthquake, were the 1960 Chilean and the 1964
Alaskan earthquakes.
The shock waves of the earthquake was felt across the planet,
as far away as Oklahoma where vertical movements of 3mm
was recorded.
The sudden vertical rise of the seabed by several meters during
the earthquake, displaced massive volumes of water, resulting
in a Tsunami that struck the coasts of the Indian Ocean.
A Wake-up Call
We as people contribute to our own environments
natural breakdown of resilience.
Nothing could have prevented this phenomena, but the
manner in which we choose to use our resources could
have lessen the impact of this natural disaster.
References
http://www.wikipedia.com
http://www.ess.washington.edu/tsunami/sumatra.htm
http://www.csupomona.edu/~marshall/ind_oc_tsunami_lec.v4.htm
www.geo.arizona.edu
images.google.com
http://www.mbari.org/news/news_releases/2000/dec15_greene.html
www.es.ucsc.edu/~ward/papers/ward&day.pdf
www.tsunamis.com
Real pictures of tsunami
www.wsspc.org.com
Western States Seismic Policy Council
en.wikipedia.org
Tsunami
News.nationalgeographic.com/news/2004/12/1227_041226_tsunami.htm
Tsunami Sumatra 2004
References
http://walrus.wr.usgs.gov/tsunami/itst.html
http://www.drgeorgepc.com/tsunami1998PNG.html
http://walrus.wr.usgs.gov/tsunami/png.html
http://www.sfgate.com
•1929 Grand Banks Earthquake:
http:en.wikipedia.org/wiki/1929_Grand_Banks_earthquake;
•The 1929 Grand Banks Landslide and Tsunami Revisited: http://adsabs.harvard.edu
/abs/2006AGUFMOS33E..05M;.
•The 1929 Grand Banks Tsunami: http://www.geophys.washingtion.edu/tsunamis
/general/historic/grandbanks29. html;.
Grand Banks: http://www.aquatic.uoguelph.ca/oceans/atlanticoceanweb
/AOFloor/Grandbanks.htm;.
•Grand Banks: http://earthquakescanada.nrcan.gc.ca/histor/20th-eme/1929/1929-
•How Do Landslides Create Tsunamis?: http://www.usgs.gov/faq/list_faq_by_category
/get_answer.asp?id=970;.
•Turbidity Current: http:en.wikipedia.org/wiki/Turbidity_current;.
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