1. Tsunami
By
Harish Kumar Lekkala
117R1A0132

2. What is a tsunami….

3. Tsunami
•The term tsunami comes from the Japanese ; i.e (tsu) meaning
"harbour " and ; ( nami ) meaning “wave” means “harbour wave”.
Tsunamis are not created from the wind! Earthquakes, landslides,
volcanic eruptions, explosions, and even an impact from space,
such as meteorites, can generate tsunamis. Tsunamis can destroy
coastlines, causing property damage and loss of life. A lot of the
loss of life is caused by drowning.
•As the tsunami leaves the deeper water of the open ocean
and travels into the more shallow waters near the coast, As
the tsunami heads toward the shallow water the speed of the
tsunami will decrease but the energy of the tsunami will stay
the same and the wave grows bigger this happens because its
called a "shoaling" effect.

4. As the tsunami reaches the shore, a rapidly falling or rising tide may
appear. Undersea features and the slope of the beach helps change the
tsunami as it approaches the shore. Not very often are tsunamis large
breaking waves. Sometimes they break far offshore. If the tsunami moves
into a bay or river a bore (a step-like wave with a steep breaking front) can
occur. The water level will rise from 50-100 feet. This flood can travel
1000 feet or more inland. When the water retreats back out to the ocean all
the damaged objects will get drag back into the ocean . Run-up height is the
maximum vertical height onshore above sea level. Since tsunamis are
caused by earthquakes, A tsunami is caused by a earthquake therefore we
can
not predict when there gonna happen and the intensity of the tsunami. You
can never tell exactly when it’s finished because there are after shocks
more earthquakes and local tsunamis from landslides.

5. Schematic plate tectonic
setting for tsunami generation
NOAA
TRENCH
Commonly, in mega-thrust earthquakes, a very
large area of the ocean floor is uplifted

6. Tsunami wave propagation characteristics –
note that as water depth becomes smaller,
waves slow down, become shorter wavelength,
and have larger amplitude.
NOAA

7. Water waves animation
Direction of propagation

8. Tsunami Sources
• Earthquakes (e.g. Sumatra, 2004: >200,000 people
killed; Papa New Guinea, 1998: ~3,000 people
killed)
• Volcanic eruptions (e.g. Krakatoa, 1883: tsunamis
killed 30,000 people; Santorini, 2002).
• Mass Movement (e.g. Alaska, 1958: waves up to
518 m high formed in Lituya Bay).
• Extraterrestrial Impacts - large impacts have the
potential to create enormous tsunamis.

9. Tsunami Locations
• Large subduction zones produce the most
tsunamis. The Pacific, rimmed with
subduction zones, has the most tsunamis.
– Pacific ~ 80%
– Atlantic ~ 10%
– Remaning area ~ 10%

10. Tsunami Travel Times (Hawaii)
From Merritts et al., 1998

11. Most Destructive recent Tsunamis
1929 Grand Banks 1975 Hawaii
1960 Chile 1996 Peru
1964 Prince William Sound
1946 Aleutian
1957 Aleutian
1952 Kamchatka 2004 Indian Ocean
tsunami

12. Tsunami Statistics
Tsunami Statistics (NOAA)
(Dec. 26, 2004 tsunami resulted in over 200,000 deaths)

13. Propagation, Response and Warning Times
for the M9.0 Sumatra EQ
16 minutes after OT
P S
Northern Sumatra
Tsunami inundation spreads
further along the Sumatran
coast and reaches the
Nicobar Islands
NEIC
First automatic location released
at NEIC
Pager notification to about 10
people in the USGS
PTWC
Confers with NEIC on the
location and magnitude of the
Earthquake
Release Tsunami Information Bulletin

14. 1929 Grand Banks Tsunami
November 18, 1929, at approximately 5:00pm, Newfoundland experienced an Earthquake off the
coast of Grand Banks, Newfoundland. That's when a tsunami was started by an under water landslide and the
earthquake, which was a Richter magnitude of 7.2 with an epicenter of 44.5°N, 56.3°W. After the tsunami hit
it caused $400,000 in damage and killed 29 people, the biggest death rate to occur an in Canada from an
earthquake.
This tsunami`s most damage was caused by the underwater landslide. The landslide added to the
size of the tsunami and damaged many kilometers of 12 different transatlantic cables. The most of the
economy`s money was spent on the repair costs the for transatlantic cables. Unaware of the danger coming
from the sea, the communities of Burin Peninsula, Newfoundland, there was a huge amount of damage and
loss of 29 lives. The tsunami was spotted as far as South Carolina and Portugal.
In 1952 American scientists from Columbia University put together the pieces of the broken cables
that led to the landslide and the first documentation of a turbidity current. Scientists are looking at layers of
sand believed to be deposited by other tsunamis in an effort to determine the occurrence rates of large
earthquakes. One sand layer, were thought to be deposited by the tsunami in 1929, in Taylor's Bay they found
13 cm below the turf line. The occurrences of large tsunamis, such as the one in 1929, are dependent upon
deposition of sediments offshore because it was the landslide, which made the tsunami so powerful. The
deposition of such a large volume of sediments will take awhile before there is enough to for an underwater
landslide of size as in 1929.

15. 1946 Aleutian
April 1, 1946, at 12:29 GMT, an earthquake shook the Aleutian Islands of Alaska. There was a Pacific-wide tsunami
that had been started by the earthquake, The tsunami had a surface-wave magnitude of 7.8, an epicenter of 52.8° N,
163.5° W, and a focal depth of 25 km. The tsunami took the lives of more than 165 people.
There was one structure affected by the tsunami it was a new built Scotch Cap lighthouse on Unimak Island, Alaska.
In the Hawaiian Islands was one of the hardest hit locations, by the tsunami. Pololu Valley it recorded the highest
run-up of 12.0 m. Hilo was the city that received the most costly damage on the Island of Hawaii. The tsunami
arrived at Hilo 4.9 hours after it originated in the Aleutian Islands and the run-up was measured at 8.1 m. Hilo
received approximately $26 million in damage and 96 people lost their lives.
The large number of deaths from this event brought the people to realize that a warning system was necessary to
make sure the safety of the population. August 12, 1948, a plan was approved and the Seismic Sea Wave Warning
System was established. They changed the Pacific Tsunami Warning System.

16. 1952 Kamchatka
On November 4, 1952, at approximately 5:00pm, an earthquake occurred off the coast of the
Kamchatka Peninsula, Russia. The tsunami was started by the earthquake that traveled pacific wide, it
had a focal depth of 30 km, a magnitude of 8.2, and an epicenter of 52.8° N, 159.5° E. In Hawaii six
cows died but no human lives were lost. Damage was estimated in the range of $800,000- $1,000,000
(in 1952).
The Hawaiian Islands had far worse damage. The waves destroyed piers and boats, knocked over
telephone poles alone with their lines, washed away beaches, and flooded homeowners lawns. A
cement barge was thrown into a freighter in Honolulu Harbor. In Hilo Bay the bridge that connects
Coconut Island to the shore, was lifted off its foundation and then smashed down into the water. This
was caused by one of the waves.
At Coconut Island the run-up was 12 feet. At Hilo the run-up was 11 1/2 feet a new record. At Reed's
Bay, the water level was as high as 11 feet. Most all the other coastal cities of Hawaii, the water rise
wasn’t noticeable. The destruction vary from place to place. Without knowing the size of damage,
Hawaii had to warn homeowners to keep them away from the shoreline until was safe to go home.
Midway Island’s roads were flooded, because of the Kamchatka
tsunami 3,000 km away from the origin.
Photograph Credit: U.S. Navy. Source: National Geophysical
Data Center.

17. 1957 Aleutian
March 9, 1957, at 2:22 GMT, an earthquake hit south of Andrean of Islands, in the Aleutian Islands of
Alaska. It was Pacific-wide tsunami that was started by the earthquake, which had a surface-wave magnitude
of 8.3, an epicenter of 51.5° N, 175.7° W, and a focal depth of 33 km. In this event there were no lives lost,
the Hawaiian Islands had received approximately 5 million dollars.
The Island of Kauai, Hawaii, was hit by this tsunami twice as bad than by the Aleutian Islands tsunami in
1946. Houses were washed out and destroyed at Wainiha and Kalihiwai. At Haena, The heights of the waves
reached about 16 m. At Hilo, Hawaii, the run-up was reached 3.9 m. In Hilo Bay, Coconut Island was covered
by 1 m of water and the bridge connecting it to shore was destroyed.
There was major a wave at Laie Point on the Island of Oahu, Hawaii. The northwest side of the Hawaiian
Islands received high levels of water. Both the 1946 and 1957 tsunamis occurred at pretty much the same
place (the Aleutian Islands). The 1957 earthquake released more energy than the earthquake of 1946. The
tsunamis force by this 1957 event caused less damage than the tsunami of 1946. This potential of destructive
power of a tsunami forces Pacific Tsunami.
These pictures are in a series of three sequential photos show the arrival of a major wave at Laie Point
on the Island of Oahu, Hawaii. Photograph Credit: Henry Helbush. Source: National Geophysical
Data Center.

18. 1996 Peru
February 21, 1996, at 12:51 p.m. GMT (7:51 a.m. local time), there was a large
Earthquake that struck approximately 130 Km off the northern coastal region of Peru
(9.6S, 80.2W). The earthquake had a Harvard Mw estimate of 7.5 and USGS Mw
estimate of 7.3. The earthquake generated a tsunami that reached the center of Peru on
the city of Chimbote. The Effects of the tsunami were observed from Pascasmayo, in the
department of La Liberated, to the Port of Callao near Lima. The straight line distance
between these two locations is approximately 590 Km. The tsunami was recorded by
mid-Pacific tide gages, 60 cm at Easter Island, and 25 cm at Hilo, Hawaii. The
aftershock pattern ranged from 120 to 180 Km offshore near the Peru-Chile trench and
appeared to parallel the Peruvian coastline.
The International Survey
Team who gathered the data.

19. 1960 Chilean Tsunami
On May 22, 1960, at 7:11 , an earthquake occurred off the coast of South Central Chile. There
was a tsunami triggered by the earthquake, which had a surface-wave magnitude of 8.6, an
epicenter of 39.5° S, 74.5° W, and a focal
depth of 33 km. The number of deaths caused by both the tsunami and the earthquake and
approximately 490 to 2,290. The Damage cost was estimates well over a half billion dollars.
The inhabitants, feared the earthquake, they were in boats to escape the shaking. The trough of
the tsunami arrived just 10 to 15 minutes after the earthquake, along more than 500 m of the
coast. After the tsunami had gone
by the Hawaiian Islands had damage costs that were approximately at $24 million and 61
people had lost here lives. Hilo, on the main island of Hawaii, was the hardest hit city in the
islands. The tsunami arrived at Hilo 14.8 hrs after it was created off the coast of South Central
Chile. The waves at Hilo was measured at 10.7 m.
An aerial view of the coast of Isla
Chiloe, Chile, showing the tsunami
damage.

20. 1964 Prince William Sound
On March 28, 1964, at 03:28 GMT, an earthquake occurred in Prince William Sound of Alaska
triggering a Pacific-wide tsunami. The earthquake had a surface-wave magnitude of 8.4, an epicenter
of 61.1° N, 147.5° W, and a depth of 23 km. The tsunami was responsible for taking more then 122
people and causing over $106 million in damage.
Whittier incurred $10 million in property damage. One of the waves, probably the same one that
caused the major damage in Whittier, reached a height of 31.7 m above low tide They also caused
great damage to the small boat harbor. The tsunami took the lives of thirteen people at Whittier, then a
community of 70 people The greatest damages suffered by any location was Alaska. In Alaska 106
people lost their lives and $84 million in damage.
The Tsunami left a 2 x 12 inch plank of wood through a
truck tire at Whittier, Alaska. Whittier incurred $10
million dollars in property damage.

21. 1975 Hawaii
November 29, 1975, at 2:48 GMT, a tsunami was created by an earth quake off
the shore of Hawaii. The tsunami had a magnitude of 7.2, an epicenter of 19.3°
N, 155.0° W, and a focal depth of 8 km. At Halape, there was 32 campers. Out of
the 32, 19 were injured and 2 died. It sounded like boulders falling, there was a
second earthquake that woke the campers. They all ran to the coconut grove
which was closer to the ocean. The campers were awaken by a second quake that
sent large boulders down the cliff and the rest of the campers to fleed toward the
sea. These campers had to go back to cliffs when the other campers at the
coconut grove fleeing the rising ocean with there cries of a tsunami. The tsunamis
first wave that alarmed the campers was only 1.5 m. The second wave, however,
was 7.9 m carried campers into a ditch near the base of cliff where they remained
until the end. There were two campers that died from this.
The largest recorded run-up was 14.3 m at Keauhou Landing, Hawaii Island.
Also on the Island of Hawaii in the small bay of Punaluu the run-up reached 7.6
m.At Punaluu houses were swept off their foundations and properties were
damaged.

22. What is the highest known
tsunami?
The highest tsunami, with a reliably measurement
on record occurred on July 9, 1958 in Lituya Bay,
Alaska. This was caused by a landslide that fell
into the bay. This unusual happening, caused by a
wave to surge up the slope on the opposite side of
the bay to a height of 518 m(1,700 ft). Scientists
believe that bigger tsunamis happened a long time
ago by asteroids, or large meteors, falling into the
ocean. Two places their looking for evidence of
these tsunamis are Hawaii and the coast on the
Gulf of Mexico. The landslide came from the
mountain(A) into the bay(B).

23. 2004 Indian Ocean earthquake
and tsunami

24. • The 2004 Indian Ocean earthquake was
an undersea megathrust earthquake that occurred at
00:58:53 UTC on Sunday, 26 December 2004, with
an epicentre off the west coast of Sumatra, Indonesia. The
quake itself is known by the scientific community as
the Sumatra–Andaman earthquake. The
resulting tsunami was given various names, including
the 2004 Indian Ocean tsunami, South Asian
tsunami, Indonesian tsunami, the Christmas tsunami and
the Boxing Day tsunami.

25. The earthquake was caused when the Indian Plate was subducted by the
Burma Plate and triggered a series of devastating tsunamis along the coasts of
most landmasses bordering the Indian Ocean, killing over 230,000 people in
fourteen countries, and inundating coastal communities with waves up to 30
meters (100 ft) high. It was one of the deadliest natural disasters in recorded
history. Indonesia was the hardest-hit country, followed by Sri Lanka, India,
and Thailand.
With a magnitude of Mw 9.1–9.3, it is the third largest earthquake ever
recorded on a seismograph. The earthquake had the longest duration of
faulting ever observed, between 8.3 and 10 minutes. It caused the entire planet
to vibrate as much as 1 centimetre (0.4 inches)and triggered other earthquakes
as far away as Alaska. Its epicentre was between Simeulueand mainland
Indonesia.The plight of the affected people and countriesprompted a
worldwide humanitarian response. In all, the worldwide community donated
more than $14 billion (2004 US$) in humanitarian aid.

26. 16 minutes after OT 104 minutes after OT

27. 26 Dec. 2004 Tsunami max. wave height and
arrival time
Geist, Titov and Synolakis, Tsunami: Wave of Change,
Scientific American, January, 2006.

28. Seismic Eruption software: http://www.geol.binghamton.edu/faculty/jones/
Indonesia area historical earthquakes files, download from:
http://web.ics.purdue.edu/~braile/edumod/tsunami/TsunamiFiles.htm

29. Seismic Eruption software: http://www.geol.binghamton.edu/faculty/jones/
Sumatra earthquake and aftershocks files, download from:
http://web.ics.purdue.edu/~braile/edumod/tsunami/TsunamiFiles.htm

30. Propagation, Response and Warning Times
for the M9.0 Sumatra EQ
122 minutes after OT
Indian Ocean
Little communication from
Banda Aceh
Destruction in Pkuket
Tsunami hits Sri Lanka
NEIC
Continuing dialogue between
USGS scientists in Golden,
Reston and Menlo Park
No confirmation via wire
services of tsunami in the
Indian Ocean
Wire service reports of
building collapse in Banda
Aceh
Web content is being
developed and posted

31. Banda Aceh, Sumatra, before tsunami

32. Banda Aceh, Sumatra, after tsunami

33. Tsunami Warning
• As soon as an earthquake of magnitude >6.5 is
located in the sea the alarm start.
• Using computer simulations and maps like the one
in the following slide scientists forecast the time
of arrival in different locations.
• The use of Buoy and tide gauges help to verify the
effective presence of a tsunami, the alarm is given.

34. Tsunami Hazard Mitigation
• We can warn people of potential tsunamis
from distant earthquakes. Warning of near
source tsunamis is much more difficult.
• Prevention of tsunami catastrophes requires
carefully planned use of low-lying areas.
– This is not always possible, or affordable.

35. Effects on nature
The effect of nature can be quite devastating. But only
along the coastline is where all the damage is. The waves
can knock over trees, wash away beaches and floods lower
regions.
There are three videos. The first one shows the effect on
nature. The others show the effect on people.
A montage from
Papua New Guinea.
Damage on the shore
of Izmit Bay, Turkey.
Izmit shore, as
seen from the sea.

36. Effect on Humanitarian , economic
and environmental impact
A great deal of humanitarian aid was needed because of widespread damage of
the infrastructure, shortages of food and water, and economic damage.
Epidemics were of special concern due to the high population density
and tropical climate of the affected areas. The main concern of humanitarian
and government agencies was to provide sanitation facilities and fresh drinking
water to contain the spread of diseases such
as cholera, diphtheria, dysentery, typhoid and hepatitis A and B.
There was also a great concern that the death toll could increase as disease and
hunger spread. However, because of the initial quick response, this was
minimized

37. Can We Do Better? Yes
•Improved sensor networks in hazards areas of the world (seismic,
tide gauge, ocean buoys) and coordinated distribution and
processing of data
•Better information content that can better assist emergency
responders to assess the scope of the disaster
•Coordination and integration with national, regional and local
emergency response agencies and civil authorities
•Education and training at national, regional and local levels of
government and the general population

38. Protecting Yourself (Tsunami)
• Move to higher ground.
• Wait until authorities give the go ahead to
return to low-lying regions.
• Watch for surges of water in rivers and
streams near the coast.
• If you feel a strong earthquake, don’t wait
for a formal warning.

39. What to do during a tsunami?
If you feel an earthquake that lasts 20 seconds or longer when you are on
the coast; the Red cross advises you to;
Drop, cover, and hold on. You should first protect yourself from the
earthquake.
When the shaking stops, gather your family members and evacuate
quickly. Leave everything else behind. A tsunami may be coming within
minutes. Move quickly to higher ground away from the coast.
Be careful to avoid downed power lines and stay away from buildings and
bridges from which heavy objects might fall during an aftershock.

40. Tsunami velocity and amplitude equations
(These are plane layer [flat ocean bottom] equations)
1. Wave velocity controlled by water depth:
v = (g x d)1/2 where v is velocity, d is water depth
and g is the acceleration of gravity = 9.8 m/s2; so,
velocity decreases in shallower water.
2. Wave height (amplitude) increases (conservation of
energy) in shallow water:
AS = AD x (VD/VS)1/2 where AS = amplitude in shallow
water, AD = amplitude in deep water, VS = velocity
in shallow water, and VD = velocity in deep water.

42. Wave Heights – Satellite observation versus
calculated model – open ocean, deep water
~1600 km; ~2.2 hours
of waves at 750 km/hr
Geist, Titov and Synolakis, Tsunami: Wave of Change,
Scientific American, January, 2006.