Tsunamis
How bad are they?
By
Travis Jordan
Reid Best
"Suddenly I heard a shout, ‘Big wave!’ The streetlights around us exploded
almost in the same instant. I looked up and saw a locally well known fishing
boat coming up over the Wailoa Bridge"
-- Susan Maeda Veriato on the 1960 tsunami in Hilo, as told to her son Travis
PTM Archive Photo: Yasuki Arakaki collection; Photographer: Cecilio Licos
What is a tsunami?
Beginning
The word is Japanese and means "harbor wave,”because of the
effect on the low coastal areas. A Tsunami is a giant, or series of big
waves caused by an immediate vertical disturbance that displaces
the water from its normal position. This causes the water mass to
try to regain normality by pushing away the displaced water. "The
main factor which determines the initial size of a tsunami is the
amount of vertical sea floor deformation" (WACTC). 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.
Middle
When a tsunami crosses the ocean its length (from crest to crest) can
be 100 miles or more, and its trough won’t be any higher than two
feet. A tsunami travels at speeds of 600 miles per hour in the deepest
ocean. But once it reaches the shoaling water of the coastline its speed
decreases, and the wave becomes increasingly higher. It is in the
shallow waters that waves can be 100 feet high. Tsunamis
are
not created from the wind. Wind-created waves have a
period of five to twenty seconds, and about 100 to 200 meters
wavelengths. While tsunamis have periods that range from ten
minutes to two hours and 300 mile long wavelengths.
End
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.
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.
Art work
Great Wave off the
Coast of Kanagawa,
by Hokusai, a
Japanese artist. This
piece of art work is
misleading Because
tsunami are not
always huge breaking
waves as depicted in
the print.
Most Destructive recent Tsunamis
1929 Grand Banks
1957 Aleutian
1975 Hawaii
1946 Aleutian
1960 Chile
1996 Peru
1952 Kamchatka
1964 Prince William Sound
Skip
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.
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.
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.
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.
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.
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.
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.
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.
Which is worst? Regional or
local tsunamis?
Regional tsunami are very destructive but local
tsunamis also cause significant damage. Local
tsunamis are created by landslides, which are started
by earthquakes. At the Valdez Inlet a giant landslide
started by the earthquake created a tsunami that had a
run-up of 67.0 m at the inlet. In areas where local
tsunamis are created by landslides, nearby cities are
not given any warning of the oncoming waves.
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).
The American Red Cross
The American red crosses guild to
help you prepare, get through, and
survive a tsunami.
How to prepare for a tsunami?
Avoid building or living in buildings within several hundred feet of the
coastline. These areas are more likely to experience damage from tsunamis,
strong winds, or coastal storms.
Make a list of items to bring inside in the event of a tsunami. A list will help
you remember anything that can be swept away by tsunami waters.
Elevate coastal homes. Most tsunami waves are less than 10 feet. Elevating
your house will help reduce damage to your property from most tsunamis.
Follow flood preparedness precautions. Tsunamis are large amounts of water
that crash onto the coastline, creating floods.
Have an engineer check your home and advise about ways to make it more
resistant to tsunami water. There may be ways to divert waves away from your
property. Improperly built walls could make your situation worse. Consult with a
professional for advice.
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.
What to do after a tsunami?
Skip
Continue listening to a NOAA Weather Radio, Coast Guard emergency frequency station, or other
reliable source for emergency information. The tsunami may have damaged roads, bridges, or other
places that may be unsafe.
Help injured or trapped persons. Give first aid where appropriate. Call for help. Do not move
seriously injured persons unless they are in immediate danger of further injury.
Help a neighbor who may require special assistance--infants, elderly people, and people with
disabilities. Elderly people and people with disabilities may require additional assistance. People who
care for them or who have large families may need additional assistance in emergency situations.
Use the telephone only for emergency calls. Telephone lines are frequently overwhelmed in disaster
situations. They need to be clear for emergency calls to get through.
Stay out of the building if waters remain around it. Tsunami waters, like flood waters, can undermine
foundations, causing buildings to sink, floors to crack, or walls to collapse.
When re-entering buildings or homes, use extreme caution. Tsunami-driven flood waters may have
damaged buildings where you least expect it. Carefully watch every step you take.
Wear sturdy shoes. The most common injury following a disaster is cut feet.
Use battery-powered lanterns or flashlights when examining buildings. Battery-powered lighting is
the safest and easiest, preventing fire hazard for the user, occupants, and building.
Examine walls, floors, doors, staircases, and windows to make sure that the building is not in
danger of collapsing.
Inspect foundations for cracks or other damage. Cracks and damage to a foundation can render a
building uninhabitable.
next
Look for fire hazards. There may be broken or leaking gas lines, flooded electrical circuits, or submerged furnaces or
electrical appliances. Flammable or explosive materials may come from upstream. Fire is the most frequent hazard
following floods.
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 using 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 burning 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. Electrical equipment should be checked and dried before being returned to
service.
Check for sewage and water line damage. If you suspect sewage lines are damaged, avoid using the toilets and call a
plumber. If water pipes are damaged, contact the water company and avoid using water from the tap. You can obtain safe
water from undamaged water heaters or by melting ice cubes.
Use tap water if local health officials advise it is safe.
Watch out for animals, especially poisonous snakes, that may have come into buildings with the water. Use a
stick to poke through debris. Tsunami flood waters flush snakes and animals out of their homes.
Watch for loose plaster, drywall, and ceilings that could fall.
Take pictures of the damage, both of the building and its contents, for insurance claims.
Open the 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. Any food that has come in contact with flood waters may be contaminated and should be thrown
out.
Help
There is no real place for the people
to go after a tsunami hit. This is
because mostly everything along the
coast is destroyed, costing millions
of dollars of damage. The people
can go farther in shore for help
because the tsunami doesn’t go far
in shore.There is no real aid from
the government to help them, but
there is the red cross that helps
anyone after a disaster hits. The
disaster usually destroys everything
in it’s path. But the red cross is
always there to help.
Effects on people
On July 12. 1993, a powerful earthquake west of Hokkaido
in the Sea of Japan unleashed a tsunami that devastated
nearby Okushiri Island. The video you will see here shows
Aonae Cape, a small peninsula that points south off of
Okushiri. The peninsula was completely overtopped by the
giant wave, to heights of over 10 m. (the largest recorded
wave run-up on the island was nearly 30 m!) In the image
above, the wave approached from the left and swept over
the land. Structures remaining after the wave attack were
destroyed by the fires that engulfed the area due to broken
gas lines and toppled fuel containers.
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.
Thank you for watching
our presentation!
To Info
Info
•
http://www.tsunami.org/
• Suddenly I heard a shout, “Big Wave!”
– To slide 2
• http://www.geophys.washington.edu/tsunami/general/physics/physics.html
• http://www.geo.arizona.edu/~/ablauser/hazard/4hilo.ht
ml
• What is a tsunami?
– To slide 3
• Beginning
– To slide 4
• Middle
– To slide 5
• End
– To slide 6
Info 2
http://www.geophys.washington.edu/tsunami/
Art work
To slide 7
A survey of great tsunamis
Map (picture)
History
Pictures
To slide 8
To slide 9
To slide 10
To slide 11
To slide 12
To slide 13
To slide 14
To slide 15
Which is worst? Regional or local tsunamis?
To slide 17
http://www.geophys.washington.edu/tsunami/Peru/overview.html
Peru
To slide 16
Info 3
http://www.pmel.noaa.gov/tsunami/Faq/x005_highest
What is the highest known tsunami?
http://images.usatoday.com/news/healthscience/science/wonderquest/images/2002-04-24tsunami.jpg
Picture of the highest known tsunami
To slide 18
http://www.redcross.org/services/disaster/keepsafe/tsunami.html
The American red cross
To slide 19
How to prepare for a tsunami?
To slide 20
What to do during a tsunami?
To slide 21
What to do after a tsunami?
To slide 22
To slide 23
To slide 24
Help
www.threerivers.org/ photos/V02/
Help picture
To slide 25
Info 4
http://www.pmel.noaa.gov/tsunami/Faq/x005_highest
What is the highest known tsunami?
http://images.usatoday.com/news/healthscience/science/wonderquest/images/2002-04-24tsunami.jpg
Picture of the highest known tsunami
To slide 18
http://www.redcross.org/services/disaster/keepsafe/tsunami.html
The American red cross
To slide 19
How to prepare for a tsunami?
To slide 20
What to do during a tsunami?
To slide 21
What to do after a tsunami?
To slide 22
To slide 23
To slide 24
Help
www.threerivers.org/ photos/V02/
Help picture
To slide 25
Info 5
http://www.usc.edu/dept/tsunamis/video/okuvid/index.html
Effects on people (video)
To slide 26
http://www.usc.edu/dept/tsunamis/video/fieldvid/index.html
Effects on nature (video)
To slide 27