Although the December
26th tsunami was a horrific environmental disaster, it was not the
only tsunami that has caused widespread destruction. Historically
tsunamis have affected coastlines and islands worldwide. Over the
past 240 years in the United States alone, 24 tsunamis have been
recorded. Since 1646, six tsunamis have killed more than 350 people
and damaged a half billion dollars of property in Hawaii, Alaska
and the West Coast. The information in this page will focus on past
tsunamis worldwide and their effect on the understanding of tsunamis.
According to the Geological
Survey of Canada the Richter scale is used to measure the magnitude
of an earthquake. The magnitude of an earthquake is a measure of
the amount of energy released. The scale is logarithmic, therefore
the intensity of the earthquake measured increases greatly from
each measure on the scale. For example:
Magnitude:
1 to 3:
Recorded on local seismographs, but generally not felt.
3 to 4: Often felt, no damage.
5:
Felt widely, slight damage near epicenter.
6:
Damage to poorly constructed buildings and other structures within
10's km
7:
"Major" earthquake, causes serious damage up to ~100 km
8:
"Great" earthquake, great destruction, loss of life over
several 100 km
9:
Rare great earthquake, major damage over a large region over 1000
km (such as Chile 1960, Alaska 1964, Indonesia 2004)
Some
Past Tsunamis
6100
B.C. – Norway
Storegga
Slides, landslides that occurred under the water near the edge of
Norway’s continental shelf. An area roughly the size of Iceland
shifted causing a megatsunami in the North Atlantic Ocean.
1650
B.C. – Santorini
A
Greek volcanic island eruption caused a tsunami, estimated to be
between 100 m and 150 m high and devastated the island of Crete
75 km away. Santorini is thought, by some, to be the cause of the
Great Flood recorded in Jewish, Christian and Islamic historical
texts.
1700–
North America and Japan
A massive tsunami caused by an earthquake along a 1,000-mile fault hit
the coastal areas of northern California, Oregon, Washington and British Columbia, on
January 26, 1700. The tsunami also caused flooding and damage in
Japan.
Geologist Brian Atwater of the U.S. Geological Survey has made many
discoveries
exposing the history of the land and the coastal peoples of the
Northwest. Layers of beach sand enabled him to pinpoint the exact
date of the 1700 tsunami. Experts say another tsunami may strike
the region in the next century.
1775
– Lisbon, Portugal
The Sunday earthquake
that devastated Lisbon sent many people fleeing from churches to
the coastlines to avoid falling debris. The tsunami that followed
killed tens of thousands of people. Overall, at least one-third
of Lisbon’s pre-earthquake population of 275,000 was killed.
1883
– Krakatoa
Krakatoa
Images
An island volcano in
Indonesia, Krakatoa exploded so dramatically in 1883 that it forced
much of the seabed below to collapse. The picture above shows the
parts of the island that fell into the sea, creating a series of
tsunamis (some reaching over 40 meters in height). This tsunami
event was experienced in multiple regions throughout the world.
Evidence of the tsunami has been found in the Indian and Pacific
Oceans, the American West Coast, South America, and even in the
English Channel. Areas in Java and Sumatra were so devastated that
they were never inhabited again, and became nature reserves.
1929
– Newfoundland
Newfoundland
Tsunami
An earthquake that measured
7.2 on the Richter scale occurred beneath the ocean on the Grand
Banks, underwater plateaus southeast of Newfoundland. The tsunami
reached heights of over 7 meters and hit the southern coast of Newfoundland,
where 28 people were killed as a result.
1946
– Aleutian Islands and Pacific Ocean
-
- On April 1, 1946 an
earthquake triggered a tsunami near the Aleutian Islands of Alaska.
The magnitude of this earthquake was 7.8. The height of the tsunami
is not known but in the Aleutian Islands it had killed 165 people
and caused over $26 million in damage. A
Pacific-wide tsunami was also created as a result of this earthquake.
The tsunami travelled through the Pacific Ocean and struck Hawaii
and the French Marquesas Islands. In the Marquesas Islands, the
local people knew the dangers of a tsunami and some of the warning
signs. Survivors of the 1946 tsunami or "taitoko" as it
is called on the islands, recall being warned by their elders to
flee for higher ground. Waters ran up into low-lying areas of this
small group of islands during this tsunami at a depth of 20 meters
in the low-lying regions. This is an important event in the history
of tsunamis as it lead to the creation of the Pacific
Warning System. This system created a method of warning areas
that could be affected by an impending tsunami before it actually
hit. The picture below shows the wave as it hit the Hawaiian city
of Hilo; note the man depicted in the photo below.
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-
-
Chilean
Tsunami
The largest recorded
earthquake of the 20th century occurred on May 22, 1960 off the
coast of south-central Chile. It was measured at a magnitude of
9.5 and generated a Pacific-wide tsunami similar to the tsunami
of 1946. The death toll in Chile was estimated at 2,300 people.
In Hilo, Hawaii the destructive waves took the lives of 61 people.
The waves also reached Japan, damaging coastlines and the fishing
industry.
1964
– Good Friday Tsunami
An
earthquake that measured 9.2 generated tsunamis that struck Alaska,
British Columbia, California, and Pacific Northwest towns. Waves
reached a height of nearly 6 meters and struck as far away as Crescent
City, California.
1979
– Tumaco, Colombia
A 7.9 magnitude earthquake
occurred off the Pacific coast of Colombia and Ecuador on December
12, 1979. This tsunami killed an estimated 400 people and left 798
wounded.
1999– Izmit Bay, Turkey
It is a
common misconception that tsunamis only occur in oceanic areas.
The 1999 tsunami that struck parts of western Turkey originated
in the Sea of Marmara, part of the Turkish Straits. The earthquake
event known as Kocaeli was located on the Northern Anatolian Fault,
sending water from the sea towards Turkey. Areas sustaining the
largest damage were Golcuk, where water run up reached a height
of 4 meters. The cities of Degirmendere and Karamursel also experienced
heavy damage due to flooding.
Factors
that could have prevented the widespread damage are still being
researched. Many things have been learned as a result of this tsunami
and the further implementation of warning systems as well as changing
the construction of buildings and roads will help to prevent future
damages.
2004
– Indian Ocean
Tsunami
Warning System
Triggered by a magnitude
9.0 earthquake, this historic tsunami sent waves throughout the
Indian Ocean, and even into the Pacific Ocean. More information
on this event can be found throughout the website. Unlike the Pacific
Ocean warning system, this region had no formal means of warning
the public of an incoming tsunami. Final death tolls are up to 300,000
deaths, with 5 million more
people affected by the tsunami
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-
Conclusion
As a result of these
historical events people have learned many things. Unfortunately,
a warning system was not implemented in time to save the lives
of the many victims of the Indian Ocean tsunami. It is the hope
of future generations that the information gathered from these
past tsunamis will help prevent more devastation in the years
to come.
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Sources
For
more information on this topic:
International
Coordination Group for the Tsunami Warning System in the Pacific:
http://ioc.unesco.org/itsu/
Krakatau,
Sundra Strait
Canadian
Geological Survey:
http://www.pgc.nrcan.gc.ca/seismo/eqinfo/richter.htm
Wikipedia
Free Encyclopedia:
http://en.wikipedia.org/wiki/Tsunami
USGS -
Surviving a Tsunami:
http://pubs.usgs.gov/circ/c1187/
USGS -
Earthquake Hazards Program:
http://quake.wr.usgs.gov/research/geology/turkey/index.html
A Survey
of Great Tsunamis:
http://www.geophys.washington.edu/tsunami/general/historic/images_46.html
The
Oregon Department of Geology and Mineral Industries:
http://www.oregongeology.com/earthquakes/Coastal/HistoricTsunamis.htm
Historical
Tsunami Database for the Pacific:
http://tsun.sscc.ru/htdbpac/
International
Tsunami Information Center:
http://www.prh.noaa.gov/itic/tsunami_events/historical/historical.html
University
of Southern California - Tsunami Research Center:
http://www.usc.edu/dept/tsunamis/2005/index.html
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