Past Tsunamis
Courtney Daniels danielsc@uwec.edu 
                
 
Part of Waves of Devastation, a class website on the Indian Ocean Tsunami & Global Environmental Injustice, produced by students of Geography 378 (International Environmental Problems & Policy) at the University of Wisconsin-Eau Claire, USA, Spring 2005.
 

 

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.
 
 

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

 

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.

 

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