What is a mega-tsunami and can it happen today?

The following is a position paper that was issued by the Tsunami Society concerning the occurrence of Mega-Tsunamis:

The mission of the Tsunami Society includes "the dissemination of knowledge about tsunamis to scientists, officials, and the public". We have established a committee of private, university, and government scientists to accomplish part of this goal by correcting misleading or invalid information released to public about this hazard. We can supply both valid, correct and important information and advice to the public, and the names of reputable scientists active in the field of tsunami, who can provide such information.

Most recently, the Discovery Channel has replayed a program alleging potential destruction of coastal areas of the Atlantic by tsunami waves which might be generated in the near future by a volcanic collapse in the Canary Islands. Other reports have involved a smaller but similar catastrophe from Kilauea volcano on the island of Hawai`i. They like to call these occurences "mega tsunamis". We would like to halt the scaremongering from these unfounded reports. We wish to provide the media with factual information so that the public can be properly informed about actual hazards of tsunamis and their mitigation.

Here are a set of facts, agreed on by committee members, about the claims in these reports:

- While the active volcano of Cumbre Vieja on Las Palma is expected to erupt again, it will not send a large part of the island into the ocean, though small landslides may occur. The Discovery program does not bring out in the interviews that such volcanic collapses are extremely rare events, separated in geologic time by thousands or even millions of years.

- No such event - a mega tsunami - has occurred in either the Atlantic or Pacific oceans in recorded history. NONE.

- The colossal collapses of Krakatau or Santorin (the two most similar known happenings) generated catastrophic waves in the immediate area but hazardous waves did not propagate to distant shores. Carefully performed numerical and experimental model experiments on such events and of the postulated Las Palma event verify that the relatively short waves from these small, though intense, occurrences do not travel as do tsunami waves from a major earthquake.

- The U.S. volcano observatory, situated on Kilauea, near the current eruption, states that there is no likelihood of that part of the island breaking off into the ocean.

- These considerations have been published in journals and discussed at conferences sponsored by the Tsunami Society.

Some papers on this subject include:

"Evaluation of the threat of Mega Tsunami Generation From ....Volcanoes on La Palma ... and Hawaii", George Pararas-Carayannis, in Science of Tsunami Hazards, Vol 20, No.5, pages 251-277, 2002.

"Modeling the La Palma Landslide Tsunami", Charles L. Mader, in Science of Tsunami Hazards, Vol. 19, No. 3, pages 160-180, 2001.

"Volcano Growth and the Evolution of the Island of Hawaii", J.G. Moore and D.A.Clague, in the Geologic Society of America Bulletin, 104, 1992.

Committee members for this report include:

Mr. George Curtis, Hilo, HI (Committee Chairman) 808-963-6670

Dr. Tad Murty, Ottawa, Canada, 613-731-8900

Dr. Laura Kong, Honolulu, HI, 808-532-6423

Dr. George Pararas-Carayannis, Honolulu, HI, 808-943-1150

Dr. Charles L. Mader, Los Alamos, NM, 808-396-9855

and all can comment on this or other tsunami matters.

For information regarding the Tsunami Society and its publications, visit: www.sthjournal.org .

For general and educational material on tsunamis, check: www.tsunami.org .

*Questions 1-12 from IOC(UNESCO) Tsunami Press Kit, IOC/ITSU-XVIII/15, Paris, 28 September 2001.

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