Talmud records tidal waves; researchers to report at Weizmann Institute.
By JUDY SIEGEL-ITZKOVICH
When the massive tsunami hit the Indian Ocean two years ago and killed nearly a quarter of a million people, Israelis said that was one problem that wouldn't hit them.
But research conducted by Dr. Amos Salamon of the Geological Survey of Israel and colleagues in Italy and the US will report on Thursday that since before the Common Era, there have been two dozen tsunamis documented in the region and 11 on Israel's coasts.
The research will be presented in a lecture at the Weizmann Institute of Science in Rehovot to mark the annual Planet Earth Day sponsored by the nonprofit Israel Geological Society.
Salamon and researchers at the University of California-Santa Cruz and Storia Geofisica Ambiente in Bologna said that even though Israel faces the Mediterranean Sea and not a major ocean, tsunamis do occur.
The Talmud itself mentions a tsunami between Caesarea and Yavne on December 12 in the year 115 CE after a major earthquake hit northwest Syria.
The term tsunami was created by Japanese fishermen who returned to port to find the area surrounding their harbor devastated, although they had not been aware of any wave in the open water. Tsunamis (from the Japanese word "tsu" meaning harbor and "nami" meaning wave) are common throughout Japanese history, with nearly 200 events recorded there.
The researchers said a tsunami caused by an earthquake in the region could cause waves of one to three meters in height, and if the seabed shifted, it could reach six meters. The waves could reach the coast in only a few minutes if the seabed shifted, but it could take between half an hour and an hour if the source is Cyprus or the Aegean Sea.
A tsunami early-warning system, if and when it is installed, has to take into account a variety of mechanisms that can cause tidal waves and the various distances from Israel where the geological shocks originate.
In most cases, the researchers said, when the shock was close, the best early-warning system would be the earthquake itself. In those cases when the sea actually recedes, this is an additional warning of a coming tsunami. The team agreed that more research must be conducted into the phenomenon.
Salamon and colleagues carried out a historical survey of tsunamis in the eastern Mediterranean based on scientific and historical reports. They said some of the reported tsunamis were entered into catalogues "apparently in error for all sorts of reasons, and thus there may be an impression that the danger is more serious than it really is."
At the request of the inter-ministerial steering committee in preparation for an earthquake in Israel and after the devastating damage caused in the Indian Ocean in December 2004, the team decided to reassess the dangers of tsunamis on the coast of Israel.
They looked both at reports of tsunamis in the eastern Mediterranean and of earthquakes as far west as southern Turkey, Cyprus, Greece and Italy.
The first recorded tsunami in the region was in Egypt in the 14th century BCE, documented by archeological findings, the team said. A tsunami hit Israel's coast on the average of once every 200 years, with the last recorded once on November 25, 1759; this affected the coast of Israel and the Nile Delta and was caused by an earthquake on the border between Syria and Lebanon.
Seismic gushes of water have also been documented in the Kinneret, the Dead Sea and the Gulf of Eilat.