Evidence of ancient tsunami uncovered on Israeli coast

Dec. 23 (UPI) -- Using a combination of geological and archaeological analyses, researchers have uncovered evidence that a massive paleo-tsunami struck Israel's Mediterranean coast, near the ancient settlement of Tel Dor, between 9,910 and 9,290 years ago.

Scientists detailed their discovery in a new paper, published Wednesday in the journal PLOS One.

'Paleo-tsunami' is the term given to tsunamis that occurred prior to the historical record. Both geologic and historical records suggest the eastern Mediterranean has been struck by a tsunami about once every century over the last 6,000 years.

Tel Dor was an ancient maritime settlement occupied from the Middle Bronze Age, beginning around 2000 B.C., through the Crusades, around 1100 A.D. The settlement was positioned along what's now the northwest coast of Israel.

While studying the geography of the ancient settlement, creating a digital model of the site using underwater excavations and borehole digging, researchers discovered an abrupt layer of marine sediment they surmised had been deposited by an early Holocene tsunami.

"Our project focuses on reconstructing ancient climate and environmental change over the past 12,000 years along the Israeli coast; and we never dreamed of finding evidence of a prehistoric tsunami in Israel," lead study author Gilad Shtienberg said in a news release.

"Scholars know that at the beginning of the Neolithic, around 10,000 years ago, the seashore was [2.5 miles] from where it is today," said Shtienberg, a postdoctoral researcher at the Scripps Center for Marine Archaeology at the University of California-San Diego.

"When we cut the cores open in San Diego and started seeing a marine shell layer embedded in the dry Neolithic landscape, we knew we hit the jackpot."

Researchers found the marine seashells and sand spread out across what was then a fresh to brackish wetland. The positioning of the displaced sediment, unlike the sediment layers positioned above and below, suggests the ancient wave was between 50 and 130 feet high.

The tsunami was powerful enough to have traveled between 1 1/2 and 2 1/2 miles inland -- much larger than later tsunamis, for which there is better documentation.

Scientists previously found evidence -- damaged cave structures -- of a Dead Sea Fault system earthquake dating to roughly the same time period as the Del Tor tsunami.

Efforts to locate the remnants of Natufian and Pre-Pottery Neolithic coastal villages, settlements dated between 10,000 and 12,000 years old, have turned up surprisingly little.

The latest research may explain why. The Del Tor paleo-tsunami likely wiped away most of the evidence of the region's earliest coastal settlements.