London, May 4 (ANI): Scientists have come up with a scenario that suggests a huge tsunami crashed into the New York City region 2,300 years ago, dumping sediment and shells across Long Island and New Jersey and casting wood debris far up the Hudson River.
According to a report by BBC News, Steven Goodbred, an Earth scientist at Vanderbilt University, said that it may have been a large storm, but evidence is increasingly pointing to a rare Atlantic Ocean tsunami.
He said that large gravel, marine fossils and other unusual deposits found in sediment cores across the area date to 2,300 years ago.
The size and distribution of material would require a high velocity wave and strong currents to move it, and it is unlikely that short bursts produced in a storm would suffice, he explained.
"If we're wrong, it was one heck of a storm," said Goodbred.
According to Goodbred, the New York wave was on the Grand Banks scale - three to four metres high and big enough to leap over the barrier islands; but that it did not reach the magnitude of the 2004 Sumatran tsunami.
He first proposed the link between the layers of unusual debris found in sediment cores and a tsunami while studying shellfish populations in Great South Bay, Long Island.
He extracted many mud cores with incongruous 20cm layers of sand and gravel.
Their age matched that of wood deposits buried in the Hudson riverbed and marine fossils in a New Jersey debris flow in cores gathered by other researchers.
"The fist-sized gravel he found in Long Island would require a high velocity of water - well over a metre per second - to land where it did," said Goodbred.
Among the fossils and shells sandwiched in the organic black mud of Sandy Hook Bay, New Jersey, Marine Geologist Cecilia McHugh of Queens College, City University of New York, discovered mud balls made from red clay that matched iron-rich sediments found onshore.
"The balls form their spherical shape only through vigorous reworking, and they do not form in small storms," said Dr McHugh.
"I didn't think much about it until we dated the deposit and came up with the same date that Steve did on Long Island," she said.
According to Driscoll, to rule out the possibility of a severe storm, tsunami groups should collect more core samples to see whether the distribution of the debris is consistent. (ANI)