Boulders on Tonga may have dumped by tsunami
WASHINGTON, Sept 24 (Reuters) - Seven monstrous chunks of coral lined up on the western shore of Tonga may be evidence of a powerful volcano-triggered tsunami, researchers said on Wednesday.
The house-sized boulders, some as high as 30 feet (9 metres) high and weighing up to 3.5 million pounds (1.6 million kg), appear to have been carried ashore several thousand years ago by a wave rivaling the tsunami generated by Indonesia's Krakatoa volcano in 1883.
"These could be the largest boulders displaced by a tsunami, worldwide," Matthew Hornbach of the University of Texas Institute for Geophysics said in a statement.
Hornbach, whose team is preparing a report on the boulders for a meeting of the Geological Society of America in Houston next month, said they are so unusual that tales of their origins appear in Tongan folklore.
According to one legend, the god Maui hurled the boulders ashore in an attempt to kill a giant human-eating fowl.
"We think studying erratic boulders is one way of getting better statistics on mega-tsunamis," Hornbach said. "There are a lot of places that have similar underwater volcanoes and people haven't paid much attention to the threat." (Reporting by Maggie Fox)
