The house-sized boulders were likely flung ashore by a wave rivaling the 1883 Krakatau tsunami, which is estimated to have towered 35 meters (115 feet) high.
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©M. Hornbach |
Tongatapu boulder. |
"These could be the largest boulders displaced by a tsunami, worldwide," says Matthew Hornbach of the University of Texas Institute for Geophysics. "Krakatau's tsunami was probably not a one-off event." Hornbach and his colleagues will discuss these findings at the Joint Annual Meeting of the Geological Society of America (GSA), Soil Science Society of America (SSSA), American Society of Agronomy (ASA), Crop Science Society of America (CSSA), and the Gulf Coast Association of Geological Societies (GCAGS), in Houston, Texas, USA.*