According to Halifax scientist Alan Ruffman, one of the clues lies in the ancient dialect of Tamil, which had its own phrase for destructive waves triggered by earthquakes. Another evidence lies in the layers below the Earth's surface. "Coastal sediments provide a potent geological record of recent and ancient tsunamis," said Ruffman, adding that the size of the sand particles can provide clues about the actual height of the water column. As further proof, Ruffman has a compelling photo of a research colleague at a dig in Thailand, showing four distinct bands of sand.
The surface layer was deposited by the 2004 tsunami, and Ruffman figured out that the next layer was left by an event dating back 400 to 600 years. "The tsunami that laid that one down was probably about the same size as the one in 2004," he said.
As part of the efforts to help people in Southeast Asia better prepare for the next monster wave, the Shastri Indo-Canadian Institute, has awarded a seed grant to help Dalhousie develop a tsunami research partnership with the University of Madras in Chennai, India.
The research would involve in-depth study of the history of tsunamis in the Bay of Bengal. This will range from detailed geological sediment studies to analysis of southern India's early writings and folklore, to find human accounts of early tsunamis.
"There are more than 1,500 unanalyzed early documents in the Tamil language that stretch back one to two thousand years," said Ruffman.
According to Ruffman, "If the Tamil Nadu sediments tell a similar story to the layers shown in the striking photo from Thailand, then our scientific team should be able to put a solid estimate on the return period of such devastating events,"
"This would allow communities and governments to put in place the necessary tsunami warning systems and evacuation procedures for future events," he added.
It could go much further than that, with such proactive steps as restoring mangrove vegetation, to help prevent tsunami erosion along coastlines, and even moving whole villages to safer locations.
"If the understanding of the very real and present tsunami hazard leads to better location of coastal villages, housing and infrastructure, then the financial and human losses during future tsunamis will be greatly reduced," said Ruffman.