SINGAPORE- It was the end of a long, humid summer of fieldwork, and the Indonesian and American geologists were on their way to one of their last sites of the year on the far western tip of Sumatra.
The cave was not top of the research team's list that afternoon in May 2011 but National University of Singapore anthropologist Patrick Daly, 38, an expert on the human impact of disasters, suggested they stop off at the site.
When the team of 10 cut and sliced into the cave floor, what they found amazed them.
Sandwiched between layers of bat droppings and soil were strata of sand and other deposits swept in from tsunamis that occurred over the past 7,500 years.
It was to be the longest and most detailed record yet of the natural disasters that had pummelled the Aceh coast.
Within an hour, the team recognised that the cave would merit much more work.
Over the following year or so, they mapped, surveyed and collected data, said lead researcher Charles Rubin in a phone interview with The Sunday Times.
Associate Professor Rubin, 62, is from the Earth Observatory of Singapore (EOS) at Nanyang Technological University.
Earlier this month, EOS visiting research fellow Jessica Pilarczyk presented the findings of their research at the annual American Geophysical Union meeting in San Francisco, in the United States.
The cave discovery is part of an overall effort to understand how often tsunamis and earthquakes recur at the Sunda megathrust. Aceh is located along this megathrust.