Indonesia cave reveals history of ancient tsunamis
Posted onDecember 27, 2013
A cave discovered near the source of Indonesia’s massive earthquake-spawned tsunami contains the footprints of past gigantic waves dating up to 7,500 years ago, a rare natural record that suggests the next disaster could be centuries away—or perhaps only decades.
The findings provide the longest and most detailed timeline for tsunamis that have occurred off the far western tip of Sumatra island in Aceh province. That’s where 100-foot (30-meter) waves triggered by a magnitude-9.1 earthquake on Dec. 26, 2004, killed 230,000 people in several countries, more than half of them in Indonesia.
The limestone cave, located within a couple hundred yards (meters) of the coast near Banda Aceh, is about 3 feet (1 meter) above knee-high tide and protected from storms and wind. Only huge waves that inundate the coastal area are able to gush inside.