Around the tsunami-prone Pacific, flood stories tell of disastrous waves that rose from the sea. Early Christian missionaries were perplexed as to why flood traditions from South Pacific islands didn’t mention the Bible’s 40 days and nights of rain, but instead told of great waves that struck without warning. A traditional story from the coast of Chile described how two great snakes competed to see which could make the sea rise more, triggering an earthquake and sending a great wave ashore. Native American stories from coastal communities in the Pacific Northwest tell of great battles between Thunderbird and Whale that shook the ground and sent great waves crashing ashore. These stories sound like prescientific descriptions of a tsunami: an earthquake-triggered wave that can catastrophically inundate shorelines without warning.
Other flood stories evoke the failure of ice and debris dams on the margins of glaciers that suddenly release the lakes they held back. A Scandinavian flood story, for example, tells of how Odin and his brothers killed the ice giant Ymir, causing a great flood to burst forth and drown people and animals. It doesn’t take a lot of imagination to see how this might describe the failure of a glacial dam.
While doing fieldwork in Tibet, I learned of a local story about a great guru draining a lake in the valley of the Tsangpo River on the edge of the Tibetan Plateau – after our team had discovered terraces made of lake sediments perched high above the valley floor. The 1,200-year-old carbon dates from wood fragments we collected from the lake sediments correspond to the time when the guru arrived in the valley and converted the local populace to Buddhism by defeating, so the story goes, the demon of the lake to reveal the fertile lake bottom that the villagers still farm.