Nailing down an ancient eruption.

Nailing down an ancient eruption

Atlantis' slide into the sea may have been a myth, but archaeologists long have suspected that the fable sprang from an ancient volcanic eruption on the Aegean island of Thera. One of the strongest in recorded history, this blast blew away most of the island, leaving only a crescent of the volcano's rim standing above the ocean. The eruption heralded a new phase in the bronze-age civilization of the Aegean, and archaeologists have traditionally dated the blast between 1550 BC and 1500 BC. But scientists using a 7,000-year-old sequence of tree rings are confirming evidence that suggests a date of 1628 to 1626 BC.

Researchers from Queen's University in Belfast, Ireland, report in the March 24 NATURE that oaks living in the bogs of Ireland set down narrow growth rings for the decade following 1628 BC. They reason that the Thera eruption created a globalcooling cloud of volcanic dust that affected tree growth.

This date supports previous work on a tree ring sequence from bristlecone pines in California, which indicated the same date. Dendrochronologists construct tree ring histories by using many trees whose lifespans overlap. Last year, Danish geologists dated the blast to 1645 BC plus or minus 20 years by looking for signs of the volcanic dust in the Greenland ice sheet.