Mysterious 13th Century eruption traced to Lombok, Indonesia

The caldera that is today Segara Anak Crater Lake, formed after the eruption

Scientists think they have found the volcano responsible for a huge eruption that occurred in the 13th Century.

The mystery event in 1257 was so large its chemical signature is recorded in the ice of both the Arctic and the Antarctic.

European medieval texts talk of a sudden cooling of the climate, and of failed harvests.

In the PNAS journal, an international team points the finger at the Samalas Volcano on Lombok Island, Indonesia.

Little remains of the original mountain structure - just a huge crater lake.

The team has tied sulphur and dust traces in the polar ice to a swathe of data gathered in the Lombok region itself, including radiocarbon dates, the type and spread of ejected rock and ash, tree-rings, and even local chronicles that recall the fall of the Lombok Kingdom sometime in the 13th Century.

"The evidence is very strong and compelling," Prof Clive Oppenheimer, from Cambridge University, UK, told reporters.

Co-worker Prof Franck Lavigne, from the Pantheon-Sorbonne University, France, added: "We conducted something similar to a criminal investigation.

"We didn't know the culprit at first, but we had the time of the murder and the fingerprints in the form of the geochemistry in the ice cores, and that allowed us to track down the volcano responsible."

The 1257 eruption has been variously linked with volcanoes in Mexico, Ecuador and New Zealand.

But these candidates fail on their dating or geochemistry, the researchers say. Only Samalas can "tick all the boxes".