Samalas in Indonesia Identified as Source of the 1257 A.D. 'Missing' Eruption

The Segara Anak caldera in Indonesia -- formed by the 1257 A.D. eruption of Samalas and now the home of Rinjani and its cone, Barujari. Image: rvrastered / Flickr. The source of one of the most enigmatic eruptions over the last 10,000 years may have been conclusively identified. An eruption that occurred in 1257 or 1258 A.D. left one of the largest climate signals in the past few thousands years, producing significant sulfate spikes in the ice caps in 1258-59 and evidence from around the world of dramatic weather shifts for years afterwards. These effects looked to be on par with Tambora in 1815, but the source of such a large climate signal has been enigmatic. How do you hide an eruption that was as large as Tambora and happened less than 1000 years ago? I tried to tackle this mystery, looking at some potential sources for this massive climate signal captured in the ice cores. There were suspects, but none of them really matched perfectly. Then, in 2012, Franck Lavigne said at an American Geophysical Union Chapman Meeting of Volcanoes and the Atmosphere that a source had been identified, but didn't reveal which volcano. I did some sleuthing and made the guess that Rinjani was the volcano that was being implicated. Since then, the mystery of the 1257-58 A.D. eruption source remained.