Mount Samalas produced the massive 1257 eruption linked to major medieval climate cooling.
Samalas was a volcano on Lombok, Indonesia, and its catastrophic eruption in 1257 was one of the largest explosive eruptions of the last several thousand years. The eruption sent huge quantities of sulfur-rich gases into the stratosphere, where they helped form aerosols that reflected sunlight.
Historical records and tree-ring evidence show unusually cold conditions in the years after 1257. Ice cores from Greenland and Antarctica contain sulfate evidence of the eruption. Scientists identified Samalas as the source by matching the deposits’ chemical composition with volcanic rocks in Lombok.
The eruption devastated nearby communities and reshaped the volcanic landscape. Mount Rinjani now occupies the broader complex, so Samalas is sometimes incorrectly treated as simply another name for Rinjani.