Masaya, Nicaragua: lava-lake volcano has two active magma reservoirs

Masaya volcano in Nicaragua, not far from the capital Managua, consists of several overlapping craters and calderas. Its Santiago crater holds an active lava lake. About 2 million people live within some 21 kilometres (13 miles) of the volcano, according to researchers at Penn State University.

A team led by Lizzie Johnson analysed satellite data (Sentinel-1) from 2018 to 2024 using InSAR, a radar method that detects tiny changes in ground elevation even through clouds. The ground in the main caldera first sank and then began to rise, possibly as new magma entered a deep reservoir. Around Santiago crater, however, the ground kept sinking, pointing to a second, shallower reservoir. The study was published in Geophysical Research Letters.

The observations show no immediate danger to nearby communities, the researchers said. Masaya's last major lava flow was in 1772. “Its persistent degassing often produces dangerously high concentrations of sulfur dioxide volcanic gas,” Johnson said.