Satellite data reveal two separate magma reservoirs beneath Nicaragua's Masaya volcano

A team from Penn State examined Sentinel-1 interferometric SAR data collected between 2018 and 2024 and detected contrasting ground motions at Masaya volcano in Nicaragua. The broader caldera area transitioned from subsidence to uplift, a pattern the authors interpret as magma replenishment of a deep reservoir. Conversely, the vicinity of the Santiago crater continued to subside throughout the period, implying depletion of a shallower magma source.

Lead author Lizzie Johnson says these findings reveal a more intricate magma system than previously recognized, which could improve eruption forecasting for the volcano that sits within 13 miles of roughly 2 million people. Continuous monitoring, she adds, is essential to distinguish normal activity from signs of heightened hazard. The research was supported by the U.S. National Science Foundation and computational resources from Penn State’s Institute for Computational and Data Sciences.