Overview
- Researchers reported this week that Sentinel-1 satellite radar records from 2018–2024 show the Masaya Central Reservoir deflated about 3 cm through mid-2022 and then uplifted from mid-2022 to 2024, a pattern the team interprets as magma draining and then replenishing.
- The area around the Santiago crater kept subsiding across the same period, which the authors say points to a second, shallower reservoir roughly 200 meters below the surface that has been active concurrently.
- The paper, published in Geophysical Research Letters and led by Penn State geoscientist Lizzie Johnson, says these changes do not indicate any immediate eruption risk but that the complex plumbing warrants more long-term monitoring and modelling.
- Masaya hosts a long-lived lava lake that draws thousands of visitors and lies about 20 km from Managua, with roughly 2 million people living nearby, while persistent sulfur dioxide emissions raise local health and environmental concerns.
- The study uses roughly 12-day repeat synthetic-aperture radar to detect centimeter-scale ground movement, showing how satellite geodesy can reveal multi-reservoir magma dynamics and improve early-warning and hazard planning when paired with continued field monitoring.