Rare Clear Satellite Image Catches a Remote Volcano's Lava Lake Glowing

As Antarctic winter began to release its grip, an unusually clear satellite image revealed that Mount Michael, a stratovolcano at the center of remote Saunders Island in the South Atlantic, remains volcanically active. The image was acquired with the OLI (Operational Land Imager) on the NASA-USGS Landsat 8 satellite on August 24, 2026, and overlays a natural-color view with an infrared signal that reveals heat from a persistent lava lake in the volcano's summit crater. A plume hovering over the peak and darkened snow on its northern slopes also point to ongoing activity.

Saunders Island is one of the South Sandwich Islands, a roughly 350-kilometer (220-mile) string of small volcanic peaks formed where the South American plate subducts beneath the tiny South Sandwich plate. Because the volcanoes are so remote, scientists rely on satellite data to track their activity. An analysis of thermal anomalies spanning 30 years of Landsat, Sentinel and ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) observations led researchers to conclude that Mount Michael hosts a persistent lava lake in its summit crater, a feature shared by only a handful of other volcanoes on Earth, including Kilauea, Nyamulagira and Erta Ale.

Longer-term monitoring from NASA's MODIS (Moderate Resolution Imaging Spectroradiometer) and VIIRS (Visible Infrared Imaging Radiometer Suite) instruments, compiled through the near-real-time hot spot detection system MIROVA, indicates low-intensity activity has continued at Mount Michael for the past several years. Observations from NASA's Aura satellite also show that emissions of sulfur dioxide and other gases are common at the volcano.

The cloud-free window over Mount Michael closed quickly. One week later, when Landsat 9 passed over the island, cloudier weather had returned, and the peak's 843-meter (2,766-foot) height disturbed passing winds to produce a series of wave clouds resembling a ship's wake, a familiar phenomenon in the region. False-color imagery from NASA's Aqua satellite indicates a volcanic track caused by degassing sulfur dioxide was likely present as well.