Regional Industry & News

A volcano that is almost always hidden by clouds showed up clearly from orbit near the end of the austral winter. NASA released imagery through its Earth Observatory on September 7 showing heat from the lava lake in Mount Michael's summit crater, captured on August 24 during an uncommonly clear break in the weather over Saunders Island in the South Atlantic.

The image stands out for two reasons. Lava lakes that stay active for long periods are rare, and NASA counts only a handful of other volcanoes on Earth with similarly frequently active features. Mount Michael also sits on a remote island where the clouds so seldom part that satellites supply much of what scientists know about its behavior.

For readers in the United States, the relevance lies in the method. Scientists watching remote Alaskan volcanoes also lean on satellite views, and the same cloud problem that hides Mount Michael shapes what they can see.

One of Only a Handful of Frequently Active Lava Lakes

A lava lake is a body of molten rock that stays exposed in a crater instead of draining away or crusting over completely. Keeping one active requires a steady supply of hot magma reaching the surface, which is why few volcanoes sustain lava lakes for long.

NASA's caption for the August image states that Mount Michael "hosts a frequently active lava lake in its summit crater." NASA lists Kīlauea in Hawaii, Nyamulagira in the Democratic Republic of the Congo and Erta Ale in Ethiopia among the small group of volcanoes known to have similar features.

Satellites made the case first. A peer-reviewed analysis of three decades of satellite data, published in 2019 in the Journal of Volcanology and Geothermal Research by a team led by D.M. Gray, examined thermal anomalies in Landsat, Sentinel-2 and ASTER observations and concluded that Mount Michael hosts a persistent lava lake. Ground confirmation came later. In November 2022, an expedition led by University College London volcanologist Emma Nicholson made the first ascent of the volcano and confirmed the lava lake in its crater, according to UCL.

Infrared Bands Reveal the Heat Signal

The August 24 image came from the Operational Land Imager on the NASA-USGS Landsat 8 satellite. It is a natural-color scene overlaid with an infrared signal from OLI bands 7, 6 and 5, shown in red, that reveals heat from the lava lake.

Two other clues appear in the same frame. A small volcanic plume hovers over the peak, and snow on the northern slopes is darkened. NASA said both suggest ongoing activity, although neither would confirm an eruption on its own.

Longer-term tracking relies on instruments that pass over more often. NASA noted that thermal observations from the MODIS and VIIRS instruments have enabled long-term monitoring of Mount Michael, and data from MIROVA, a near-real-time volcanic hot spot detection system, indicate that low-intensity activity has continued for the past several years. Observations from NASA's Aura satellite show that emissions of sulfur dioxide and other gases are common there.

Saunders Island is one of the South Sandwich Islands, a chain of small volcanic peaks about 350 kilometers, or 220 miles, long that formed as the South American plate subducts beneath the small South Sandwich plate. Eruptions have occurred regularly on the islands in recent centuries, including at Mount Michael.

About a Week Later, the Clouds Returned

The clear view did not last. When Landsat 9 passed over on September 1, a more active atmosphere had returned, and NASA's second image shows a series of V-shaped wave clouds trailing downwind of the island.

The clouds form when the 843-meter, or 2,766-foot, peak disturbs passing winds. NASA compared the pattern to the wake of a ship and called it a familiar phenomenon in the region. False-color imagery from NASA's Aqua satellite also indicates that a volcanic track, a cloud modification caused by sulfur dioxide degassing, was likely present.

The eight-day sequence is a realistic picture of remote volcano monitoring: one usable thermal observation, followed by a view in which the weather, not the volcano, dominates the scene.

Alaska's Volcano Monitors Face the Same Cloud Problem

This constraint also affects U.S. hazard monitoring. The most recent Smithsonian and USGS Weekly Volcanic Activity Report, covering August 27 through September 2, shows it directly. The Alaska Volcano Observatory reported that slow lava effusion continued to feed a thick flow in Great Sitkin's summit crater, that the flow gradually expanded east, and that minor earthquakes were detected daily, likely associated with rockfalls on the growing dome. Weather clouds obscured webcam and satellite views during most of the week. Great Sitkin remained at Volcano Alert Level Watch, the third level on a four-level scale, and Aviation Color Code Orange, the third color on a four-color scale.

The daily earthquake detections in that report show why observatories do not depend on a single data stream. When clouds block the view, seismic and other ground-based data still offer a read on activity. When a volcano update seems vague about surface conditions, cloud cover is often the reason.

The Next Look Depends on Weather and Orbit

There is no scheduled next observation of Mount Michael. Landsat 8 and Landsat 9 will pass over on their regular repeat cycles, and whether they return anything useful depends on whether the sky clears. MIROVA's near-real-time system will continue to log thermal detections when conditions allow.

Nature World News will watch for changes in the MIROVA record and for any Smithsonian weekly report entry on Saunders. For now, this is a science and monitoring story rather than a hazard story. Saunders Island has no permanent population, and the value of the imagery lies in what it shows about a rare volcanic feature and about the limits of watching Earth from orbit.

What Readers Want to Know

What did NASA actually release? Two Landsat images of Saunders Island. One, acquired by Landsat 8 on August 24, 2026, includes an infrared overlay showing heat from the summit lava lake. The other, acquired by Landsat 9 on September 1, 2026, shows wave clouds forming downwind of the peak.

What is a lava lake? Molten rock that remains exposed in a volcanic crater rather than draining away or cooling over completely. Sustaining one requires a steady supply of hot magma, which is why only a handful of volcanoes are known to host frequently active lava lakes.

Where is Mount Michael? On Saunders Island in the South Sandwich Islands, a remote volcanic chain in the South Atlantic. The summit reaches 843 meters, about 2,766 feet.

Is anyone in danger? No. The island has no permanent population, and the imagery concerns scientific monitoring rather than a public hazard.

How do scientists know the lava lake exists? A 2019 study of about 30 years of satellite thermal data concluded that Mount Michael hosts a persistent lava lake. In November 2022, a UCL-led expedition made the first ascent of the volcano and confirmed the lake on the ground.

Does this matter for U.S. volcano monitoring? Yes, as a method. Remote American volcanoes such as Great Sitkin in the Aleutians are frequently hidden from webcams and satellites by clouds, so observatories combine visual data with seismic and other ground-based monitoring.

When will there be another clear image? There is no set date. It depends on clear skies coinciding with a satellite overpass. Thermal detection systems continue reporting when conditions allow.