Shivelyuch (also called Shiveluch), the most northerly active volcano on the Kamchatka Peninsula, is one of the most active volcanoes in the world. On a near-daily basis, satellites detect new signs of activity within its horseshoe-shaped caldera, including thermal anomalies, hot avalanches and debris flows, and ash deposits that darken the surrounding landscape.
The Landsat 9 satellite captured this image of the towering volcano—one of the largest and tallest on the peninsula—on April 23, 2026, a day when fresh activity left its mark on the snowy, late-spring landscape. A multi-lobed plug of viscous lava called a lava dome—appearing as a dark patch in the caldera—has been actively growing in recent months, according to reports from the Kamchatka Volcanic Eruption Response Team (KVERT). Dome-building lava is typically extruded slowly and piles up into lobed, sloped, or spine-like shapes akin to those that form when toothpaste is squeezed from a tube.
On Shivelyuch, lava domes cycle through periods of growth and collapse, frequently producing explosive bursts of ash and launching avalanches of hot ash and soil called pyroclastic flows when they collapse. Debris slides through structures that Alina Shevchenko, a volcanologist with the GFZ Helmholtz Centre for Geosciences, called “avalanche chutes” and “lahar channels” radiating outward from the caldera. Collapses can trigger events geologists call “block-and-ash flows,” which typically contain coarse, blocky chunks of cooled volcanic rock along with powdery volcanic ash and soil.
Such flows often produce thick, insulating deposits that retain heat for long periods, sometimes even months or years, melting snow in the winter months. As seen in the Landsat images above, this activity leaves dark channels and exposed patches that contrast with the surrounding snow cover.
Satellites have regularly detected thermal anomalies within th …