Lava flow, phreatic bursts and collapse of loose slag material at Klyuchevskoy volcano, Russia

A moderate explosive-effusive eruption continues at Russian Klyuchevskoy volcano with Strombolian and sometimes Vulcanian activity observed. The Aviation Color Code remains Orange.

The lava flow first observed on April 18 continues to move on the southeastern flank of the volcano (the Apakhonchich chute), accompanied by phreatic bursts and collapse of loose slag material, KVERT reported at 04:24 UTC on April 27, 2020.

Klyuchevskoy volcano on April 27, 2020. Image credit: Copernicus EU/Sentinel-2, Antonio Vecoli

Klyuchevskoy volcano on April 27, 2020. Image credit: Copernicus EU/Sentinel-2, Antonio Vecoli

According to satellite data, ash plume is extending about 424 km (263 miles) to the west of the volcano and rising up to 6 000 m (19 700 feet) above sea level.

A moderate explosive eruption of the volcano continues. Ash explosions up to 5 – 7 km (16 400 – 23 000 feet) a.s.l. could occur at any time. Ongoing activity could affect low-flying aircraft.

Geological summary

Klyuchevskoy (also spelled Kliuchevskoi) is Kamchatka's highest and most active volcano. Since its origin about 6 000 years ago, the beautifully symmetrical, 4 835-m-high (15 862 feet) basaltic stratovolcano has produced frequent moderate-volume explosive and effusive eruptions without major periods of inactivity. It rises above a saddle NE of sharp-peaked Kamen volcano and lies SE of the broad Ushkovsky massif.

More than 100 flank eruptions have occurred during the past roughly 3 000 years, with most lateral craters and cones occurring along radial fissures between the unconfined NE-to-SE flanks of the conical volcano between 500 m and 3 600 m (1 640 – 11 811 feet) elevation.

The morphology of the 700-m-wide (2 296 feet) summit crater has been frequently modified by historical eruptions, which have been recorded since the late-17^th century. Historical eruptions have originated primarily from the summit crater, but have also included numerous major explosive and effusive eruptions from flank craters. (GVP)

Featured image credit: Lava flow at Klyuchevskoy volcano on April 27, 2020. Credit: Copernicus EU/Sentinel-2. Processed by Antonio Vecoli