Most Recent Weekly Report: 26 October-1 November 2022 Cite this Report

Although Maly Semyachik was not erupting, KVERT raised the Aviation Color Code to Orange (the second highest level on a four-color scale) on 28 October, noting that a plume of ash, re-suspended by strong winds, was visible in satellite images drifting 123 km SE. Within three hours the Aviation Color Code was lowered back to Green. Dates are based on UTC times; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

Weekly Reports - Index

2022: October
2018: April

26 October-1 November 2022 Cite this Report

Although Maly Semyachik was not erupting, KVERT raised the Aviation Color Code to Orange (the second highest level on a four-color scale) on 28 October, noting that a plume of ash, re-suspended by strong winds, was visible in satellite images drifting 123 km SE. Within three hours the Aviation Color Code was lowered back to Green. Dates are based on UTC times; specific events are in local time where noted.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

18 April-24 April 2018 Cite this Report

KVERT reported that activity at Maly Semyachik increased during the second half of March; the ice covering the crater lake melted within a 5-6-day period, and a weak thermal anomaly was visible in satellite images. The Aviation Color Code was raised to Yellow (the second lowest level on a four-color scale) on 22 March. A weak thermal anomaly continued to be detected through 20 April, though no further activity prompted KVERT to lower the Aviation Color Code to Green.

Source: Kamchatkan Volcanic Eruption Response Team (KVERT)

The Global Volcanism Program has no Bulletin Reports available for Maly Semyachik.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Eruptive History

There is data available for 23 confirmed Holocene eruptive periods.

Deformation History

There is no Deformation History data available for Maly Semyachik.

Emission History

There is no Emissions History data available for Maly Semyachik.

Photo Gallery

The eastern margin of Karymsky caldera, which was created about 7,500 years ago, forms the steep wall across the center of the photo. Fresh, dark-colored lava flows from Karymsky cover the caldera floor. The snow-covered volcano to the NE is Maly Semyachik, which has also produced frequent historical eruptions.

Photo by Dan Miller (U.S. Geological Survey).

Maly Semiachik, seen here from the SW on the flanks of Karymsky, is composed of three overlapping edifices along a NW-SE line that were built within two overlapping Pleistocene calderas. The late-Pleistocene to Holocene post-caldera massif almost completely obscures the rim of the inner 7-km-wide Maly Semiachik caldera.

Photo by Dan Miller, 1990 (U.S. Geological Survey).

The summit of Paleo-Semyachik forms the highest point of the Maly Semyachik massif. Paleo-Semyachik, the first of three edifices constructed within two overlapping Pleistocene calderas, began forming about 20,000 years ago on the northern margin of the calderas. It produced lava flows that spread far beyond the caldera margins to the north and east before ceasing activity about 11,000 years ago. Activity then migrated to the SW, producing Meso-Semyachik volcano, whose flanks are in the foreground.

Photo by Dan Miller, 1990 (U.S. Geological Survey).

Volcanism along the elongated Maly Semiachik massif has progressively migrated to the south. The southern flank is mantled by Holocene cones and lava flows. The SE rim of a large Pleistocene caldera forms the low ridge in the background and the Pacific Ocean is visible in the distance.

Photo by Dan Miller, 1990 (U.S. Geological Survey).

An acidic lake occupies Troitsky crater, the youngest and southernmost crater of Maly Semyachik where historical eruptions have occurred. The conical peak in the distance is Karymsky, 15 km SW, which was constructed within a Holocene caldera.

Photo by Dan Miller, 1990 (U.S. Geological Survey).

A crater lake fills Troitsky crater, the youngest of six craters capping the elongated summit of Maly Semiachik volcano in central Kamchatka. Steam rises from the surface of the hot, acidic crater lake in this early 1970s photo. The lake has a maximum depth of about 140 m. Temperatures as high as 41°C have been recorded, along with pH levels down to 0.4.

Photo by Oleg Volynets (Institute of Volcanology, Petropavlovsk).

Maly Semiachik is located within several nested Pleistocene calderas and composed of three overlapping edifices along a NE-SW line. Activity migrated to the SW, eventually forming the youngest cone, Ceno-Semiachik. It contains the historically active Troitsky crater, which formed during an explosive eruption about 400 years ago. It contains a hot, acidic lake this 1972 photo.

Photo by Oleg Volynets, 1972 (Institute of Volcanology, Petropavlovsk).

The currently active Troitsky crater of Maly Semiachik formed during an explosive eruption about 400 years ago. The eastern crater wall shows light-colored hydrothermally altered rocks of the vent complex that are overlain by darker lava flows and fall deposits from eruptions that followed formation of the crater. A hot, acidic lake now fills the crater, which has been the source of historical eruptions.

Photo by Oleg Volynets (Institute of Volcanology, Petropavlovsk).

Troitsky crater, the youngest of six craters at the summit of Kamchatka's Maly Semyachik volcano, was formed during a major explosive eruption about 400 years ago. The crater, seen here from the W with the Pacific Ocean in the background, is at the summit of Ceno-Semyachik. This is the youngest of the four overlapping stratovolcanoes that comprise the Maly Semyachik massif. The crater is now filled by a hot, acidic lake and has been the source of historical eruptions.

Photo by Dan Miller, 1990 (U.S. Geological Survey).

An aerial view from the SW on 22 July 1996 shows an ash plume rising above the summit crater of Karymsky with Maly Semyachik behind it. The 1996 eruption began on 2 January simultaneously with an eruption at nearby Akademia Nauk caldera, out of view to the right. The Akademia Nauk eruption lasted only a day, but long-term eruptions continued at Karymsky.

Photo by Phillip Kyle, 1996 (courtesy of Vera Ponomareva, Institute of Volcanic Geology and Geochemistry, Petropavlovsk).

GVP Map Holdings

Maps are not currently available due to technical issues.

Smithsonian Sample Collections Database

There are no samples for Maly Semyachik in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites