Thursday 7 November 2013

Eruptions on Mount Zhupanovksy.

On Wednesday 23 October 2013 the Kamtchatka Volcanic Eruption Response Team reported a thermal anomaly appearing on Mount Zhupanovsky on the southeastern Kamtchatka Peninsula in the Russian Far East, the first activity recorded on the volcano since 1959. The following day a series of phreatic eruptions (explosions caused by ice or water encountering hot lava or other volcanic material and vaporizing) occurred on the volcano, followed by a major eruption producing a 5 km high ash column, which drifted 40 km to the southeast. Ashfalls as deep as 10 cm were recorded close to the volcano, and an aviation alert was issued. Three further ash columns were produced on the next day, followed by a bout of fumarolic activity (gas emissions) on 27 October, and a return to apparent inactivity.

Fumaroles on Mount Zhupanovsky on 26 October 2013. Sergey Samoilenko/Institute of Volcanology and Seismology at the Far Eastern Branch of the Russian Academy of Sciences.

On Tuesday 5 November 2013 NASA's  Earth-Observing 1 spotted a 3000 m ash column over Mount Zhupanovsky, along with what appear to be marks in the snow caused by further phreatic explosions, suggesting that the volcano has not yet completed this episode of activity.

Satellite image of Zhupnovsky taken on 5 November 2013. Ash column is in center of volcano and not clearly visible. Note ash lying on top of snow in lower half of image. NASA/Earth Observatory.

The Kamchatka Peninsula lies on the eastern edge of the Okhotsk Plate, close to its margin with the Pacific and North American Plates. The Pacific Plate is being subducted along the margin, and as it does so it passes under the southern part of the Kamchatka Peninsula, and as it does so is partially melted by the friction and the heat of the Earth's interior. Some of the melted material then rises through the overlying Okhotsk Plate as magma and fueling the volcanoes of southern Kamchatka.

The approximate location of Mount Zhupanovsky. Google Maps.

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