Friday 17 May 2013

Eruption on Mount Pavlof.

Mount Pavlof, a volcano on the Alaskan Peninsula, began erupting at about 8.00 am local time (4.00 pm GMT) on Monday 13 May 2012, for the first time since 2007, according to the Alaska Volcano Observatory, which detected a sharp rise in seismic activity combined with a strong thermal signal detected by Satellite. The following day aerial observations recorded seeing fresh lava on the flanks of the mountain and small amounts of steam and ash emitting from the crater. On 15 May a fresh round of seismic activity was accompanied by a column of ash and steam that rose 6000 above the summit, and incandescence around the crater that could be seen from Cold Bay, 60 km to the southwest. This has persisted, drifting 100 km to the southeast on 16 May. Fountains of lava have also been observed, and lava is reported to be flowing on the volcano's northwest flank.

Eruption on Pavlof Volcano, 16 May 2013. Rachel Kremer/Alaska Volcano Observatory/AP.

Pavlof is a 2500 m high, 7 km wide stratovolcano (cone-shaped volcano) between Cold Bay and Pavlof Bay near the tip of the Alaskan Peninsula. It has several active vents on its north and east flanks, it's remoteness and inaccessibility meaning that it is usually hard to tell from exactly which of these an individual eruption is occurring. Pavlof is considered to be one of America's most active volcanoes, and though it is located in a remote spot with no settlement close by, it still presents a serious threat to air-traffic.

The volcanoes of the Alaskan Peninsula and Aleutian Islands are fed by magma rising from the Pacific Plate, which is being subducted beneath the North American Plate to the south. As the subducting plate sinks into the Earth it is subjected to enormous heat and pressure, causing more volatile minerals to melt. These then rise through the overlying North American plate as magma, fueling the Alaskan volcanoes.

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