Discovered in 1778 by Captain James Cook, Augustine had 10 major historic eruptions. Now 1260 m high, the height of its summit has changed frequently in the past due to dome collapse. Actually, almost every eruption Augustine’s dome collapses and subsequently a new dome is created. In 1883 a VEI 4 eruption (Volcanic Explosivity Index: http://volcanoes.usgs.gov/
Due to location of the volcano near a subduction zone, Augustine’s magma is mostly andesitic and rhyolithic in nature although during the 2006 eruption basaltic magma was also produced. Eruptions at Augustine usually start with an explosive phase that lasts for days or weeks and is followed by an effusive (characterized by effusion of lava) phase which could go on for months.
The last major eruption occurred in 2006 and was very well monitored, which could help volcanologists in their future research. Aside from minor earthquake swarms in 2007 and slight degassing from 2008-2010 the volcano has been quit. Nonetheless, it was selected as Alaska’s potentially most hazardous volcano by the USGS.
Photo: Cyrus Read, Alaska Volcano Observatory. Augustine volcano during the 2006 eruption as viewed from the ship M/V Maritime Maid.
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