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Fourpeaked Mountain volcano, Alaska: news
Saturday, Nov 11, 2006
Low-level earthquake activity continues at Fourpeaked volcano. Web camera views this past week show a typical steam plume rising several hundred meters above the summit. ...more [ read all]
Thursday, Oct 26, 2006
The AVO reported that earthquake activity and gas emissions continued at Fourpeaked during 14-20 October. Steam-and-gas plumes rising from a location near the summit were visible on a recently installed web camera. [ read all]
Sunday, Oct 15, 2006
The AVO reported that volcanic unrest continued at Fourpeaked during 30 September-6 October. A seismometer that was installed on 25 September indicated ongoing low-level seismicity. Due to the limited number of seismometers, earthquake epicenters were not located. Emission rates of sulfur dioxide were high, similar to the previous week. [ read all]
Saturday, Feb 26, 2005
 Aerialphoto of the summit of Fourpeaked volcano on an overflight on the 24th of Sep 2006 showing several steaming vents on its summit. (Photo courtesy: Cyrus Read, AVO/USGS) The first known historic eruption of Fourpeaked volcano on the Alaska peninsula is taking its course. Several vents emitting gasses and ash have appeared on the glacier-topped volcano and are slowly melting the ice cap. ...moreOn September 17, an explosion of ash, gas, and steam from Fourpeaked Mountain 320 km (200 mi) SW of Anchorage on the Alaska Peninsula marked the onset of unrest at this long-dormant, ice-clad volcano. AVO elevated the level of concern color code to YELLOW on September 20. Since then, AVO has gathered aerial and ground-based information and also initiated installation of geophysical instrumentation to better track activity at Fourpeaked. Based on our observations and limited geologic understanding of the volcano, it is possible that significant eruptive activity could occur in the coming days to weeks.
Over the weekend and continuing today, AVO flew a variety of missions to Fourpeaked volcano. The main findings are as follows: (1) Observers saw a linear series of vents running north from the summit for about 1 km (0.6 mi). Most of these vents were vigorously emitting steam and other volcanic gasses. In the immediate vicinity of the vents, the glacier had been disrupted and showed signs of subsidence. (2) Gas measurements reveal that emission rates of sulfur dioxide, hydrogren sulfide, and carbon dioxide were all high. The sulfur dioxide emission rate was roughly equivalent to that measured at Augustine before its January 2006 eruptions. A distinct sulfur smell was evident up to 50 km (30 mi) from Fourpeaked's summit. (3) Marked scouring of a glacier flowing west from the summit indicates flooding, probably from the September 17th event. [ less] [ read all]
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