Soufrière Hills, Montserrat: volcano news & activity updates
Soufriere Hills volcano (Montserrat): phreatic explosions suggest rising magma
Friday Mar 23, 2012 22:29 PM | BY: T
Ash venting at Soufriere Hills volcano on 23 March (Photo: MVO)New ash eruptions have occurred at Soufriere Hills volcano on Montserrat. The activity is probably phreatic in origin and caused by rising magma under the volcano.
The ash emissions began at around 8 am local time on 23 March, following 2 volcanic earthquake swarms on 22 and 23 March, the Montserrat Volcano Observatory (MVO) reports.
The vents of the new activity are on the floor of the 11 February 2010 collapse scar, immediately south of the old English’s crater wall and to the west of the long-lived hottest fumarole previously identified. Fumarolic activity on the volcano increased markedly and a new steam fumarole was discovered on the NW side of the dome immediately behind Gages Mountain.
The ash venting was pulsating and produced ash clouds reaching approx. 6000 feet above sea level (3000 feet above the volcano). At its peak, black jets of ash were seen rising a few hundred meters above the floor of the collapse scar. This type of activity is probably "phreatic" in origin, caused when superheated rock meets groundwater, which evaporates explosively and fragments rock into ash.
The volcano-tectonic earthquakes are related to fracturing rocks underneath, probably as a result of increases in pressure. It is likely that these pressure increases and the resulting earthquakes, along with the rising temperature driving the phreatic activity, are related to uprising magma below the volcano. Similar types of activity have occurred at Soufriere Hills Volcano up to several months prior to restarts in magma extrusion, for example in 2005 and 2008.
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Wednesday, Mar 14, 2012
A small pyroclastic flow occurred from Montserrat's Soufrière Hills volcano on 9 March, MVO reports. The flow was small, but happened with no warning at around 5:20 pm (local time) from the western flanks of Soufriere Hills Volcano down into Spring Ghaut. ... [more]
Thursday, Feb 02, 2012
20-27 January activity at the Soufrière Hills lava dome was at a low level. Small areas of incandescence emanated from the lava dome at night, similar to observations noted in recent months. On 27 January a small lahar descended from the W side of the lava dome. ... [more]
Friday, Jul 09, 2010
Montserrat's volcano Soufriére Hills has entered a new eruptive phase. Starting on 25 June 2010, mild ash venting has been observed from Soufriere Hills volcano. [more]
Thursday, Jun 24, 2010
The lava dome on Montserrat is again growing. The latest USGS/GVP activity report summarizes the recent activity: "MVO reported that pyroclastic flows from the Soufrière Hills lava dome occurred during 11-18 June. One of the largest pyroclastic flows traveled W down Gages Valley; others originated from within the collapse scar. A thermal camera showed several hot areas on the lava dome, likely exposed from rockfall and pyroclastic flow activity. On 28 June a small lahar descended the Belham Valley, to the NW. The Hazard Level remained at 3." [more]
Tuesday, Mar 02, 2010
According to a local observer, the possibly first pyroclastic flow from Soufrière Hills since 11 Feb was observed on 1 March 2010. The lava dome was reported glowing bright at night. [more]