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Report on Soufriere Hills (United Kingdom) — 31 January-6 February 2007


Soufriere Hills

Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 31 January-6 February 2007
Managing Editor: Sally Sennert.

Please cite this report as:

Global Volcanism Program, 2007. Report on Soufriere Hills (United Kingdom) (Sennert, S, ed.). Weekly Volcanic Activity Report, 31 January-6 February 2007. Smithsonian Institution and US Geological Survey.

Weekly Report (31 January-6 February 2007)

Soufriere Hills

United Kingdom

16.72°N, 62.18°W; summit elev. 915 m

All times are local (unless otherwise noted)


Based on satellite imagery, the MVO, and pilot reports, the Washington VAAC reported that a diffuse plume from Soufrière Hills rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted WNW on 31 January. Measurable activity was low and visual observations were limited due to cloud cover. On 6 January, a photograph taken from a helicopter showed that the dome had continued to grow towards the W side of the crater.

Geological Summary. The complex, dominantly andesitic Soufrière Hills volcano occupies the southern half of the island of Montserrat. The summit area consists primarily of a series of lava domes emplaced along an ESE-trending zone. The volcano is flanked by Pleistocene complexes to the north and south. English's Crater, a 1-km-wide crater breached widely to the east by edifice collapse, was formed about 2000 years ago as a result of the youngest of several collapse events producing submarine debris-avalanche deposits. Block-and-ash flow and surge deposits associated with dome growth predominate in flank deposits, including those from an eruption that likely preceded the 1632 CE settlement of the island, allowing cultivation on recently devegetated land to near the summit. Non-eruptive seismic swarms occurred at 30-year intervals in the 20th century, but no historical eruptions were recorded until 1995. Long-term small-to-moderate ash eruptions beginning in that year were later accompanied by lava-dome growth and pyroclastic flows that forced evacuation of the southern half of the island and ultimately destroyed the capital city of Plymouth, causing major social and economic disruption.

Sources: Montserrat Volcano Observatory (MVO), Washington Volcanic Ash Advisory Center (VAAC)