More details of the Soufrière Hills lava dome collapse of 11 February 2010 22 February 2010Posted by admin in activity reports, Caribbean, Soufrière Hills.
Tags: Caribbean, Montserrat, Soufrière Hills, volcanic activity reports
The Montserrat Volcano Observatory has released more details of the dome collapse that took place at Soufrière Hills volcano on 11 February 2010. The pyroclastic flows generated by the collapse felled many trees and levelled buildings (in evacuated areas) to the north-east of the volcano, and extended the coastline by 650 m, and some of the flow deposits have a thickness of 15 m. The collapse has left a deep collapse scar on the northern side of the summit, and the MVO reports that ‘It is currently unclear whether there is a new dome growing inside the crater’.
The Soufrière Hills activity bulletin issued by MVO for 12-19 February gives more detail on some aspects of the 11 February event. The collapse scar on the volcano’s northern flank is reported to be approximately 300 m wide, and there is a separate crater of similar diameter at the summit of the lava dome. A temperature of 470 degrees centigrade was measured at one place on the pyroclastic flow deposits on 15 February, and the MVO notes that ‘these deposits will retain such high temperatures for months’. As for new dome growth, ‘It is at present unclear whether there is any new dome growth within the crater. However FTIR (Fourier Transform Infrared) measurements on the afternoon of the 17 February gave a hydrochloric acid /sulphur dioxide ratio of 0.76, which is consistent with quite slow extrusion of lava on that day’.
Photographs of the dome collapse and aftermath can be found at the MVO’s excellent Flickr pages.
For all our Soufrière Hills coverage: Soufrière Hills « The Volcanism Blog.