Submarine pyroclastic deposits formed during the 20th May 2006 dome collapse of the Soufrière Hills Volcano, Montserrat


Trofimovs, J., Foster, C., Sparks, R.S.J., Loughlin, S., Friant, A., Deplus, C., Porritt, L., Christopher, T., Luckett, R., Talling, P.J., Palmer, M.R. and Le Bas, T. (2012) Submarine pyroclastic deposits formed during the 20th May 2006 dome collapse of the Soufrière Hills Volcano, Montserrat. Bulletin of Volcanology, 74, (2), 391-405. (doi:10.1007/s00445-011-0533-5).

Download

Full text not available from this repository.

Description/Abstract

The 20th May 2006 lava dome collapse of the Soufrière Hills Volcano, Montserrat, had a total non-dense rock equivalent (non-DRE) collapse volume of approximately 115×106 m3. The majority of this volume was deposited into the ocean. The collapse was rapid, 85% of the mobilized volume being removed in just 35 min, giving peak pyroclastic flow flux of 66×103 m3s−1. Channel and levee facies on the submarine flanks of the volcano and formation of a thick, steep-sided ridge, suggest that the largest and most dense blocks were transported proximally as a high concentration granular flow. Of the submerged volume, 30% was deposited from the base of this granular flow, forming a linear, high-relief ridge that extends 7 km from shore. The remaining 70% of the submerged volume comprises the finer grain sizes, which were transported at least 40 km by turbidity currents on gradients of <2°. At several localities, the May 2006 distal turbidity currents ran up 200 m of topography and eroded up to 20 cm of underlying substrate. Multiple turbidites are preserved, representing current reflection from the graben margins and deflection around topography. The high energy of the May 2006 collapse resulted in longer submarine run out than the larger (210×106 m3) Soufrière Hills dome collapse in July 2003.

Item Type: Article
ISSNs: 0258-8900 (print)
1432-0819 (electronic)
Subjects: Q Science > QD Chemistry
Q Science > QE Geology
Divisions: Faculty of Natural and Environmental Sciences > Ocean and Earth Science > Geochemistry
National Oceanography Centre (NERC) > Marine Geoscience
ePrint ID: 300262
Date Deposited: 20 Feb 2012 13:27
Last Modified: 14 Apr 2014 11:37
Projects:
The impact of submarine diagenesis of tephra on seawater chemistry
Funded by: NERC (NE/D004020/1)
Led by: Martin Ralph Palmer
24 July 2007 to 23 December 2009
URI: http://eprints.soton.ac.uk/id/eprint/300262

Actions (login required)

View Item View Item