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An overview of lava dome evolution, dome collapse and cyclicity at Soufrière Hills Volcano, Montserrat, 2005–2007
Author(s) -
Loughlin S. C.,
Luckett R.,
Ryan G.,
Christopher T.,
Hards V.,
De Angelis S.,
Jones L.,
Strutt M.
Publication year - 2010
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2010gl042547
Subject(s) - dome (geology) , geology , lava dome , volcano , magma , lava , seismology , electrical conduit , slip (aerodynamics) , geomorphology , thermodynamics , mechanical engineering , physics , engineering
The third episode of lava dome growth at Soufrière Hills Volcano, Montserrat was characterised by higher average magma discharge rates than either previous dome growth episode at this volcano and yet fewer collapses. During sustained dome growth at moderate‐high average rates (>6 m 3 /s), we identified 2–6 week discharge pulses that each supplied c.20 Mm 3 magma from depth. Our observations are consistent with some existing models but we explain discrepancies by a combination of higher volatile contents and higher ascent rates. Cycles of c. 11–16 days were evident in rockfall, LP rockfall and shallow LP earthquake counts related to dome growth and degassing. We speculate that degassing at the conduit margins together with stick‐slip conduit flow may drive these cycles. Only one major collapse >10 Mm 3 occurred during the third episode (on May 20, 2006) as a new magma pulse entered the dome and coincided with heavy rainfall.