Classification and idealized limit-equilibrium analyses of dome collapses at Soufrière Hills volcano, Montserrat, during growth of the first lava dome: November 1995-March 1998

John Simmons, Derek Elsworth, Barry Voight

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Styles of dome collapse at Soufrière Hills volcano (SHV; November 1995-March 1998) are classified by relations between extrusion rate prior to collapse and collapse volume. Four separate modes of collapse behavior are apparent. Notably, moderate rates of extrusion are shown to result in two disparate modes of collapse: small-to-large collapses on steeply inclined failure planes that switch to collapse volumes an order of magnitude larger that cut deeply into the dome core. For constant effusion rates, this bifurcation in behavior is explained by the monotonic growth of a soft core that ultimately promotes the development of a deep-seated failure over previously favored shallow failure modes. Models are developed to test this hypothesis that first constrain magnitudes of cohesive and frictional strength with observed dome collapse morphologies and volumes. Evaluations of dome strengths confirm the important role of a soft core in promoting deep failure. A nested model representing a cohesive dome core, surrounded by a frictional rind, with constant rate of magma input, confirms the observed bifurcation in behavior, and for invariant effusive activity. Importantly, failure volumes are shown to increase by close to an order of magnitude for a few percent change in the proportion of dome core comprising cohesive material. This model is capable of replicating, a posteriori, the approximate timing of failure for both small (250 m) and large (325 m) domes. The timing and style of the 17 September 1996 and June to November 1997 collapses are honored.

Original languageEnglish (US)
Pages (from-to)241-258
Number of pages18
JournalJournal of Volcanology and Geothermal Research
Volume139
Issue number3-4
DOIs
StatePublished - Jan 15 2005

Fingerprint

lava dome
Volcanoes
Domes
lava
domes
volcanoes
dome
volcano
Extrusion
bifurcation
extrusion
time measurement
Failure modes
failure modes
Switches
magma
proportion
switches
rate
evaluation

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Geochemistry and Petrology

Cite this

@article{021dd3eddff144d89f5c72501c5261ea,
title = "Classification and idealized limit-equilibrium analyses of dome collapses at Soufri{\`e}re Hills volcano, Montserrat, during growth of the first lava dome: November 1995-March 1998",
abstract = "Styles of dome collapse at Soufri{\`e}re Hills volcano (SHV; November 1995-March 1998) are classified by relations between extrusion rate prior to collapse and collapse volume. Four separate modes of collapse behavior are apparent. Notably, moderate rates of extrusion are shown to result in two disparate modes of collapse: small-to-large collapses on steeply inclined failure planes that switch to collapse volumes an order of magnitude larger that cut deeply into the dome core. For constant effusion rates, this bifurcation in behavior is explained by the monotonic growth of a soft core that ultimately promotes the development of a deep-seated failure over previously favored shallow failure modes. Models are developed to test this hypothesis that first constrain magnitudes of cohesive and frictional strength with observed dome collapse morphologies and volumes. Evaluations of dome strengths confirm the important role of a soft core in promoting deep failure. A nested model representing a cohesive dome core, surrounded by a frictional rind, with constant rate of magma input, confirms the observed bifurcation in behavior, and for invariant effusive activity. Importantly, failure volumes are shown to increase by close to an order of magnitude for a few percent change in the proportion of dome core comprising cohesive material. This model is capable of replicating, a posteriori, the approximate timing of failure for both small (250 m) and large (325 m) domes. The timing and style of the 17 September 1996 and June to November 1997 collapses are honored.",
author = "John Simmons and Derek Elsworth and Barry Voight",
year = "2005",
month = "1",
day = "15",
doi = "10.1016/j.jvolgeores.2004.08.009",
language = "English (US)",
volume = "139",
pages = "241--258",
journal = "Journal of Volcanology and Geothermal Research",
issn = "0377-0273",
publisher = "Elsevier",
number = "3-4",

}

TY - JOUR

T1 - Classification and idealized limit-equilibrium analyses of dome collapses at Soufrière Hills volcano, Montserrat, during growth of the first lava dome

T2 - November 1995-March 1998

AU - Simmons, John

AU - Elsworth, Derek

AU - Voight, Barry

PY - 2005/1/15

Y1 - 2005/1/15

N2 - Styles of dome collapse at Soufrière Hills volcano (SHV; November 1995-March 1998) are classified by relations between extrusion rate prior to collapse and collapse volume. Four separate modes of collapse behavior are apparent. Notably, moderate rates of extrusion are shown to result in two disparate modes of collapse: small-to-large collapses on steeply inclined failure planes that switch to collapse volumes an order of magnitude larger that cut deeply into the dome core. For constant effusion rates, this bifurcation in behavior is explained by the monotonic growth of a soft core that ultimately promotes the development of a deep-seated failure over previously favored shallow failure modes. Models are developed to test this hypothesis that first constrain magnitudes of cohesive and frictional strength with observed dome collapse morphologies and volumes. Evaluations of dome strengths confirm the important role of a soft core in promoting deep failure. A nested model representing a cohesive dome core, surrounded by a frictional rind, with constant rate of magma input, confirms the observed bifurcation in behavior, and for invariant effusive activity. Importantly, failure volumes are shown to increase by close to an order of magnitude for a few percent change in the proportion of dome core comprising cohesive material. This model is capable of replicating, a posteriori, the approximate timing of failure for both small (250 m) and large (325 m) domes. The timing and style of the 17 September 1996 and June to November 1997 collapses are honored.

AB - Styles of dome collapse at Soufrière Hills volcano (SHV; November 1995-March 1998) are classified by relations between extrusion rate prior to collapse and collapse volume. Four separate modes of collapse behavior are apparent. Notably, moderate rates of extrusion are shown to result in two disparate modes of collapse: small-to-large collapses on steeply inclined failure planes that switch to collapse volumes an order of magnitude larger that cut deeply into the dome core. For constant effusion rates, this bifurcation in behavior is explained by the monotonic growth of a soft core that ultimately promotes the development of a deep-seated failure over previously favored shallow failure modes. Models are developed to test this hypothesis that first constrain magnitudes of cohesive and frictional strength with observed dome collapse morphologies and volumes. Evaluations of dome strengths confirm the important role of a soft core in promoting deep failure. A nested model representing a cohesive dome core, surrounded by a frictional rind, with constant rate of magma input, confirms the observed bifurcation in behavior, and for invariant effusive activity. Importantly, failure volumes are shown to increase by close to an order of magnitude for a few percent change in the proportion of dome core comprising cohesive material. This model is capable of replicating, a posteriori, the approximate timing of failure for both small (250 m) and large (325 m) domes. The timing and style of the 17 September 1996 and June to November 1997 collapses are honored.

UR - http://www.scopus.com/inward/record.url?scp=10844277867&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=10844277867&partnerID=8YFLogxK

U2 - 10.1016/j.jvolgeores.2004.08.009

DO - 10.1016/j.jvolgeores.2004.08.009

M3 - Article

AN - SCOPUS:10844277867

VL - 139

SP - 241

EP - 258

JO - Journal of Volcanology and Geothermal Research

JF - Journal of Volcanology and Geothermal Research

SN - 0377-0273

IS - 3-4

ER -