Volcano instability induced by strike-slip faulting

Analogue sand cone experiments were conducted to study instability generated on volcanic cones by basal strike-slip movement. The results of the analogue models demonstrate that edifice instability may be generated when strike-slip faults underlying a volcano move as a result of tectonic adjustment....

Ful tanımlama

Detaylı Bibliyografya
Asıl Yazarlar: Lagmay, A, de Vries, B, Kerle, N, Pyle, D
Materyal Türü: Journal article
Dil:English
Baskı/Yayın Bilgisi: 2000
_version_ 1826292174958886912
author Lagmay, A
de Vries, B
Kerle, N
Pyle, D
author_facet Lagmay, A
de Vries, B
Kerle, N
Pyle, D
author_sort Lagmay, A
collection OXFORD
description Analogue sand cone experiments were conducted to study instability generated on volcanic cones by basal strike-slip movement. The results of the analogue models demonstrate that edifice instability may be generated when strike-slip faults underlying a volcano move as a result of tectonic adjustment. This instability occurs on flanks of the volcano above the strike-slip shear. On the surface of the volcano this appears as a pair of sigmoids composed of one reverse and one normal fault. In the interior of the cone the faults form a flower structure. Two destabilised regions are created on the cone flanks between the traces of the sigmoidal faults. Bulging, intense fracturing and landsliding characterise these unstable flanks. Additional analogue experiments conducted to model magmatic intrusion show that fractures and faults developed within the volcanic cone due to basal strike-slip motions strongly control the path of the intruding magma. Intrusion is diverted towards the areas where previous development of reverse and normal faults have occurred, thus causing further instability. We compare our model results to two examples of volcanoes on strike-slip faults: Iriga volcano (Philippines), which underwent non-magmatic collapse, and Mount St. Helens (USA), where a cryptodome was emplaced prior to failure. In the analogue and natural examples, the direction of collapse takes place roughly parallel to the orientation of the underlying shear. The model presented proposes one mechanism for strike-parallel breaching of volcanoes, recently recognised as a common failure direction of volcanoes found in regions with transcurrent and transtensional deformation. The recognition of the effect of basal shearing on volcano stability enables prediction of the likely direction of eventual flank failure in volcanoes overlying strike-slip faults.
first_indexed 2024-03-07T03:10:38Z
format Journal article
id oxford-uuid:b4134617-9b95-4d17-b91c-2eb9850918b7
institution University of Oxford
language English
last_indexed 2024-03-07T03:10:38Z
publishDate 2000
record_format dspace
spelling oxford-uuid:b4134617-9b95-4d17-b91c-2eb9850918b72022-03-27T04:23:32ZVolcano instability induced by strike-slip faultingJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:b4134617-9b95-4d17-b91c-2eb9850918b7EnglishSymplectic Elements at Oxford2000Lagmay, Ade Vries, BKerle, NPyle, DAnalogue sand cone experiments were conducted to study instability generated on volcanic cones by basal strike-slip movement. The results of the analogue models demonstrate that edifice instability may be generated when strike-slip faults underlying a volcano move as a result of tectonic adjustment. This instability occurs on flanks of the volcano above the strike-slip shear. On the surface of the volcano this appears as a pair of sigmoids composed of one reverse and one normal fault. In the interior of the cone the faults form a flower structure. Two destabilised regions are created on the cone flanks between the traces of the sigmoidal faults. Bulging, intense fracturing and landsliding characterise these unstable flanks. Additional analogue experiments conducted to model magmatic intrusion show that fractures and faults developed within the volcanic cone due to basal strike-slip motions strongly control the path of the intruding magma. Intrusion is diverted towards the areas where previous development of reverse and normal faults have occurred, thus causing further instability. We compare our model results to two examples of volcanoes on strike-slip faults: Iriga volcano (Philippines), which underwent non-magmatic collapse, and Mount St. Helens (USA), where a cryptodome was emplaced prior to failure. In the analogue and natural examples, the direction of collapse takes place roughly parallel to the orientation of the underlying shear. The model presented proposes one mechanism for strike-parallel breaching of volcanoes, recently recognised as a common failure direction of volcanoes found in regions with transcurrent and transtensional deformation. The recognition of the effect of basal shearing on volcano stability enables prediction of the likely direction of eventual flank failure in volcanoes overlying strike-slip faults.
spellingShingle Lagmay, A
de Vries, B
Kerle, N
Pyle, D
Volcano instability induced by strike-slip faulting
title Volcano instability induced by strike-slip faulting
title_full Volcano instability induced by strike-slip faulting
title_fullStr Volcano instability induced by strike-slip faulting
title_full_unstemmed Volcano instability induced by strike-slip faulting
title_short Volcano instability induced by strike-slip faulting
title_sort volcano instability induced by strike slip faulting
work_keys_str_mv AT lagmaya volcanoinstabilityinducedbystrikeslipfaulting
AT devriesb volcanoinstabilityinducedbystrikeslipfaulting
AT kerlen volcanoinstabilityinducedbystrikeslipfaulting
AT pyled volcanoinstabilityinducedbystrikeslipfaulting