Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Evidence for seismogenic fracture of silicic magma
AU - Tuffen, Hugh
AU - Smith, Rosanna
AU - Sammonds, Peter
PY - 2008/5/22
Y1 - 2008/5/22
N2 - It has long been assumed that seismogenic faulting is confined to cool, brittle rocks, with a temperature upper limit of 600 °C (ref. 1). This thinking underpins our understanding of volcanic earthquakes, which are assumed to occur in cold rocks surrounding moving magma. However, the recent discovery of abundant brittle–ductile fault textures in silicic lavas2, 3, 4 has led to the counter-intuitive hypothesis that seismic events may be triggered by fracture and faulting within the erupting magma itself. This hypothesis is supported by recent observations of growing lava domes, where microearthquake swarms have coincided with the emplacement of gouge-covered lava spines5, 6, leading to models of seismogenic stick-slip along shallow shear zones in the magma7. But can fracturing or faulting in high-temperature, eruptible magma really generate measurable seismic events? Here we deform high-temperature silica-rich magmas under simulated volcanic conditions in order to test the hypothesis that high-temperature magma fracture is seismogenic. The acoustic emissions recorded during experiments show that seismogenic rupture may occur in both crystal-rich and crystal-free silicic magmas at eruptive temperatures, extending the range of known conditions for seismogenic faulting.
AB - It has long been assumed that seismogenic faulting is confined to cool, brittle rocks, with a temperature upper limit of 600 °C (ref. 1). This thinking underpins our understanding of volcanic earthquakes, which are assumed to occur in cold rocks surrounding moving magma. However, the recent discovery of abundant brittle–ductile fault textures in silicic lavas2, 3, 4 has led to the counter-intuitive hypothesis that seismic events may be triggered by fracture and faulting within the erupting magma itself. This hypothesis is supported by recent observations of growing lava domes, where microearthquake swarms have coincided with the emplacement of gouge-covered lava spines5, 6, leading to models of seismogenic stick-slip along shallow shear zones in the magma7. But can fracturing or faulting in high-temperature, eruptible magma really generate measurable seismic events? Here we deform high-temperature silica-rich magmas under simulated volcanic conditions in order to test the hypothesis that high-temperature magma fracture is seismogenic. The acoustic emissions recorded during experiments show that seismogenic rupture may occur in both crystal-rich and crystal-free silicic magmas at eruptive temperatures, extending the range of known conditions for seismogenic faulting.
KW - volcano
KW - volcanic earthquake
KW - volcano seismicity
KW - fracture
KW - rupture
KW - brittle-ductile
KW - glass transition
KW - lava
KW - magma
KW - lava dome
KW - prediction
KW - earthquake
KW - hybrid event
KW - volcano-tectonic
KW - conduit
KW - obsidian
KW - andesite
KW - dacite
KW - experiment
KW - deformation
KW - acoustic emission
KW - frequency content
KW - faulting
KW - trigger mechanism
KW - high temperature failure
UR - http://www.scopus.com/inward/record.url?scp=44349112830&partnerID=8YFLogxK
U2 - 10.1038/nature06989
DO - 10.1038/nature06989
M3 - Journal article
VL - 453
SP - 511
EP - 514
JO - Nature
JF - Nature
SN - 0028-0836
IS - 7194
ER -