Evidence for seismogenic fracture of silicic magma

Tuffen, Hugh and Smith, Rosanna and Sammonds, Peter (2008) Evidence for seismogenic fracture of silicic magma. Nature, 453 (7194). pp. 511-514. ISSN 0028-0836

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Abstract

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.

Item Type:
Journal Article
Journal or Publication Title:
Nature
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1000
Subjects:
?? volcanovolcanic earthquakevolcano seismicityfracturerupturebrittle-ductileglass transitionlavamagmalava domepredictionearthquakehybrid eventvolcano-tectonicconduitobsidianandesitedaciteexperimentdeformationacoustic emissionfrequency contentfaultingtrigger ??
ID Code:
9181
Deposited By:
Deposited On:
30 May 2008 13:10
Refereed?:
Yes
Published?:
Published
Last Modified:
15 Jul 2024 11:37