UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Spatio-temporal evolution of volcano seismicity: A laboratory study

Benson, PM; Vinciguerra, S; Meredith, PG; Young, RP; (2010) Spatio-temporal evolution of volcano seismicity: A laboratory study. Earth and Planetary Science Letters , 297 (1-2) pp. 315-323. 10.1016/j.epsl.2010.06.033. Green open access

[thumbnail of Benson_EPSL2009_withFIGs_accepted.pdf]
Preview
Text
Benson_EPSL2009_withFIGs_accepted.pdf - Accepted version

Download (3MB) | Preview

Abstract

We report a laboratory and microstructural study of a suite of deformation experiments in which basalt from Mount Etna volcano is deformed and fractured at an effective confining pressure representative of conditions under a volcanic edifice (40 MPa). Particular attention was paid to the formation of a fracture and damage zone with which to stimulate coupled hydro-mechanical interactions that create the various types of seismicity recorded on volcanic edifices, and which usually precede eruption. Location of AE events through time shows the formation of a fault plane during which waveforms exhibit the typical high frequency characteristics of volcano-tectonic (VT) earthquakes. We found that these VT earthquakes were particularly pronounced when generated using dry samples, compared to samples saturated with a pore fluid (water). VT events generated during deformation of water saturated sample are characterised by a distinctive high frequency onset and a longer, low frequency coda exhibiting properties often seen in the field as hybrid events. We present evidence that hybrid events are, in fact, the common type of volcanic seismic event with either VT or low frequency (LF) events representing end members, and whose proportion depend on pore fluid being present in the rock type being deformed, as well as how close the rock is to failure. We find a notable trend of reducing instances of hybrid events leading up to the failure stage in our experiments, suggesting that during this stage, the pore fluid present in the rock moves sufficiently quickly to provide a resonance, seen as a LF coda. Our data supports recent modeling and field studies that postulate that hybrid events generated in volcanic areas are likely to be generated through the interaction of hydrothermal fluids moving through a combination of pre-existing microcrack networks and larger faults, such as those we observe in forensic (post-test) examination.

Type: Article
Title: Spatio-temporal evolution of volcano seismicity: A laboratory study
Open access status: An open access version is available from UCL Discovery
DOI: 10.1016/j.epsl.2010.06.033
Publisher version: https://doi.org/10.1016/j.epsl.2010.06.033
Language: English
Additional information: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
Keywords: Science & Technology, Physical Sciences, Geochemistry & Geophysics, volcano-tectonics, acoustic emission, rock physics, seismology, hazard, SOUFRIERE HILLS VOLCANO, MONTSERRAT, FRACTURE, SEISMOLOGY, VELOCITIES, ERUPTIONS, GRANITE, EVENTS, GROWTH, DAMAGE
UCL classification: UCL
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Earth Sciences
URI: https://discovery.ucl.ac.uk/id/eprint/10117717
Downloads since deposit
42Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item