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| Titel |
Velocity changes at Volcán de Colima: Seismic and Experimental observations |
| VerfasserIn |
Oliver Lamb, Yan Lavallée, Silvio De Angelis, Nick Varley, Gabriel Reyes-Davila, Raul Arambula-Mendoza, Adrian Hornby, Richard Wall, Jackie Kendrick |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250121687
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| Publikation (Nr.) |
 EGU/EGU2016-497.pdf |
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| Zusammenfassung |
| Immediately prior to dome-building eruptions, volcano-seismic swarms are a direct
consequence of strain localisation in the ascending magma. A deformation mechanism map
of magma subjected to strain localisation will help develop accurate numerical models,
which, coupled to an understanding of the mechanics driving monitored geophysical signals
prior to lava eruption, will enhance forecasts. Here we present how seismic data from Volcán
de Colima, Mexico, is combined with experimental work to give insights into fracturing in
and around magma.
Volcán de Colima is a dome-forming volcano that has been almost-continuously erupting
since November 1998. We use coda-wave interferometry to quantify small changes in
seismic velocity structure between pairs of similar earthquakes, employing waveforms
from clusters of repeating earthquakes. The changes in all pairs of events were
then used together to create a continuous function of velocity change at all stations
within 7 km of the volcano from October to December 1998. We complement our
seismic data with acoustic emission data from tensional experiments using samples
collected at Volcán de Colima. Decreases in velocity and frequency reflect changes
in the sample properties prior to failure. By comparing experimental and seismic
observations, we may place constraints on the conditions of the natural seismogenic
processes.
Using a combination of field and experimental data promises a greater understanding of
the processes affecting the rise of magma during an eruption. This will help with the
challenge of forecasting and hazard mitigation during dome-forming eruptions worldwide. |
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