The unusual Bárðarbunga volcano earthquakes observed using high-rate GPS data.
Abstract
Volcanic earthquakes are controled by a wide range of physical parameters. Their relative importance, and how they are connected, can be difficult to discern, due to limited observations. For instance, volcanic seismic sources represented by the moment tensor, commonly have a large non-double couple component, which implies that the source can not be described as a slip on a planar fault. However, there are many volcanic phenomena that could explain a non-double couple component, such as intrusive processes such as dikes or sills (Kanamori et al 1993, Riel et al 2014) as well as geometric effects due slip on a circular fault (Nettles & Ekström, 1998). Therefore, the challange is not only finding a moment tensor that can predict the observations, but also interpreting the moment tensor in terms of an actual physical process. The 2014-2015 eruption of Holuhraun in NE Iceland, was accompanied by a subsidence of the 7x11 km circular caldera and large anomalous earthquakes (around seventy earthquakes between 5.0In this work, we look for a model of several point sources, varying parameters such as their location, timing, duration and mechanism, that best fits the available data.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.V33E3174R
- Keywords:
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- 1211 Non-tectonic deformation;
- GEODESY AND GRAVITYDE: 7280 Volcano seismology;
- SEISMOLOGYDE: 8145 Physics of magma and magma bodies;
- TECTONOPHYSICSDE: 8439 Physics and chemistry of magma bodies;
- VOLCANOLOGY