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| Titel |
Effect of dehydration reactions on the temperature of faults during coseismic slip |
| VerfasserIn |
Nicolas Brantut, Raehee Han, Alexandre Schubnel, Shimamoto Toshihiko, Jérôme Corvisier |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250034000
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| Zusammenfassung |
| Recent experimental and theoretical studies have emphasized the possible importance of
mineral reactions during coseismic slip. Here we present a series of High Velocity
Friction experiments on gypsum solid blocks, performed at Hiroshima University. The
temperature close to the sliding surface and the relative humidity around the sample was
measured during slip tests at 1.3 m.s-1. The temperature on the sliding surface
is remarkably stable during the dehydration reaction of gypsum. Microstructural
investigations show that dehydration occurs at the very beginning of the test. Such
reactions might be recorded within the wall rock by the presence of anhydrite crystal
growth in the hottest parts of the sample. From a theoretical point of view at the
fault scale, it is possible to include mineral dehydrations within the framework
of Thermal Pressurization. Dehydrations are modeled as a source term for pore
pressure because of the total volume change, and a sink term for temperature because
they are endothermic. The solution is found numerically, taking into account fluid
and heat transport and using an Arrhenius law to calculate the rate constant with
temperature. The main effect of dehydration reactions is an increase of pore pressure and a
stabilization of the temperature during slip, as illustrated by the HVE on gypsum. |
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