Injection 2003 in HDR site Soultz-sous-Forets: microearthquake mechanisms and stress pattern

0369991 - GFÚ 2012 RIV NL eng C - Conference Paper (international conference)
Jechumtálová, Zuzana - Šílený, Jan - Horálek, Josef - Dorbath, L.
Injection 2003 in HDR site Soultz-sous-Forets: microearthquake mechanisms and stress pattern.
Third passive seismic workshop Actively Passive! Workshop proceedings. Houten: EAGE, 2011, s. 1-5. ISBN 978-90-73834-05-7.
[Passive seismic workshop Actively Passive! /3./. Athens (GR), 27.03.2011-30.03.2011]
R&D Projects: GA ČR GAP210/10/1728; GA AV ČR IAA300120911
Institutional research plan: CEZ:AV0Z30120515
Keywords : moment tensor * tectonic stress evaluation * Angelier method * temporal and space variations
Subject RIV: DC - Siesmology, Volcanology, Earth Structure

Stress evaluation is an immediate benefit of determination of fault-plane solution of events that occur on pre-existing faults within a zone of interest. We have retrieved the moment tensors of 45 microearthquakes with magnitudes between M=1.4 and 2.9 which occurred during the 2003 massive fluid injection in the borehole of the Soultz HDR-site. Surprisingly, the mechanisms were predominantly pure shear slips, i.e. with source mechanisms typical for tectonic earthquakes. To estimate the stress state within the zone of the hypocentra, we applied the approach of Angelier (2002), minimizing the slip shear stress component, advantageously avoiding a prior discrimination between fault and auxiliary plane.
Permanent Link: http://hdl.handle.net/11104/0203919