Source mechanisms of micro-earthquakes induced in a fluid injection experiment at the HDR site Soultz-sous-Forêts (Alsace) in 2003 and their temporal and spatial variations

0348407 - GFÚ 2011 RIV GB eng J - Journal Article
Horálek, Josef - Jechumtálová, Zuzana - Dorbath, L. - Šílený, Jan
Source mechanisms of micro-earthquakes induced in a fluid injection experiment at the HDR site Soultz-sous-Forêts (Alsace) in 2003 and their temporal and spatial variations.
Geophysical Journal International. Roč. 181, č. 3 (2010), s. 1547-1565. ISSN 0956-540X. E-ISSN 1365-246X
R&D Projects: GA AV ČR IAA300120911; GA ČR GA205/09/0724
Grant - others:EU(XE) MTKI-CT-2004-517242
Institutional research plan: CEZ:AV0Z30120515
Keywords : downhole methods * hydrogeophysics * controlled source seismology * earthquake source observations * fracture and flow
Subject RIV: DC - Siesmology, Volcanology, Earth Structure
Impact factor: 2.411, year: 2010

We have inverted the peak amplitudes of direct P waves of 45 micro-earthquakes with magnitudes between M = 1.4 and 2.9, which occurred during and after the 2003 massive fluid injection in the GPK3 borehole of the Soultz-sous-Forets Hot Dry Rock facility. These events were recorded by a surface seismic network of 15 stations operated by the Ecole et Observatoire des Sciences de la Terre, University of Strasbourg. The unconstrained moment tensor (MT) expression of the mechanism was applied, allowing the description of a general system of dipoles, that is, both double-couple (DC) and non-DC sources, as tensile fractures. The mechanisms of all but one event are dominantly DCs with a few per cent additional components at the most.
Permanent Link: http://hdl.handle.net/11104/0188954