The mechanism of microearthquakes related to a gas storage using differently constrained source models: a case study of the Háje location, Czech Republic

0463879 - GFÚ 2018 RIV CH eng J - Journal Article
Jechumtálová, Zuzana - Šílený, Jan - Málek, Jiří
The mechanism of microearthquakes related to a gas storage using differently constrained source models: a case study of the Háje location, Czech Republic.
Pure and Applied Geophysics. Roč. 174, č. 1 (2017), s. 177-195. ISSN 0033-4553. E-ISSN 1420-9136
R&D Projects: GA ČR GAP210/12/2235; GA ČR(CZ) GA16-03950S
Institutional support: RVO:67985530 ; RVO:67985891
Keywords : moment tensor * shear-tonsile crack * double couple
OECD category: Volcanology; Geology (USMH-B)
Impact factor: 1.652, year: 2017

The resolution of a source mechanism is investigated in terms of three differently constrained source models: the moment tensor, the shear-tensile crack source model, and the double couple source model. The moment tensor (MT) is an unconstrained description of a general dipole source. The shear-tensile crack (STC) represents a slip along a fault with an off-plane component and the double couple (DC) corresponds to a simple shear slip along a fault. The inversion of body wave amplitudes is applied on microseismic events located in the vicinity of underground gas storage Haje (Czech Republic) where volume changes in the source can be expected. The orientation of the simple shear fracture component is resolved almost always well, independently of the source model used. On the other hand, the non-shear components differ largely among the source models considered, from both the model definition and robustness of the inversion. A comparison of the inversion results for the three alternative source models permits an assessment of the reliability of the non-shear components retrieved. Application of the STC model to all events appears to be the most appropriate. The analysis confirms a shear slip for three events and a tensile fracturing for other three events.
Permanent Link: http://hdl.handle.net/11104/0263013