Iterative joint inversion for stress and fault orientations from focal mechanisms

0430240 - GFÚ 2015 RIV GB eng J - Journal Article
Vavryčuk, Václav
Iterative joint inversion for stress and fault orientations from focal mechanisms.
Geophysical Journal International. Roč. 199, č. 1 (2014), s. 69-77. ISSN 0956-540X. E-ISSN 1365-246X
R&D Projects: GA ČR(CZ) GAP210/12/1491
Institutional support: RVO:67985530
Keywords : earthquake source observations * seismicity and tectonics * theoretical seismology
Subject RIV: DC - Siesmology, Volcanology, Earth Structure
Impact factor: 2.560, year: 2014

Stress inversions from focal mechanisms require knowledge of which nodal plane is the fault. If such information is missing, and faults and auxiliary nodal planes are interchanged, the stress inversions can produce inaccurate results. It is shown that the linear inversion method developed by Michael is reasonably accurate when retrieving the principal stress directions even when the selection of fault planes in focal mechanisms is incorrect. However, the shape ratio is more sensitive to the proper choice of the fault and substituting the faults by auxiliary nodal planes introduces significant errors. This difficulty is removed by modifying Michael's method and inverting jointly for stress and for fault orientations. The fault orientations are determined by applying the fault instability constraint and the stress is calculated in iterations.
Permanent Link: http://hdl.handle.net/11104/0235134