Stress drop variations of induced earthquakes at the Basel geothermal site
2011; American Geophysical Union; Volume: 38; Issue: 9 Linguagem: Inglês
10.1029/2011gl047498
ISSN1944-8007
AutoresBettina Goertz-Allmann, A. Goertz, Stefan Wiemer,
Tópico(s)High-pressure geophysics and materials
ResumoWe determine stress drops from P‐wave spectra of about 1000 earthquakes induced by hydraulic stimulation in crystalline rock for a deep heat mining project in Basel, Switzerland. We observe an increase in stress drop by about a factor of five with radial distance from 10 m to 300 m, which suggests that stress drop correlates with pore pressure perturbations due to the injection. We test this hypothesis by calculating the injection‐related pore pressure perturbation based on a simple linear pore pressure diffusion model and find a good correlation of the expected pore pressure perturbation with the estimated stress drops.
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