Seismic anisotropy and attenuation retrieved from waveform recordings of acoustic emissions and observations of natural and induced seismicity
Final Report Abstract
The project focussed on analyzing seismic waveform recordings of induced earthquakes in the largest producing geothermal field in the world, The Geysers in California/USA. We performed several studies of both broadband and short-period seismic waveform recordings with regard to analyze (1) their frequency content and subsequent role for determining the seismic moment tensor, (2) the interaction between induced seismicity and hydraulic boundary conditions such a flow rates, (3) the stress field within the reservoir and its spatial and temporal variations, and (4) anisotropy throughout the field. Two particular and entirely novel attempts/results were to combine collocated short-period and broadband seismic stations recording the same seismic events allowing for a direct comparison between either recordings, and the observation of a clear relation between the (higher) frequency content of the body waves and the non-double couple component (especially isotropic) of the respective moment tensor.
Publications
- Moment tensors of induced microearthquakes in The Geysers geothermal reservoir from broadband seismic recordings: Implications for faulting regime, stress tensor and fluid pressure, J. Geophys. Res., Solid Earth, 2018
Yu, C., Vavryčuk, V., Adamová, P., Bohnhoff, M.
(See online at https://doi.org/10.1029/2018JB016251) - Frequency‐dependent moment tensors of induced microearthquakes. Geophys. Res. Lett., 46, 2019
Yu, C., Vavryčuk, V., Adamová, P., Bohnhoff, M.
(See online at https://doi.org/10.1029/2019GL082634)
