ORCID Profile
0000-0002-3826-0663
Current Organisation
Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences
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Publisher: Research Square Platform LLC
Date: 17-09-0006
DOI: 10.21203/RS.3.RS-2998116/V1
Abstract: A sequence of injection-induced earthquakes in western Canada demonstrates a resurgent response of a fault system to persistent, post-mainshock saltwater disposal. Compared with independent analysis, joint inference of InSAR and seismic waveform data significantly reduces uncertainty in source parameters, showing that the mainshock nucleated at 5-km depth, propagating up-dip towards the injection source, arresting at 1.9-km depth. Precise hypocenter relocations, combined with Bayesian inference, reveal that four subparallel faults were reactivated, likely part of a regional, basement-rooted graben system. The reactivated faults appear to be truncated by a conjugate fault that is misoriented for slip in the present-day stress regime. The nearest saltwater disposal well targets a permeable Devonian reef that is in direct contact with Precambrian basement, atop a ridge-like uplift. Our observations show that a fault system can be activated more than a decade after initiation of saltwater disposal, and continued disposal may lead to resurgence of seismicity.
Publisher: Seismological Society of America (SSA)
Date: 22-01-2020
DOI: 10.1785/0220190075
Abstract: The Bayesian earthquake analysis tool (BEAT) is an open-source Python software to conduct source-parameter estimation studies for crustal deformation events, such as earthquakes and magma intrusions, by employing a Bayesian framework with a flexible problem definition. The software features functionality to calculate Green’s functions for a homogeneous or a layered elastic half-space. Furthermore, algorithm(s) that explore the solution space may be selected from a suite of implemented s lers. If desired, BEAT’s modular architecture allows for easy implementation of additional features, for ex le, alternative s ling algorithms. We demonstrate the functionality and performance of the package using five earthquake source estimation ex les: a full moment-tensor estimation a double-couple moment-tensor estimation an estimation for a rectangular finite source a static finite-fault estimation with variable slip and a full kinematic finite-fault estimation with variable hypocenter location, rupture velocity, and rupture duration. This software integrates many aspects of source studies and provides an extensive framework for joint use of geodetic and seismic data for nonlinear source- and noise-covariance estimation within layered elastic half-spaces. Furthermore, the software also provides an open platform for further methodological development and for reproducible source studies in the geophysical community.
Publisher: Seismological Society of America (SSA)
Date: 12-09-2023
DOI: 10.1785/0220220001
Abstract: On 10 September, 2008, an Mw 5.7 earthquake occurred under the Central Valley of northern Chile near the town of Pica at a depth of ∼33 km within the continental crust of the South America plate. We find this earthquake to be a high stress-drop, reverse-oblique event that generated unusually high ground accelerations of up to 0.67g. Overall, its observed ground motion intensities are considerably larger than those predicted by ground motion models, particularly at short periods. The source properties inferred through waveform modeling indicate reverse-oblique fault motion on a ∼75 km2 plane dipping to the northeast, which is corroborated by the located aftershock distribution. Stress-drop values of the mainshock and larger aftershocks were estimated through S-wave spectrum modeling, with values up to ∼250 MPa for the mainshock. The event occurred in a cold section of the continental crust under the Central Valley, and its fault kinematics and orientation are consistent with the dominant style of faulting and stress field under the neighboring Coastal Cordillera. Although our recurrence analysis shows that crustal events in the region occur at a lower rate than interplate and inslab events, crustal events of similar or higher magnitude than the Pica earthquake have occurred, on average, approximately once every three years in northern Chile, which could pose an important hazard to nearby populations or critical infrastructure.
Location: Germany
Location: Saudi Arabia
No related grants have been discovered for Hannes Vasyura-Bathke.