Kwiatek, G., P. Martínez-Garzón, G. Dresen, M. Bohnhoff, H. Sone, and C. Hartline (2015). Effects of long-term fluid injection on induced seismicity parameters and maximum magnitude in northwestern part of The Geysers geothermal field, J. Geophys. Res. 120, DOI 10.1002/2015JB012362. [ Article Page ]
We published another paper on induced seismicity, this time related to the clustering properties of induced seismicity observed in a couple of hydrothermal reservoirs. Here is the reference:
Martínez-Garzón, P., I. Zaliapin, Y. Ben-Zion, G. Kwiatek, and M. Bohnhoff (2018). Comparative Study of Earthquake Clustering in Relation to Hydraulic Activities at Geothermal Fields in California. Journal of Geophysical Research: Solid Earth, 123. DOI: 10.1029/2017JB014972 [ Article Page ]
Finally we published a paper related to investigation of seismic moment tensors of microseismic events at The Geysers geothermal field.
Martínez-Garzón, P., Kwiatek, G., Bohnhoff, M., and G. Dresen (2017). Volumetric components in the earthquake source related to fluid injection and stress state. Geophys. Res. Lett. 44, DOI: 10.1002/2016GL071963. [ Article Page ]
We investigate source processes of fluid-induced seismicity from The Geysers geothermal
reservoir in California to determine their relation with hydraulic operations and improve the corresponding seismic hazard estimates. Analysis of 869 well-constrained full moment tensors (Mw 0.8–3.5) reveals significant non-double-couple components (>25%) for about 65% of the events. Volumetric deformation is governed by cumulative injection rates with larger non-double-couple components observed near the wells and during high injection periods. Source mechanisms are magnitude dependent and vary significantly between faulting regimes. Normal faulting events (Mw<2) reveal substantial volumetric components indicating dilatancy in contrast to strike-slip events that have a dominant double-couple source. Volumetric components indicating closure of cracks in the source region are mostly found for reverse faulting events with Mw>2.5. Our results imply that source processes and magnitudes of fluid-induced seismic events are strongly affected by the hydraulic operations, the reservoir stress state, and the faulting regime.
We published a new paper in Journal of Geophysical Research: Solid Earth that discusses the influence of long-term fluid injection on fault reactivation potential at The Geysers geothermal field, California.
Martínez-Garzón, P., Kwiatek, G., Bohnhoff, M., and G. Dresen (2016). Impact of fluid injection on fracture reactivation at The Geysers geothermal field. J. Geophys. Res. 121, DOI: 10.1002/2016JB013137. [ Article Page ]
Another paper! This time we discuss the influence of temporal changes in pore pressure on the results of stress tensor inversion from focal mechanisms, with the special focus on stress shape ratio coefficient. There is also a neat presentation of the effects using the data from The Geysers geothermal field. The paper has been published in Geophysical Research Letters. Have fun!
Martínez-Garzón, P., Vavryčuk, V., Kwiatek, G., and M. Bohnhoff. Sensitivity of stress inversion of focal mechanisms to pore pressure changes (2016). Geophys. Res. Lett., 43, 8441-8450, DOI: 10.1002/2016GL070145. [ Article Page ]