Repeating earthquakes are sequences of microseismic events with highly similar seismograms and magnitudes suggesting quasi-periodic rupturing of the same asperity. They are observed on creeping fault segments and also in earthquake swarms. West Bohemia/ Vogtland swarms consist of many thousands of ML < 4 events occurring along a small area of fault zone with repeated activation of some patches during the swarms and weak background activity in the intermediate periods. Detecting and analyzing the repeating earthquakes represents a promising tool for identifying fault areas that are active permanently. This could point to the possible sources of fluids that are supposed to play significant role in swarm generation. Analyzing individual sequences could also reveal the possible velocity variations due to stress and pore pressure changes. In the proposed project it is planned to develop or implement efficient detection algorithm to identify repeating earthquakes in the seismic monitoring dataset. The resulting family of repeaters will be further processed to obtain their source parameters and/or possible seismic velocity variations with respect to the profile of the PhD candidate who is expected to employ his numerical and programing skills and seismological background.
Fischer T., Hainzl S., 2017. Effective Stress Drop of Earthquake Clusters, Bull. Seism. Soc. Am., 107, No. 5, pp. 2247–2257.
Fischer T., Matyska C., and Heinicke J., 2017. Earthquake-enhanced permeability - evidence from carbon dioxide release following the ML 3.5 earthquake in West Bohemia. Earth Planet. Sci. Lett., 460, 60–67.
Hainzl, S., Fischer, T., Čermáková, H., Bachura, M. and Vlček, J., 2016. Aftershocks triggered by fluid- intrusion: Evidence for the aftershock sequence occurred 2014 in West Bohemia/Vogtland, J.Geophys. Res. Solid Earth, 121.
Bachura M., Fischer T., 2016. Detailed velocity ratio mapping during the aftershock sequence as a tool to monitor the fluid activity within the fault plane. Earth Planet. Sci. Lett., 453, 215-222.
Vlček J., Fischer T. and Vilhelm J., 2016. Back-projection stacking of P- and S-waves to determine location and focal mechanism of microseismic events recorded by a surface array. Geophysical Prospecting 64, 1428-1440.
RINGEN – Research Infrastructure for Geothermal Energy, MŠMT LM2015084, 2016-2020
CzechGeo/EPOS– Distributed system of observatory and field geophysical field measurements in the Czech Republic, MŠMT LM2015079, 2016-2020
RINGEN – Research Infrastructure for Geothermal Energy, MŠMT LM2015084, 2016-2020
New project, after 2020