TY  - JOUR
A1  - Grigoli, Francesco
A1  - Cesca, Simone
A1  - Rinaldi, Antonio Pio
A1  - Manconi, Andrea
A1  - Lopez-Comino, José Ángel
A1  - Clinton, John F.
A1  - Westaway, Rob
A1  - Cauzzi, Carlo
A1  - Dahm, Torsten
A1  - Wiemer, Stefan
T1  - The November 2017 M-w 5.5 Pohang earthquake
BT  - a possible case of induced seismicity in South Korea
JF  - Science
N2  - The moment magnitude (M-w) 5.5 earthquake that struck South Korea in November 2017 was one of the largest and most damaging events in that country over the past century. Its proximity to an enhanced geothermal system site, where high-pressure hydraulic injection had been performed during the previous 2 years, raises the possibility that this earthquake was anthropogenic. We have combined seismological and geodetic analyses to characterize the mainshock and its largest aftershocks, constrain the geometry of this seismic sequence, and shed light on its causal factors. According to our analysis, it seems plausible that the occurrence of this earthquake was influenced by the aforementioned industrial activities. Finally, we found that the earthquake transferred static stress to larger nearby faults, potentially increasing the seismic hazard in the area.
Y1  - 2018
U6  - https://doi.org/10.1126/science.aat2010
SN  - 0036-8075
SN  - 1095-9203
VL  - 360
IS  - 6392
SP  - 1003
EP  - 1006
PB  - American Assoc. for the Advancement of Science
CY  - Washington
ER  - 
TY  - GEN
A1  - Kriegerowski, Marius
A1  - Cesca, Simone
A1  - Ohrnberger, Matthias
A1  - Dahm, Torsten
A1  - Krüger, Frank
T1  - Event couple spectral ratio Q method for earthquake clusters
BT  - application to northwest Bohemia
T2  - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe
N2  - We develop an amplitude spectral ratio method for event couples from clustered earthquakes to estimate seismic wave attenuation (Q-1) in the source volume. The method allows to study attenuation within the source region of earthquake swarms or aftershocks at depth, independent of wave path and attenuation between source region and surface station. We exploit the high-frequency slope of phase spectra using multitaper spectral estimates. The method is tested using simulated full wave-field seismograms affected by recorded noise and finite source rupture. The synthetic tests verify the approach and show that solutions are independent of focal mechanisms but also show that seismic noise may broaden the scatter of results. We apply the event couple spectral ratio method to northwest Bohemia, Czech Republic, a region characterized by the persistent occurrence of earthquake swarms in a confined source region at mid-crustal depth. Our method indicates a strong anomaly of high attenuation in the source region of the swarm with an averaged attenuation factor of Qp < 100. The application to S phases fails due to scattered P-phase energy interfering with S phases. The Qp anomaly supports the common hypothesis of highly fractured and fluid saturated rocks in the source region of the swarms in northwest Bohemia. However, high temperatures in a small volume around the swarms cannot be excluded to explain our observations.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 683 
KW  - west bohemia
KW  - attenuation tomography
KW  - swarm earthquakes
KW  - focal zone
KW  - parameters
KW  - locations
KW  - fault
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-426029
IS  - 683
ER  -