TY  - JOUR
A1  - Eulenfeld, Tom
A1  - Dahm, Torsten
A1  - Heimann, Sebastian
A1  - Wegler, Ulrich
T1  - Fast and robust earthquake source spectra and moment magnitudes from envelope inversion
JF  - The bulletin of the Seismological Society of America : BSSA
N2  - With the present study, we introduce a fast and robust method to calculate the source displacement spectra of small earthquakes on a local to regional scale. The work is based on the publicly available Qopen method of full envelope inversion, which is further tuned for the given purpose. Important source parameters-seismic moment, moment magnitude, corner frequency, and high-frequency fall off-are determined from the source spectra by fitting a simple earthquake source model. The method is demonstrated by means of a data set comprising the 2018 West Bohemia earthquake swarm. We report moment magnitudes, corner frequencies, and centroid moment tensors inverted from short-period body waves with the Grond package for all earthquakes with a local magnitude larger than 1.8. Moment magnitudes calculated by envelope inversion show a very good agreement to moment magnitudes resulting from the probabilisitc moment tensor inversion. Furthermore, source displacement spectra from envelope inversion show a good agreement with spectra obtained by multiple taper analysis of the direct onsets of body waves but are not affected by the large scatter of the second. The seismic moments obtained with the envelope inversion scale with corner frequencies according to M-0 proportional to f(c)(-4.7). Earthquakes of the present data set result in a smaller stress drop for smaller magnitudes. Self-similarity of earthquake rupture is not observed. In addition, we report frequency-dependent site amplification at the used stations.
Y1  - 2021
U6  - https://doi.org/10.1785/0120210200
SN  - 0037-1106
SN  - 1943-3573
VL  - 112
IS  - 2
SP  - 878
EP  - 893
PB  - Seismological Society of America
CY  - El Cerito, Calif.
ER  - 
TY  - GEN
A1  - Dahm, Torsten
A1  - Becker, Dirk
A1  - Bischoff, Monika
A1  - Cesca, Simone
A1  - Dost, B.
A1  - Fritschen, R.
A1  - Hainzl, Sebastian
A1  - Klose, C. D.
A1  - Kuhn, D.
A1  - Lasocki, S.
A1  - Meier, Thomas
A1  - Ohrnberger, Matthias
A1  - Rivalta, Eleonora
A1  - Wegler, Ulrich
A1  - Husen, Stephan
T1  - Recommendation for the discrimination of human-related and natural seismicity
T2  - Journal of seismology
N2  - Various techniques are utilized by the seismological community, extractive industries, energy and geoengineering companies to identify earthquake nucleation processes in close proximity to engineering operation points. These operations may comprise fluid extraction or injections, artificial water reservoir impoundments, open pit and deep mining, deep geothermal power generations or carbon sequestration. In this letter to the editor, we outline several lines of investigation that we suggest to follow to address the discrimination problem between natural seismicity and seismic events induced or triggered by geoengineering activities. These suggestions have been developed by a group of experts during several meetings and workshops, and we feel that their publication as a summary report is helpful for the geoscientific community. Specific investigation procedures and discrimination approaches, on which our recommendations are based, are also published in this Special Issue (SI) of Journal of Seismology.
KW  - Triggered seismicity
KW  - Induced seismicity
Y1  - 2013
U6  - https://doi.org/10.1007/s10950-012-9295-6
SN  - 1383-4649
VL  - 17
IS  - 1
SP  - 197
EP  - 202
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - THES
A1  - Wegler, Ulrich
T1  - Deterministische und statistische Untergrundmodelle des Vulkans Merapi (Java, Indonesien) : eine Analyse künstlich erzeugter seismischer Signale
Y1  - 1999
CY  - Potsdam
ER  -