TY - JOUR
T1 - Rupture processes of the 2013-2014 Minab earthquake sequence, Iran
AU - Kintner, Jonas A.
AU - Ammon, Charles J.
AU - Michael Cleveland, K.
AU - Herman, Matthew
N1 - Funding Information:
This work was supported by the Air Force Research Laboratory under the Award FA9453-15-C-0064 and through partial support from the Defense Threat Reduction Agency under Award HDTRA1-11-1-0027.We thank the editor and two anonymous reviewers for comments that helped us improve this manuscript.We acknowledge the staff, support and data provided to the IRIS/USGS GSN, the Global Centroid-Moment-Tensor catalogue (Dziewonski et al. 1981; Ekström et al. 2012), International Seismological Centre (ISC), University of Tehran (TEH) and the United State Geologic Survey (USGS) Earthquake Hazards Program. The facilities of the IRIS Data Management System, and specifically the IRIS Data Management Center, were used for access to waveform and metadata required in this study. The IRIS DMS is funded through the National Science Foundation and specifically the GEO Directorate through the Instrumentation and Facilities Program of the National Science Foundation under Cooperative Agreement EAR-1063471. Thanks also to the developers of SAC (Goldstein et al. 2003), GMT (Wessel & Smith 1998), Coulomb (Toda et al. 2011), Python Software Foundation (www.python.org) and Obspy (Beyreuther et al. 2010; Megies et al. 2011; Krischer et al. 2015).
Publisher Copyright:
© The Author(s) 2018.
PY - 2018/6/1
Y1 - 2018/6/1
N2 - We constrain epicentroid locations, magnitudes and depths of moderate-magnitude earthquakes in the 2013-2014 Minab sequence using surface-wave cross-correlations, surfacewave spectra and teleseismic body-wave modelling. We estimate precise relative locations of 54 Mw ≥ 3.8 earthquakes using 48 409 teleseismic, intermediate-period Rayleigh and Lovewave cross-correlation measurements. To reduce significant regional biases in our relative locations, we shift the relative locations to align the Mw 6.2 main-shock centroid to a location derived from an independent InSAR fault model. Our relocations suggest that the events lie along a roughly east-west trend that is consistent with the faulting geometry in the GCMT catalogue. The results support previous studies that suggest the sequence consists of leftlateral strain release, but better defines the main-shock fault length and shows that most of the Mw ≥ 5.0 aftershocks occurred on one or two similarly oriented structures. We also show that aftershock activity migrated westwards along strike, away from the main shock, suggesting that Coulomb stress transfer played a role in the fault failure. We estimate the magnitudes of the relocated events using surface-wave cross-correlation amplitudes and find good agreement with the GCMT moment magnitudes for the larger events and underestimation of small-event size by catalogue MS. In addition to clarifying details of the Minab sequence, the results demonstrate that even in tectonically complex regions, relative relocation using teleseismic surface waves greatly improves the precision of relative earthquake epicentroid locations and can facilitate detailed tectonic analyses of remote earthquake sequences.
AB - We constrain epicentroid locations, magnitudes and depths of moderate-magnitude earthquakes in the 2013-2014 Minab sequence using surface-wave cross-correlations, surfacewave spectra and teleseismic body-wave modelling. We estimate precise relative locations of 54 Mw ≥ 3.8 earthquakes using 48 409 teleseismic, intermediate-period Rayleigh and Lovewave cross-correlation measurements. To reduce significant regional biases in our relative locations, we shift the relative locations to align the Mw 6.2 main-shock centroid to a location derived from an independent InSAR fault model. Our relocations suggest that the events lie along a roughly east-west trend that is consistent with the faulting geometry in the GCMT catalogue. The results support previous studies that suggest the sequence consists of leftlateral strain release, but better defines the main-shock fault length and shows that most of the Mw ≥ 5.0 aftershocks occurred on one or two similarly oriented structures. We also show that aftershock activity migrated westwards along strike, away from the main shock, suggesting that Coulomb stress transfer played a role in the fault failure. We estimate the magnitudes of the relocated events using surface-wave cross-correlation amplitudes and find good agreement with the GCMT moment magnitudes for the larger events and underestimation of small-event size by catalogue MS. In addition to clarifying details of the Minab sequence, the results demonstrate that even in tectonically complex regions, relative relocation using teleseismic surface waves greatly improves the precision of relative earthquake epicentroid locations and can facilitate detailed tectonic analyses of remote earthquake sequences.
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U2 - 10.1093/gji/ggy085
DO - 10.1093/gji/ggy085
M3 - Article
AN - SCOPUS:85052629640
VL - 213
SP - 1898
EP - 1911
JO - Geophysical Journal International
JF - Geophysical Journal International
SN - 0956-540X
IS - 3
ER -