Compilation of a high-quality catalogue for M3.0+ seismicity in northern Iran region for the period of 2005-2017
Abstract
The Iranian plateau is one of the seismically active areas of the world and frequently suffers destructive and catastrophic earthquakes. A precise and consistent local earthquake catalogue is a prerequisite not only for traditional seismic hazard assessment but also in the understanding of correlation of seismicity with the lithosphere structure and its tectonics. The two national observatories IRSC and BIN, complemented by few local observatories, operate seismic networks and each separately produces a seismic catalogue. Due to differences in the network geometry and in data processing, the two catalogues exhibit significant differences in the event location solutions and, surprisingly, in the number of events, also for strong earthquakes that occurred in recent years. High-quality and consistent seismic catalogues are best established by solving the coupled hypocentre-velocity problem, a fundamental task inherent to seismic tomography. In this work, we present the products of and the procedures for merging routine catalogues and for a consistent semi-automated re-picking of P-wave arrival times from local to regional scale. The final data set consists of more than 25 000 high-quality first P-wave arrivals from 1648 events used to derive a regional minimum 1-D model for northern Iran and four subregional 1-D models in four selected areas. We then used the regional minimum 1-D model with corresponding station delays for all stations operated in northern Iran to establish a combined high-quality local earthquake catalogue with uniformly consistent location and associated uncertainties. Thus the two main products of this study are the regional reference velocity model well suited for routine high-precision hypocentre location and the combined high-quality ReKiNIRAN-17 local earthquake catalogue for the period 2005-2017.
- Publication:
-
Geophysical Journal International
- Pub Date:
- October 2018
- DOI:
- 10.1093/gji/ggy271
- Bibcode:
- 2018GeoJI.215..118R
- Keywords:
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- Seismicity and tectonics;
- Seismic tomography;
- Earthquake hazard;
- Earthquake source observations