Use of 3-D Velocity Models and Ray Tracing in the Double Difference Earthquake Location Algorithms: Application to a Data set from the Mygdonia Basin (Northern Greece)
Abstract
In the past years there has been a growing demand for precise earthquake locations for seismicity, tectonics and seismic hazard studies. Recently this has become possible because of the development of sophisticated location algorithms, as well as hardware resources. This is expected to lead to a better insight of seismicity in the near future. A well-known technique, which has been implemented as a computer program and has been widely used for relocating earthquake data sets, is the double difference algorithm. In its original implementation it makes use of a one-dimensional ray tracing routine to calculate seismic wave travel times and partial temporal derivatives of source parameters. We have modified the implementation of the algorithm by incorporating a three-dimensional velocity model and ray tracing in order to locate a set of earthquakes in the area of the Mygdonia Basin (Northern Greece). This area is covered by a permanent regional network and occasionally by temporary local networks. The velocity structure is very well known, as the Mygdonia Basin has been used as an international test site for seismological studies since 1993, which makes it an appropriate location for evaluating earthquake location algorithms, with the quality of the results depending only on the quality of the data and the algorithm itself. The new earthquake locations reveal details of the area's structure, which are blurred, if not misleading, when resolved by standard (routine) location algorithms.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2003
- Bibcode:
- 2003AGUFM.S22F..06G
- Keywords:
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- 7200 SEISMOLOGY