Elastic Versus Non-Elastic Co-Seismic Strain Response at the Trizonia Borehole Sacks Evertson Dilatometer in the Rift of Corinth, Greece, for a Local, Moderate Earthquake.
Abstract
The western part of the rift of Corinth, in Greece, is the site of continuous geophysical monitoring of its seismic and aseismic activity, in the frame of the Corinth Rift Laboratory project (CRL). The objectives of CRL is to contribute to a better understanding of the relationship between faults, fluids, and earthquakes. Among the various sensor arrays in operation (seismometers, accelerometers, strainmeters, tiltmeters, pore pressure in deep boreholes,.) , a Sacks-Evertson borehole dilatometer has been installed in the Trizonia island, 10 km above the roots of the major, north-dipping active normal faults. We present here the analysis of the dilatometer record of a local magnitude Ml=4.6 earthquake, which produced a clear coseismic static strain step. The simple modeling of the coseismic static deformation suggests a dominant non-linear response caused by the strong S-wave shaking. However, it is still possible to recover information on the source through the analysis and modeling of the intermediate and near-source terms recorded on the dilatometer before the S arrivals. The results are compared to the records of several sensors installed at less than 1 km away (an STS2 seismometer, two long base hydrostatic tiltmeters, and several short period tiltmeters).
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2004
- Bibcode:
- 2004AGUFM.G21A0117F
- Keywords:
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- 7223 Seismic hazard assessment and prediction;
- 7230 Seismicity and seismotectonics;
- 7294 Instruments and techniques;
- 1734 Seismology;
- 1242 Seismic deformations (7205)