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.

HR: 0800h
AN: G21A-0117 [Abstracts]
TI: 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.
AU: * frederick, b
EM: boudin@ipgp.jussieu.fr
AF: Departement de Sismologie, Institut de Physique du Globe de Paris, 4 Place Jussieu tour24 4eme, Paris, 75 75252 France, Metropolitan
AU: Pascal, B
EM: bernard@ipgp.jussieu.fr
AF: Departement de Sismologie, Institut de Physique du Globe de Paris, 4 Place Jussieu tour24 4eme, Paris, 75 75252 France, Metropolitan
AU: Marie-Paule, B
AF: Departement de Sismologie, Institut de Physique du Globe de Paris, 4 Place Jussieu tour24 4eme, Paris, 75 75252 France, Metropolitan
AU: Selwyn, S
EM: sacks@dtm.ciw.edu
AF: Carnegie Institution of Washington, 5251 Broad Branch Road, Washington, DC 10682 United States
AU: Alan, L
EM: linde@dtm.ciw.edu
AF: Carnegie Institution of Washington, 5251 Broad Branch Road, Washington, DC 10682 United States
AB: 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).
DE: 7223 Seismic hazard assessment and prediction
DE: 7230 Seismicity and seismotectonics
DE: 7294 Instruments and techniques
DE: 1734 Seismology
DE: 1242 Seismic deformations (7205)
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting