HR: 0800h
AN: G11A-1198    [Abstracts]
TI: Local Group Velocity of Ionospheric Waves Induced by Earthquakes
AU: * Crespon, F
EM: crespon@ipgp.jussieu.fr
AF: Institut de Physique du GLobe de Paris, 4 avenue de Neptune, St Maur des fosses, 94107 France
AU: Garcia, R
EM: garcia@ipgp.jussieu.fr
AF: Institut de Physique du GLobe de Paris, 4 avenue de Neptune, St Maur des fosses, 94107 France
AU: Occhipinti, G
EM: occhip@ipgp.jussieu.fr
AF: Institut de Physique du GLobe de Paris, 4 avenue de Neptune, St Maur des fosses, 94107 France
AU: Lognonne, P
EM: lognonne@ipgp.jussieu.fr
AF: Institut de Physique du GLobe de Paris, 4 avenue de Neptune, St Maur des fosses, 94107 France
AB: Past studies have shown that earthquakes are one of the geophysical events disturbing the ionosphere through the interaction between the atmospheric infrasound emitted by ground movements and the ionospheric plasma. The ionospheric electron density perturbations induced by earthquakes are regularly monitored by space-based instruments like dual frequency Global Positioning System receivers. This monitoring can reach high time and space resolution above dense networks of GPS receivers providing efficient ionospheric sensors. We present a data processing method extracting the local group velocity of ionospheric perturbations from GPS receiver Total Electron Content estimates. We illustrate this method on data obtained from dense GPS networks for several earthquakes in near field (r<300km from the source) and far field (r>1000 km). The local group velocity of the ionospheric perturbation is interpreted in terms of infrasonic waves in the atmosphere. Finally we discuss the usefulness of these data for retreiving seismological parameters related to surface wave propagation and to earthquake source mechanism.
DE: 2435 Ionospheric disturbances
SC: Geodesy [G]
MN: Fall Meeting 2005