Variations of crustal elastic properties during the 2009 L'Aquila earthquake inferred from cross-correlations of ambient seismic noise.

Lucia Zaccarelli (1, 2) , N.M. Shapiro (1) , L. Faenza (3) , G. Soldati (3) , Alberto Michelini (4)

1 IPGP - Institut de Physique du Globe de Paris
2 INGV - Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Bologna
3 INGV - Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Roma
4 INGV - Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Catania

We retrieve seismic velocity variations within the Earth's crust in the region of L'Aquila (central Italy) by analyzing cross-correlations of more than two years of continuous seismic records. The studied period includes the April 6, 2009, Mw 6.1 L'Aquila earthquake. We observe a decrease of seismic velocities as a result of the earthquake's main shock. After performing the analysis in different frequency bands between 0.1 and 1 Hz, we conclude that the velocity variations are strongest at relatively high frequencies (0.5-1 Hz) suggesting that they are mostly related to the damage in the shallow soft layers resulting from the co-seismic shaking.

Domaines: Sciences de la Terre

Lucia Zaccarelli, N.M. Shapiro, L. Faenza, G. Soldati, Alberto Michelini. Variations of crustal elastic properties during the 2009 L'Aquila earthquake inferred from cross-correlations of ambient seismic noise.. Geophysical Research Letters, 2011, VOL. 38, pp.6 PP. ⟨10.1029/2011GL049750⟩. ⟨hal-00706545⟩