Ambient noise seismic monitoring of the continuous deformation of the Earth

Abstract

The analogy between the Green function and the long-range correlation of the seismic ambient noise leads to new developments in imaging and monitoring. In the last years this approach allows for high-resolution surface wave tomography, and more recently its potential for body wave imaging was demonstrated. In the same time, the reconstruction of the scattered part of the Green function was analyzed and its possible use to detect slight variations in the medium was confirmed. Ambient noise monitoring allows for a continuous measure of seismic velocity changes related with the tectonic process affecting the lithosphere. I present some examples showing that a change at depth can be monitor with seismic noise records and that those changes are related to the deformation. We analyze in detail the transient deformation on a subduction zone and we discuss the relations between change of seismic velocity, slow slip events and tremors.