FaultLab: Seismic Imaging
As one of the major strike-slip faults on the planet, the North-Anatolian Fault Zone is a fascinating structure to understand the structure of fault zones and the dynamics of the earthquake cycle. In May 2012 we installed a 70-element seismic network (Dense Array for North-Anatolia – DANA) as part of the FaultLab project. The main footprint of the array encompasses 35 by 70 km with a nominal interstation spacing of 7 km. This unusual array configuration will provide us with a very dense record of the seismic wavefield and has been optimized to image the detailed structure of the damage zone of the main strand of the fault.
We aim to image the fault zone structure using the novel technique of scattering tomography (Frederiksen and Revenaugh, 2004). The coda of teleseismic P-wave arrivals contains energy scattered by small-scale heterogeneities in the receiver-side lithosphere. This scattered energy can be used in a linear inversion scheme to extract small-scale P-wave, S-wave and density perturbations in the lithosphere beneath the stations and provides complimentary information to traditional travel time tomography.
The dense sampling of the seismic wavefield will allow the application of a multitude of seismic analysis methods. Planned analyses include: teleseismic and local body wave traveltime tomography, surface wave tomography, receiver function analysis, scattering migration, ambient noise analysis and analysis of guided fault waves.
References:
Frederiksen A., and J. Revenaugh, Lithospheric imaging via teleseismic scattering tomography, Geophys. J. Int., 159, 978-990, 2004.