Regional Phase Attenuation across the Turkish-Iranian Plateau

Abstract:

We have constructed and validated regional wave (Pg and Lg) attenuation models for the crust and upper mantle throughout the Iranian plateau and surrounding regions. This research has increased ray path coverage of critical areas and help to create robust regional phase amplitude and attenuation models. We have recently combined our Iranian data set with our existing Middle Eastern Lg waveform database including stations from the recent CDCAT seismic experiment in central Anatolia. Together, these two data sets give us reasonably good coverage of the northern Middle East using both a two-station and reverse-two-station (RTM) attenuation measurements. We have also processed Pg waveforms in order to obtain robust estimates of Qp in the crust within the Anatolian-Iranian plateau. In general we have found a good correlation between Lg and Pg Q values with the exception of northwestern Iran. We are using our models of Qp and Qs for the crust to better understand the origin of the crustal models and to help determine the origin of the seismic anomalies in the crust beneath the Turkish-Iranian Plateau. We will correlate our Q models with variations in seismic wave speed from ambient noise tomography and local body wave tomography to understand whether composition or temperature anomalies are generating the observed seismic anomalies.