Crust and upper-mantle imaging by using P and S receiver functions in different tectonic regimes

Abstract

P and S receiver functions (RF) are effective tools to solve crustal and upper-mantle velocity contrasts. In this respect, RFs are utilized to image three different tectonic regimes of Anatolia. Firstly, western segment of the North Anatolian Fault Zone (NAFZ) is inspected by data from a dense broadband network (Dense Array for North-Anatolia - DANA) of 71 seismic stations with a nominal station spacing of 7 km in the vicinity of the 1999 Izmit earthquake. High resolved 2-D cross-section images reveal previously unkown small-scale structures and fault geometries in the crust and upper-mantle. Secondly, N-S extension dominated Western Anatolia (WA) is observed by 47 permanent broad-band stations. Totally, 3563 high signals to noise ratio P wave RFs with cut-off frequency of ~1 Hz are obtained among 43146 teleseismic earthquakes. Crustal differences, sharp Moho changes and low velocity zones are defined by 2-D cross-sections in the region. Lastly, Isparta Angle (IA) is imaged by data from a temporary and permanent broad-band seismic network that is composed 42 seismic stations. 4501 P wave RFs are used to resolve upper crustal and Moho depths and 946 S wave RFs are operated to figure out lithosphericasthenospheric boundary (LAB). Migrated P wave RFs cross-sections present Moho anomalies and African slab in the crust of IA. On the other hand, migrated S wave RFs cross-sections show variation of LAB boundary between ~50 to ~90 km depth range.