3-D velocity structure of Damavand volcano, Iran, from local earthquake tomography

Abstract

Damavand volcano is a large intraplate Quaternary composite cone overlying the active fold and thrust belt of the Central Alborz Mountains in northern Iran. In this study, we present the first 3-D P-wave velocity model of the upper crust for the Central Alborz region using local earthquake data provided by the Iranian Seismic Telemetry Network. The final P-wave velocity model reveals several high and low velocity anomalies in the upper 30 km of the crust. A low velocity zone parallel to the main faulting system is imaged at a depth of 15 km. A relatively high velocity body to the north of the Damavand summit down to a depth of 20 km is resolved, which may represent the elderly crystallized magma chamber. Right below the Damavand cone, a low velocity area to the depth of 7 km can be interpreted as a shallow magma chamber.