Designing and testing a network of passive seismic surveying and monitoring in Dehdasht (South Western Iran)

Abstract

From August 2016 to July 2017, a passive seismic survey was conducted in South Western Iran as a part of a pilot project aimed to improve the imaging in geologically complex areas. Passive seismic methods have shown to be a useful tool to infer the physical properties of the underground geological structures where traditional hydrocarbon exploration methods are challenging. For this purpose, a dense passive seismic network consisting of 119 three‐component borehole seismic stations was deployed over an area of 400 km² around the city of Dehdasht. This paper focuses on the details of the network design, which was devoted to high‐resolution seismological applications, including local earthquake tomography and seismic attenuation imaging. In this regard, we describe the instrument types and the station installation procedures used to obtain high‐quality data that were used to retrieve three‐dimensional models of P‐ and S‐wave velocity and P‐wave attenuation in the area using tomographic inversion techniques. We also assess the network performance in terms of the seismic ambient noise levels recorded at each station site, and we revise the horizontal orientation of the sensors using surface waves from teleseismic earthquakes.