The Western Makran Active Seismic Transects Preliminary Results

Abstract

The Makran subduction zone is a result of the northward subduction of the Arabian plate beneath the Eurasian plate. It is located in a complicated tectonic setting. From seismicity point of view, the east and west Makran have two different characteristics; the latest being considered as seismically more active. But in general, the seismicity in the region compared to other subduction zones in the world and at the same time with respect to its low surrounding. These three active seismic crustal scale refraction/wide angle reflection data together with large explosions, the necessary data has been acquired. In this paper using the newly acquired seismic data, a better estimation of the plate geometry of the western part of the Makran subduction zone (Iran), the crustal structure and hence the seismo-genic and tsunami-genic potential of this region were discussed. a relatively low seismicity, three earthquakes generating tsunamis in the Makran region have been reported [1, 2, 4]. Due to low seismicity access to seismic data for structural modeling and velocity analysis, we faced many challenges. In this respect in September 2017 three north-south oriented crustal-scale seismic refraction lines across onshore Markan have been acquired. Along each profile 315 autonomous seismic recorders were deployed and 9–10 artificial shots were fired. The distance between each shot point along each profile was approximately 20 km. This work was intiated by discussing the data acquisition. Then, the data quality was reviewed and the first result based on travel time picking and tomographic modeling was elaborated. It is important to mention that these types of data were achieved and gathered for the first time in the region.