JOINT ANALYSIS OF THE ALOS-2 AND SENTINEL-1A DATA ON THE 2017 SEFID SANG EARTHQUAKE, NORTHEASTERN IRAN

The Iranian plateau is deformed between the converging Arabian and Eurasian plates. Their convergence is principally taken up by the active Makran subduction zone to the South, in addition to shortening and strike-slip faulting accommodated by crustal structures, which are non-uniformly distributed in several continental deformation domainssuch as the Zagros, Alborz and Kopeh Dagh mountain ranges. Indeed, despite all the efforts made by previous workers to shed light on active tectonics in northeast Iran, this region still suffers from a lack of detailed structural and kinematics data and should be considered as a concealed segment in the geodynamic puzzle of the Arabia-Eurasia collision. This matter is made worse by the facts that northeast Iran is the second populated region and one of the most seismically active deformation domains in the country that has experienced at least nine large earthquakes (M ≥ 7) during the last six centuries. On 5 April 2017, an Mw 6.1 earthquake occurred in the northeastern region of Iran, about 90 km southeast of the city of Mashhad, the second most populous city in Iran with a population of over 3 million people. The epicenter (35.776 N, 60.436 E, USGS) was at a remote mountainous area, about 30 km northeast of the Sefid Sang district where approximately 5000 people live, and the depth was about 13 km. This earthquake raised an opportunity to study the deformation pattern in the SE of the Kopeh Dagh Mountains. Space geodetic observations of ground deformation provide important data to investigate the seismogenic fault and the subsurface deformation mechanics. Here we used ALOS-2 and Sentinel-1A Synthetic Aperture Radar data (Table 1) to produce SARinterferograms using the GMTSAR software (Sandwell et al., 2016) to investigate coseismic and postseismic deformation associated with the 2017 Sefid Sang earthquake.

کلیدواژه ها:

Sefid Sang earthquake ، InSAR ، ALOS-2 ، Sentinel-1A ، Coseismic deformation