Seismic Hazards and risk assessment of Badakhshan region (northeast Afghanistan)

Abstract

The Badakhshan region in the northeast of Afghanistan has a complex geology that was created as a result of the collision of the Indian and Eurasian blocks. Using EMME seismographic catalogue data, with updates (years 2011-2021), from the website of Harvard University, International Seismic Research Centre (ISC) and USGS, a catalogue of earthquake epicentres. A device has been prepared. Then, according to the last earthquake of magnitude 7.2 in 2015, coefficients a and b have been calculated at the surface and depth. This value for b value is 1.0 in the northern half and a value is 7.9 in the southern half. The numerical increase of a and b in the central and southern half after the 2015 event has been quite evident. Earthquake prediction in the southern half of Badakhshan will increase in the future. According to the trend of earthquakes, the results indicate that contrary to the direction of the main fault in North Badakhshan (North-South), the highest frequency of earthquakes is 4≤ at a depth of 70-150 km, earthquakes are 5≤, and the depth of 150-300km from the earth and finally 6≤ at the depth of 300-700km in the east-west direction. This area is exactly where the Pamir Corridor plate subducts due to the pressure of the Indian plate in the west and southwest of Badakhshan. The tectonic situation of the region subducts to the south and southwest and causes compression and bending in the south of Badakhshan.