Spatio-temporal variations of b-value in and around north Pakistan

Abstract

The seismotectonic structure of north Pakistan has been formed by ongoing collision between the Eurasian and Indian plates. North Pakistan and the adjoining areas experienced many large earthquakes in the past, which resulted in considerable damages and loss of life. A magnitude-homogenous earthquake catalogue for north Pakistan and its surrounding areas for the instrumental period from 1964 to 2007 is used for analysis. We presented seismicity picture of the Hindukush–Pamir–Karakoram (HPK), Kohistan Island Arc (KIA) and Hazara–Kashmir–Himalayas (HKH) using various histograms and time series plots of the dataset. The b-value for each accreted domain is derived separately and investigated through a process of mutual correlation. Our computed temporal variation of b-value in Hazara region shows a significant decrease prior to 2005 Kashmir earthquake.