The 19 January 2011 M (sub w) 7.2 Dalbandin earthquake, Balochistan

The 19 January 2011 M (sub w) 7.2 Dalbandin earthquake at 01:23 a.m. local time (18 January 2011, 20:23 UTC) occurred south of the Makran-Balochistan volcanic arc at a depth of nearly equal 70 km and was followed by two globally recorded aftershocks. It appears to have occurred on a normal fault within the subducting Arabian-Ormara plate, where it descends beneath a southern promontory of the Eurasian plate. An unusual feature of this earthquake was that it was felt from Tehran to Delhi, and from the northern Persian Gulf states to central Asia, a radial felt extent of up to 1400 km; however it caused few fatalities and relatively modest damage. From the European Macroseismic Scale (EMS-98) intensities at 242 locations that are based on media reports and a field visit to the epicenter, we compare the attenuation of intensity with distance from the Dalbandin earthquake with observations from other intermediate-focus earthquakes in the Indian subcontinent. We also briefly discuss other similar historical earthquakes in western Balochistan, as well as the potential for site response in the city of Karachi in lieu of the varied intensities experienced during earthquakes since the mid-twentieth century. Online Material: Tabulated summaries of macroseismic accounts from 242 locations in the Indian subcontinent, central Asia, and the Middle East, where the 19 January 2011 Dalbandin earthquake was felt.