Earthquakes and active faults in western and northern Pakistan and adjacent parts of Afghanistan are the result of the Indian plate moving northward at a rate of about 40 mm/yr (1.6 inches/yr) and colliding with the Eurasian plate. Along the northern edge of the Indian subcontinent, the Indian plate is subducting beneath the Eurasian plate, causing uplift that produces the highest mountain peaks in the world, including the Himalayan, the Karakoram, the Pamir and the Hindu Kush ranges. West and south of the Himalayan front, the relative motion between the two plates is oblique, which results in strike-slip, reverse-slip, and oblique-slip earthquakes. The pattern of elastic waves that were radiated by the October 28 and 29, 2008, earthquakes implies that each earthquake was the result of predominantly strike-slip faulting. Seismographically recorded waveforms imply that the shocks were caused by either left-lateral slip on a northeast-striking fault or right-lateral slip on a northwest-striking fault. The tectonic setting favours left-lateral slip on a northeast-trending fault as the likely fault plane.