High Quality Content by WIKIPEDIA articles! The Qayen earthquake, also known as the Ardekul or Qaen earthquake, was a major earthquake that struck Northern Iran`s Khorasan Province on May 10, 1997. The largest in the area since 1990, it measured 7.3 on the moment magnitude scale and was centered approximately 270 kilometers (170 mi) south of Mashhad on the village of Ardekul. The third earthquake that year to cause severe damage, it devastated the Birjand–Qayen region, killing 1,567 and injuring over 2,300. The earthquake—which left 50,000 homeless and damaged or destroyed over 15,000 homes—was described as the deadliest of 1997 by the United States Geological Survey. Some 155 aftershocks caused further destruction and drove away survivors. The earthquake was later discovered to have been caused by a rupture along a fault that runs underneath the Iran–Afghanistan border.