the 1997 qayen earthquake was a large earthquake that struck in northern iran's khorasan province on may 10, 1997. it was also known as the quayen, ardekul or qaen earthquake. it was the largest in that area since 1990 and measured 7.3 on the moment magnitude scale. it was the third earthquake in 1997 that caused a lot of damage. it killed 1,567 people and injured over 2,300. it also left 50,000 homeless by damaging over 15,000 homes. there were 155 aftershocks that added to the damage, which was guessed to cost about $100 million.