A magnitude 7.1 earthquake occurred at 4.35 am on September 4, 2010. The epicentre was 40 km west of Christchurch at a depth of 33 km. Two serious injuries were incurred, but there were no directly-related fatalities.
More than 4,400 aftershocks were felt over the subsequent five months.
At 12.51 pm on February 22, 2011 a magnitude 6.3 earthquake struck, its epicentre in Lyttelton, 10 km south of Christchurch. It was only 5 km deep.
The close proximity and shallow depth of this quake which occurred at lunch time on a busy Tuesday resulted in 182 fatalities, numerous injuries, and the devastation of thousands of aftershock-weakened structures in and around the city and its environs.