WELLINGTON, Feb 22, 2011 (AFP) - The 6.3 magnitude earthquake which rattled the New Zealand city of Christchurch on Tuesday was among the most serious to hit the earthquake-prone country since records began.
The quake struck at 12.51pm (2351 GMT) at a depth of four kilometres (2.5 miles) and was centred five kilometres northwest of Christchurch, according to the US Geological Survey. It was followed by several strong aftershocks measuring up to 5.6 in strength.
New Zealand sits on the so-called "Ring of Fire", the boundary of the Australian and Pacific tectonic plates, and experiences up to 15,000 tremors a year. It averages at least one a day of magnitude 4.0 or stronger.
This TV frame from NZ TV3 via Sky News shows the Christchurch Cathedral partially collapsing during a 6.3 earthquake which hit the city of Christchurch on February 22, 2011. AFP
Historic recorded earthquakes in the country are:
8.2 - January 23, 1855. Centred in the lower North Island and the most severe quake in New Zealand since European colonisation began in 1840. Thought to have killed seven to nine people.
7.8 - July 16, 2009, only 12 kilometres deep in the remote Fiordland region. No casualties reported.
7.8 - February 3, 1931. Centred in the Hawke's Bay. Claimed 256 lives in the most damaging of any recorded New Zealand quake.
7.8 - June 17, 1929. In the Buller region on the West Coast of the South island. Some 15 people killed.
7.8 - October 16, 1848. Marlborough region.
7.6 - March 5 1934. Pahiatua in the lower North Island.
7.2 - June 24, 1942. In Wairarapa, lower North Island.
7.1 - May 24, 1968. At Inangahua on West Coast of South Island. Killed three.
7.1 - September 1, 1888. North Canterbury.
7.0 - September 4, 2010. Christchurch. Widespread damage but no deaths.
6.3 - February 22, 2011. Christchurch. Multiple fatalities and extensive damage.