February 21, 2011 Earthquake: Christchurch, Lyttelton, New Zealand

Felt Report

At least 181 people killed, 1,500 injured and about 100,000 buildings destroyed or damaged (VIII) in the Christchurch-Lyttleton area. Landslides and liquefaction occurred in the area. Felt in much of Canterbury and as far as Invercargill and Palmerston North.

Tectonic Summary

The February 21, 2011 South Island, New Zealand earthquake occurred as part of the aftershock sequence of the M 7.0 September 3, 2010 Darfield, NZ earthquake. The February 21st earthquake involved oblique-thrust faulting at the easternmost limit of previous aftershocks, and like the mainshock itself is broadly associated with regional plate boundary deformation as the Pacific and Australia plates interact in the central South Island, New Zealand. This latest shock is significantly closer to the main population center of Christchurch, NZ, than is the September 2010 mainshock, in the vicinity of several other moderate (M 4 to 5) sized aftershocks located east of the main rupture zone of the 2010 event. There is no specific structure directly linking this event to the main fault of the 2010 mainshock, although there have been numerous aftershocks along generally east-west linear trends extending east from the end of the previous rupture. The north or north-east trends to the possible fault planes and the oblique thrust faulting mechanism as seen in the focal mechanism solution may reflect an association with similarly-trending faults previously mapped in the Port Hills region, just to the south of Christchurch. Since the September 3, 2010 mainshock, there have been approximately 6 M>=5.0 aftershocks in the Christchurch region. The February 21st earthquake represents the largest aftershock to date, more that half a magnitude unit larger than the previous largest aftershock. (reference #1053)

CHRISTCHURCH, New Zealand -- A powerful earthquake struck one of New Zealand's biggest cities Tuesday at the height of a busy workday, toppling tall buildings and churches, crushing buses and killing at least 65 people in one of the country's worst natural disasters. (reference #9290)

At today's press conference Superintendent Dave Cliff said police expected the death toll to climb from the current number of 166 confirmed dead to 182. Previously they estimated the toll would be 180. He warned that it would be a slow process identifying the last victims as all the had to go on was the "fragments of human remains", he said. To date we have confirmed the identity of 140 of the victims and expect that number to rise in the coming days, however the point we're reaching now is that the identity of those last number of bodies is becoming increasingly difficult. (reference #9316)

181 killed, $15000 million damage. (reference #1250)

As at 9 February 2012, the official earthquake toll was 185 victims. (reference #12865)

$18000 million economic loss. (reference #13727)