December 2011 Christchurch earthquakes

A magnitude 7.1 M_w earthquake, known as the Darfield earthquake, occurred on 4 September 2010, and had, at the time, the biggest ground shaking ever to be recorded in New Zealand, at 1.26 g (1.26 times the acceleration of gravity).{{cite web |year=2011 |title=2010 Darfield (Canterbury) Earthquake |url=http://www.gns.cri.nz/Home/News-and-Events/Media-Releases/Most-damaging-quake-since-1931/Canterbury-quake/Darfield-Earthquake |url-status=dead |archive-url=https://web.archive.org/web/20120728071017/http://www.gns.cri.nz/Home/News-and-Events/Media-Releases/Most-damaging-quake-since-1931/Canterbury-quake/Darfield-Earthquake |archive-date=28 July 2012 |access-date=27 August 2011 |publisher=GNS Science}}{{Cite journal |last1=Segou |first1=Margaret |last2=Kalkan |first2=Erol |date=2011 |title=Ground Motion Attenuation during M 7.1 Darfield and M 6.2 Christchurch, New Zealand, Earthquakes and Performance of Global Predictive Models |url=https://quakelogic.net/Pubs/74.pdf |journal=Seismological Research Letters |volume=82 |issue=6 |pages=866–874 |doi=10.1785/gssrl.82.6.866|bibcode=2011SeiRL..82..866S }} The Darfield quake occurred along the Greendale Fault, and had thousands of shallow aftershocks over the coming months. Most occurred along the fault's surface trace, but there was also a zone of aftershocks extending northwards from the middle of the fault trace, as well as beyond the western and eastern (towards Christchurch) sides.{{Cite web |last=Bannister |first=Stephen |date=March 2011 |title=Relocation Analysis of the Christchurch City "Boxing Day" Earthquakes GNS Science Consultancy Report 2011/36 |url=https://www.eqc.govt.nz/assets/Publications-Resources/216-Relocation-Analysis-of-the-Christchurch-City-Boxing-Day-Earthquakes-compressed.pdf |url-status=live |archive-url=https://web.archive.org/web/20240905071540/https://www.eqc.govt.nz/assets/Publications-Resources/216-Relocation-Analysis-of-the-Christchurch-City-Boxing-Day-Earthquakes-compressed.pdf |archive-date=5 September 2024 |access-date=15 August 2024 |website=Earthquake Commission}}{{Rp|page=3}} Most aftershocks were under magnitude 3 and did not cause significant damage,{{Cite web |title=2010 Canterbury (Darfield) earthquake |url=https://nzhistory.govt.nz/culture/canterbury-earthquake-september-2010 |access-date=1 March 2025 |website=New Zealand History |publisher=Ministry for Culture and Heritage}} however a few did, including the {{M|W|4.7}} 2010 Boxing Day earthquake quake and the {{M|w|6.2}} 22 February 2011 earthquake. The February earthquake was the most destructive of them all, causing 185 deaths{{Cite news |title=The 2011 Christchurch earthquake |url=https://teara.govt.nz/en/historic-earthquakes/page-13 |url-status=live |archive-url=https://web.archive.org/web/20231202120953/https://teara.govt.nz/en/historic-earthquakes/page-13 |archive-date=2 December 2023 |access-date=18 August 2024 |work=Te Ara: The Encyclopedia of New Zealand}} and tens of billion dollars in damage.{{Cite web |title=Canterbury Earthquakes |url=https://www.icnz.org.nz/industry/canterbury-earthquakes/ |access-date=27 February 2025 |website=Insurance Council of New Zealand}} A {{M|W|6.0}} earthquake in June 2011 followed and caused further damage.{{Cite web |title=Magnitude 6.0, Mon Jun 13 2011 2:20 PM |url=https://www.geonet.org.nz/earthquake/3528839 |access-date=3 May 2025 |website=GeoNet}}

The earthuakes occurred on 23 December, offshore, east of Christchurch, on faults under Pegasus Bay.{{Cite news |date=24 December 2011 |title=Offshore faults to blame for Christchurch shakes |url=https://www.stuff.co.nz/national/christchurch-earthquake/6186336/Offshore-faults-to-blame-for-Christchurch-shakes |access-date=30 November 2024 |work=Stuff}}

• Magnitude 5.8 at 1.58{{Nbsp}}pm, depth of {{Convert|10|km}}.{{Cite web |title=Magnitude 5.8, Fri Dec 23 2011 1:58 PM |url=https://www.geonet.org.nz/earthquake/3631359 |access-date=30 November 2024 |website=GeoNet}}

• Magnitude 5.0 at 2.00{{Nbsp}}pm, depth of {{Convert|8|km}}.{{Cite web |title=Magnitude 5.0, Fri Dec 23 2011 2:00 PM |url=https://www.geonet.org.nz/earthquake/3713255 |access-date=30 November 2024 |website=GeoNet}}
• Magnitude 5.4 at 2.06{{Nbsp}}pm, depth of {{Convert|7|km}}.{{Cite web |title=Magnitude 5.4, Fri Dec 23 2011 2:06 PM |url=https://www.geonet.org.nz/earthquake/3631363 |access-date=30 November 2024 |website=GeoNet}}
• Magnitude 5.9 at 3.18{{Nbsp}}pm, depth of {{Convert|7|km}}.{{Cite web |title=Magnitude 5.9, Fri Dec 23 2011 3:18 PM |url=https://www.geonet.org.nz/earthquake/3631380 |access-date=30 November 2024 |website=GeoNet}}

The earthquakes caused sewage outflows, including into the Avon River / Ōtākaro,{{Cite news |date=24 December 2011 |title=Swarm of quakes hits Christchurch |url=https://www.stuff.co.nz/national/6184519/Swarm-of-quakes-hits-Christchurch |access-date=3 May 2025 |work=Stuff}} which led to the encouragement of residents to keep away from the Avon Heathcote Estuary, city beaches and rivers.{{Cite news |date=26 December 2011 |title=Damage from quakes psychological - PM |url=https://www.stuff.co.nz/national/6186421/Cantabrians-pitch-in-for-quake-cleanup |access-date=30 November 2024 |work=Stuff}} The earthquakes also caused liquefaction, with the eastern suburbs being most affected.{{Cite news |date=24 December 2011 |title=Dual quakes rock Christchurch |url=https://www.abc.net.au/news/2011-12-23/christchurch-hit-with-another-earthquake/3745516 |access-date=1 May 2025 |work=ABC News}} Liquefaction and flooding was worst in Avondale, Bexley, Burwood, New Brighton and Parklands. Parklands also lost sewerage and water supply.{{Cite news |date=25 December 2011 |title=Essential repairs done by Christmas Day - council |url=https://www.rnz.co.nz/news/canterbury-earthquake/94623/essential-repairs-done-by-christmas-day-council |access-date=30 November 2024 |work=RNZ}} The liquefaction resulted in the closure of roads in the eastern suburbs and ones close to the central city.

The earthquake at 1.58{{Nbsp}}pm caused 26,000 properties to lose electricity. Power was restored to almost all them by the next day. The telecommunications network became strained and residents were encouraged to communicate using text message instead of calling.{{Cite news |date=23 December 2011 |title=Tremors will last for some time, GNS says |url=https://www.stuff.co.nz/national/6185025/Tremors-will-last-for-some-time-GNS-says |access-date=30 November 2024 |work=Stuff}} People travelling home caused the roads to become gridlocked. A magnitude 4.3 earthquake the next day at 1.21{{Nbsp}}am broke a water pipe, which had to be turned off in order to be repaired. This resulted in homes in Redcliffs and Sumner losing mains water supply. It was restored by the afternoon. As a precautionary measure, Christchurch Hospital and Princess Margaret Hospital used boiled water. Burwood Hospital had to run on backup power, and temporarily move its birthing unit.{{Cite news |date=24 December 2011 |title=St John kept busy with falls and cardiac cases |url=https://www.stuff.co.nz/the-press/news/6186273/St-John-kept-busy-with-falls-and-cardiac-cases |access-date=30 November 2024 |work=The Press}}

Cliffs near Boulder Bay on Banks Peninsula collapsed. An uninjured family was rescued from the area by surf lifesavers via inflatable raft.{{Cite news |date=24 December 2011 |title=Family rescued after watching cliffs fall |url=https://www.stuff.co.nz/national/christchurch-earthquake/6186588/Family-rescued-after-watching-cliffs-fall |access-date=30 November 2024 |work=The Press}} The quake caused rock fall to occur from the Port Hills. Rock fall occurred in the suburbs of Sumner and Redcliffs, but the worst of it hit shipping containers used as protection against rock fall. The rock fall was not serious and did not immediately appear to affect any properties that had not been abandoned.{{Cite news |date=2 January 2012 |title=Hillside damage 'not as severe' |url=https://www.stuff.co.nz/the-press/news/christchurch-earthquake-2011/6206865/Hillside-damage-not-as-severe |access-date=30 November 2024 |work=The Press}} Because of the rock fall, residents were encouraged by police to keep away from the suburbs in the hills.{{Cite news |date=23 December 2011 |title=Large earthquakes hit Christchurch |url=https://www.smh.com.au/environment/large-earthquakes-hit-christchurch-20111223-1p7ya.html |access-date=1 May 2025 |work=The Sydney Morning Herald}}

After the earthquake at 1.58{{Nbsp}}pm, the ambulance service St John received approximately 140 emergency calls, and treated about 60 patients for issues that included falls, cardiac symptoms and anxiety attacks. One person died after tripping over ground that had become uneven due to the earthquake.{{Cite journal |last1=Abeling |first1=Shannon |last2=Horspool |first2=Nick |last3=Johnston |first3=David |last4=Dizhur |first4=Dmytro |last5=Wilson |first5=Nick |last6=Clement |first6=Christine |last7=Ingham |first7=Jason |date=2020-02-01 |title=Patterns of earthquake-related mortality at a whole-country level: New Zealand, 1840–2017 |url=https://journals.sagepub.com/doi/10.1177/8755293019878190 |journal=Earthquake Spectra |language=en |volume=36 |issue=1 |pages=150 |doi=10.1177/8755293019878190 |bibcode=2020EarSp..36..138A |issn=8755-2930}}File:Christ Church Cathedral 23.jpg five days before the December 2011 earthquake]]An unoccupied house collapsed, as well as a partially demolished building.{{Cite news |date=23 December 2011 |title=New Zealand's Christchurch hit by series of earthquakes |url=https://www.theguardian.com/world/2011/dec/23/new-zealand-earthquake-christchurch |access-date=1 May 2025 |work=The Guardian |agency=Associated Press}} A staircase in the Forsyth Barr Building collapsed; staircases in that building had already collapsed and had been damaged in the February earthquake.{{Cite news |date=12 June 2012 |title=Engineers finally able to access Forsyth Barr |url=https://www.stuff.co.nz/the-press/news/christchurch-earthquake-2011/7079907/Engineers-finally-able-to-access-Forsyth-Barr |access-date=30 November 2024 |work=The Press}} Minor damage occurred in the Christchurch Arts Centre. The rose window of Christ Church Cathedral, which had already been seriously damaged by the previous earthquakes, collapsed. The cathedral's western wall experienced more damage. The Hornby Clocktower building was "badly damaged" and had to be demolished in 2014.{{Cite news |date=17 September 2014 |title=Landmark building may come down |url=https://www.stuff.co.nz/the-press/news/christchurch-earthquake-2011/6496063/Landmark-building-may-come-down |access-date=3 May 2025 |work=The Press |publisher=Stuff}} Two of the Terrace on the Park apartment buildings suffered major damage, resulting in the complex being urgently demolished February 2012.{{Cite news |date=8 June 2012 |title=Apartments demolished at speed |url=https://www.stuff.co.nz/the-press/7066554/Apartments-demolished-at-speed |access-date=30 November 2024 |work=The Press}}{{Cite news |date=3 February 2012 |title=Urgent demolition for Park Terrace ordered |url=https://www.stuff.co.nz/the-press/news/christchurch-earthquake-2011/6357229/Urgent-demolition-for-Park-Terrace-ordered |access-date=30 November 2024 |work=The Press}} In March 2012, the damage at the University of Canterbury was estimated to be $1{{Nbsp}}million.{{Cite news |date=7 March 2012 |title=Schools' quake repairs to cost up to $150m |url=https://www.stuff.co.nz/the-press/news/christchurch-earthquake-2011/6533999/Schools-quake-repairs-to-cost-up-to-150m |access-date=30 November 2024 |work=The Press}} In total, the Earthquake Commission received over 48,000 damage claims. It had paid out $15.4 million by September 2012.{{Cite web |title=EQC Annual Report 2011-2012 |url=https://www.eqc.govt.nz/assets/Publications-Resources/EQC-Annual-Report-2011-12.pdf |website=Earthquake Commission |page=53}}

A state of emergency was declared in Canterbury and the National Crisis Management Centre was activated but was soon stood down.{{Cite web |title=Declared States of Emergency |url=https://www.civildefence.govt.nz/resources/previous-emergencies/declared-states-of-emergency |access-date=30 November 2024 |website=Civil Defence |language=en}} The City Council set up an Emergency Operations Centre in the city.{{Cite web |date=23 December 2011 |title=Christchurch earthquake Friday 23 December 2011 |url=https://www.dpmc.govt.nz/sites/default/files/2024-03/christchurch-earthquake-friday-23-december-2011.pdf |access-date=30 November 2024}} The council temporarily closed all of its properties. The council's civic offices on Hereford St was reopened on 10 January after it had to undergo "minor repairs".{{Cite news |date=5 January 2012 |title=Aftershocks hit council facilities |url=https://www.stuff.co.nz/the-press/news/christchurch-earthquake-2011/6214017/Aftershocks-hit-council-facilities |access-date=30 November 2024 |work=The Press}} Property owners were encouraged by Canterbury Earthquake Recovery Minister Gerry Brownlee and CERA executive Roger Sutton to re-check their buildings for damage.{{Cite news |date=3 February 2012 |title=December quake damage may not be known |url=https://www.stuff.co.nz/the-press/news/christchurch-earthquake-2011/6361393/December-quake-damage-may-not-be-known |access-date=30 November 2024 |work=The Press}} The Student Volunteer Army helped to clean up the liquefaction.

Christchurch Airport was evacuated on the day of the earthquakes and was closed for inspections. No runway damage was found{{Cite news |date=24 December 2011 |title=Airport shutdown sparks travel chaos |url=https://www.stuff.co.nz/national/christchurch-earthquake/6186575/Airport-shutdown-sparks-travel-chaos |access-date=30 November 2024 |work=The Press}} but "the terminal buildings were cleared of any damage". Flights continued at 6{{Nbsp}}pm. All the shopping centres were temporarily closed and evacuated as a precautionary measure.{{Cite news |date=24 December 2011 |title=Shops scramble to reopen tills |url=https://www.stuff.co.nz/national/christchurch-earthquake/6186332/Shops-scramble-to-reopen-tills |access-date=30 November 2024 |work=The Press}} Some retailers experienced revenue losses because they were unable to open or had delays opening on Christmas Eve, one of the busiest trading days of the year. The Palms did not re-open that day.

On 26 December, Prime Minister John Key said that "What we can conclude is that the most significant damage from the earthquakes is really the psychological damage and the impact on the confidence of the people of the Christchurch."

{{reflist}}

• [https://www.theguardian.com/world/gallery/2011/dec/23/christchurch-rocked-earthquakes-in-pictures Gallery of images] at The Guardian
• [https://web.archive.org/web/20120107205841/http://www.stuff.co.nz/national/christchurch-earthquake/photos/6184582/Christchurch-Earthquake-23-12 Galley of images] at Stuff

{{Earthquakes in 2011}}

{{Earthquakes in New Zealand}}

{{Christchurch earthquakes}}

{{DEFAULTSORT:Christchurch earthquake, December 2011}}

Category:2011 Christchurch earthquake

Category:2011 earthquakes

Category:December 2011 in New Zealand