2007 Gisborne earthquake explained

2007 Gisborne earthquake
Timestamp:2007-12-20 07:55:15
Anss-Url:usp000fuvt
Isc-Event:13293317
Local-Time:8:55 pm NZDT (UTC+13)
Magnitude:6.7
Pga:0.28 g
Depth:33km (21miles)
Engvar:en-UK
Location:-38.89°N 178.54°W
Countries Affected:New Zealand
Casualties:1 dead, 11 injured

The 2007 Gisborne earthquake occurred under the Pacific Ocean about off the eastern coast of New Zealand's North Island at 8:55 pm NZDT on 20 December. With a moment magnitude of 6.7 and maximum Mercalli intensity of VII (Very Strong), the tremor affected the city of Gisborne and was felt widely throughout the country, from Auckland in the north to Dunedin in the south.[1]

Tectonic setting

New Zealand lies along the boundary between the Australian and Pacific plates.

Earthquake

The earthquake occurred at 8:55 pm on 20 December 2007 off the coast of Gisborne, at a depth of about 40 kilometres. Shaking mostly affected Gisborne, but was felt throughout the country, from Auckland to Dunedin. Small appliances or furniture slipped or fell as far south as Wellington.

Effects

While the earthquake was initially reported to have caused no deaths, an elderly woman in Gisborne suffered a heart attack and died shortly after the quake.[3] A number of buildings in central Gisborne were damaged and had their roofs cave in. The central business district was closed off to allow building inspectors to assess buildings for damage; three buildings had collapsed. Gisborne's standby sewage system was activated. There were power outages immediately after the earthquake hit.[4] Temporary problems with phone, water and gas lines also occurred.[5] The town clock stopped at 8:55 pm.[6] The Earthquake Commission had received over 6,200 insurance claims costing a total of about $25 million, the biggest number since the 1987 Edgecumbe earthquake.[7] It was earlier estimated that the cost of damage caused by the earthquake could rise to $30 million.[8]

The National Crisis Management Centre was activated after the earthquake struck.

Liquefaction occurred near the Waipaoa River, and there was an increased activity in nearby mud volcanoes.[9]

See also

External links

Notes and References

  1. https://www.geonet.org.nz/earthquake/story/2839343 M 6.7, Gisborne, 20 December 2007
  2. Mouslopoulou, V., Nicol, A., Little, T. A., & Walsh, J. J. (2007). Terminations of large strike-slip faults: an alternative model from New Zealand . Geological Society, London, Special Publications, 290 (1), pp 387–415.
  3. http://www.nzherald.co.nz/section/1/story.cfm?c_id=1&objectid=10483683 One dead, up to 20 injured after huge quake
  4. News: 21 December 2007 . Quake 6.8 magnitude hits east coast . dead . https://web.archive.org/web/20071231163447/http://tvnz.co.nz/view/page/1320238/1517721 . 31 December 2007 . 29 July 2024 . 1 News.
  5. News: 21 December 2007 . Woman's death blamed on NZ quake . 29 July 2024 . ABC News.
  6. http://www.3news.co.nz/Rattled-Gisborne-residents-pick-up-the-pieces-after-quake/tabid/209/articleID/42241/cat/167/Default.aspx 'Rattled Gisborne residents pick up the pieces after quake'
  7. Earthquake Commission Annual Report 2007–2008 . 31 July 2024 . 6,7 . 24 June 2024 . https://web.archive.org/web/20240624071808/https://www.eqc.govt.nz/assets/Publications-Resources/EQC-Annual-Report-2007-08.pdf . live .
  8. http://www.stuff.co.nz/4332985a11.html The $30m shockwave
  9. Web site: 4 December 2008 . The Mw 6.6 Gisborne Earthquake of 2007: Preliminary Records and General Source Characterisation . New Zealand Society for Earthquake Engineering.