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| magnitude = 7.1 Mw 〔〔 | depth = 〔 | location = near Darfield, Canterbury | countries affected = New Zealand | tsunami = | aftershocks = ~9,300 (as of early January 2012) 〔http://www.canterburyquakelive.co.nz/〕 | casualties = 2 seriously injured, approximately 100 total injuries〔 | intensity = X (''Extreme'') 〔(【引用サイトリンク】url=http://quake.crowe.co.nz/QuakeMap/Single/?Index=6898 )〕 | PGA = 1.26'' g'' 〔 }} The 2010 Canterbury earthquake (also known as the Christchurch earthquake or Darfield earthquake) struck the South Island of New Zealand with a moment magnitude of 7.1 at on , and had a maximum perceived intensity of X (''Extreme'') on the Mercalli intensity scale.〔 Some damaging aftershocks followed the main event, the strongest of which was a magnitude 6.3 shock that occurred on 22 February 2011.〔 Because this aftershock was centred very close to Christchurch, it was much more destructive and resulted in the deaths of 185 people, and was felt from Invercargill to Wellington. The main shock caused widespread damage and several power outages, particularly in the city of Christchurch, New Zealand's second largest city. Two residents were seriously injured, one by a collapsing chimney and a second by flying glass.〔〔 One person died of a heart attack suffered during the quake, although this could not be directly linked to the earthquake.〔〔 Mass fatalities were avoided partly due to there being few houses of unreinforced construction, although this was also aided by the quake occurring during the night when most people were off the street.〔 The earthquake's epicentre was west of Christchurch,〔 near the town of Darfield. The hypocentre was at a shallow〔 depth of 10 km.〔 A foreshock of roughly magnitude 5.8 hit five seconds before the main quake,〔 and strong aftershocks have been reported,〔 up to magnitude 6.3. The initial quake lasted about 40 seconds,〔 and was felt widely across the South Island, and in the North Island as far north as New Plymouth. As the epicentre was on land away from the coast, no tsunami occurred. The National Crisis Management Centre in the basement of the Beehive in Wellington was activated, and Civil Defence declared a state of emergency for Christchurch, the Selwyn District, and the Waimakariri District, while Selwyn District, Waimakariri and Timaru activated their emergency operation centres. Initially, a curfew was established for parts of Christchurch Central City from 7:00 pm to 7:00 am in response to the earthquake. The New Zealand Army was deployed to the worst affected areas in Canterbury.〔 Claims from the earthquake were confirmed at being between $2.75 and $3.5 billion NZD. ==Geological-background== In the first eighty years of European settlement in Christchurch (1850–1930), four earthquakes caused significant damage, the last of them centred at Motunau on the North Canterbury coast in 1922. Modelling conducted for the New Zealand Earthquake Commission (EQC) in 1991 found that earthquakes with a Mercalli intensity of VIII (significant property damage, loss of life possible) could recur on average in the Christchurch area every 55 years. The study also highlighted the dangers of soil liquefaction of the alluvial sediments underlying the city, and the likelihood of significant damage to water, sewer and power supply services. About 100 faults and fault segments have been recognised around the region, some as close as 20 km to central Christchurch. The closest faults to Christchurch capable of producing powerful earthquakes are found in the Rangiora-Cust area, near Hororata, and near Darfield. However, the 2010 quake occurred on a previously unknown fault. Scientists are investigating whether the main 2010 quake may have actually been two or three almost simultaneous earthquakes. The main quake occurred as a result of strike-slip faulting within the crust of the Pacific plate, near the eastern foothills of the Southern Alps at the western edge of the Canterbury Plains. The earthquake epicentre is located about to the south and east of the current surface expression of the Australia–Pacific plate boundary through the island (the Alpine and Hope Faults).〔 Though removed from the plate boundary itself, the earthquake likely reflects right-lateral motion on one of a number of regional faults related to the overall relative motion of these plates and may be related to the overall southern propagation of the Marlborough Fault System in recent geologic time.〔 The peak ground acceleration measured near Darfield was 1.26''g'' (12.36 m/s2), recorded near Darfield. This was considered by GNS scientists as an "extremely rare seismic recording made near a fault rupture". However, the February 2011 Christchurch earthquake experienced PGA of 2.2 ''g''. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「2010 Canterbury earthquake」の詳細全文を読む スポンサード リンク
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