Two Significant ‘Foreshocks’ Strike Christchurch, NZ

Strong Foreshocks Measuring 6.4 and 5.7Mw Rattle Christchurch, NZ: Report

The following are preliminary details of the shocks as recorded by GFZ Potsdam Earthquake Bulletin

The first shock measuring 6.4Mw was followed by a less powerful event measuring 5.7Mw about 11 minutes later. Both events occurred at a depth of about 5km, the report indicates.

The quakes occurred about 10km SE of Christchurch [ in the middle of the Lyttelton harbor,] NZ’s second largest city.

Event No. 1

GFZ Potsdam – Earthquake Bulletin
Region: South Island, New Zealand
Time: 2011-02-21 23:51:44.5 UTC
Magnitude: 6.4
Epicenter: 172.83°E 43.40°S
Depth: 5 km
Status: automatic

© Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum – GFZ

Event No. 2

GFZ Potsdam – Earthquake Bulletin
Region: South Island, New Zealand
Time: 2011-02-22 00:04:20.8 UTC
Magnitude: 5.7
Epicenter: 172.68°E 43.52°S
Depth: 5 km
Status: automatic

There are reports of buildings collapsing with possible fatalities,  media reported. The Christchurch Hospital is being evacuated.

“But Twitter users have reported feeling the quake as far as Wellington and Dunedin, with the violent episode lasting at least a minute and rocking buildings,” a report said.

A photo posted by gavb online showing damage at Sumner. Photo credit: Twitpic (via Herald Sun)

Christchurch Cathedral didn’t make it this time. (twitpic.com/42dzk8: Tess Woolcock)

USGS reported the shocks as measuring 6.3Mw and 5.6Mw, and listed the following details:

Event #1

• Magnitude: 6.3
• Date-Time:
  • Monday, February 21, 2011 at 23:51:42 UTC
  • Tuesday, February 22, 2011 at 12:51:42 PM at epicenter

• Location: 43.513°S, 172.638°E   (Later revised to 43.600°S, 172.710°E)
• Depth: 4 km (2.5 miles)
• Region: SOUTH ISLAND OF NEW ZEALAND
• Distances (NEAR Christchurch, New Zealand)
  • 215 km (135 miles) SSE of Westport, New Zealand
  • 305 km (190 miles) SW of WELLINGTON, New Zealand
  • 315 km (195 miles) NNE of Dunedin, New Zealand

• Location Uncertainty: horizontal +/- 13.9 km (8.6 miles); depth +/- 0.5 km (0.3 miles)
• Source: USGS NEIC (WDCS-D)
• Event ID: usb0001igm

Event #2

• Magnitude: 5.6
• Date-Time: Tuesday, February 22, 2011 at 00:04:18 UTC
• Location: 43.580°S, 172.798°E
• Depth: 6.7 km (4.2 miles)
• Distances: 10 km (5 miles) ESE of Christchurch, New Zealand
• Location Uncertainty: horizontal +/- 13 km (8.1 miles); depth +/- 0.2 km (0.1 miles)

FIRE-EARTH has previously posted specific advice concerning the threat of seismic hazards to New Zealand. [Ask NZ Govt and Google why they buried the information.]

Powerful Quake Strikes Christchurch, NZ

Excerpts from Local News Reports:

• “The Christchurch police central police station has been evacuated, the airport has been closed and there are reports of collapses of many buildings, including a church in the central city.” Source
• “Damage in the city is severe. There are reports of bodies being pulled from a bus in Columbo Street.” Source
• “Multiple fatalities have been reported at several locations in the central city, including two buses crushed by falling buildings,” the police website said.

Major earthquake in Christchurch

22 February, 2011 – 13:55

A major earthquake in Christchurch at 12.51pm has caused widespread damage and injury.

The central city is currently being evacuated as reports are received of widespread damage to buildings and infrastructure.

Multiple fatalities have been reported at several locations in the central city, including two buses crushed by falling buildings. A doctor and emergency services are attending.

Other reports include multiple building collapses, fires in buildings in the central and persons reported trapped in buildings.

All available police staff are assisting with evacuations and emergency responses.

Christchurch Hospital is not evacuated and is in operation. No injuries reported at Christchurch Airport.

Defence forces have been called in to assist.

IMPORTANT MESSAGES:

Triage centres have been established for people with injuries at:

– Latimer Square, Central City
– Spotlight Mall, Sydenham
– Sanitarium, Papanui

Police advise that people who have evacuated their homes or buildings should report to their nearest Civil Defence sector post – usually schools.

Further updates will be issued as available.

A media briefing will be advised as soon as possible later today. ENDS

Stephen Hill, Police District Communications Manager
Mob. 027 4363701  — MEDIA PLEASE NOTE: Cellphone services may be unavailable.

Related Links

• New Zealand Region Earthquake Warning
• Powerful Quake Strikes Christchurch, NZ

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• Strong Quake Strikes Off Coast of NI, NZ
• Mt Ruapehu Eruption Alert
• Mag 5.3 Earthquake Rattles North Island, NZ
• Magnitude 7 Earthquake Hits Kermadec Islands

• Magnitude 6.8 Quake strikes Kermadec Isls Region
• Powerful 7.8 M Quake Strikes New Zealand Region
• http://newzeelend.wordpress.com/2009/05/09/a-warning-to-new-zealand-visitors/
• Earthquake Cluster Zone Closing in on New Zealand Posted on October 6, 2008

• FEWW Volcano Links
• Volcanoes
• FEWW Earthquake Links