Tsunami from Japan earthquake – 11th March 2011, 10pm

Updated at: 12th March 2011, 9am

The Pacific Tsunami Warning Centre (PTWC) has issued a Tsunami Warning for New Zealand in response to the earthquake in Japan.  The New Zealand Tsunami Expert Panel assessment is that this is a marine threat only for New Zealand. A Marine Threat means strong and unusual currents are possible in the sea, rivers and estuaries.  No Land Threat is expected at this time.

The first wave arrived at the North cape at around 710 hrs and had an amplitude in the order of 15cm. It is important to note that, based on modelling, higher wave amplitudes are expected to follow over the next few hours.

Based on real-time tsunami modelling and comparison with historical events, the interpretation is that a minor land threat (i.e. wave heights just over 1 m) now exists in Northland between Ahipara and the Karikari Peninsula as well as in the Bay of Islands and the Chatham Islands. A minor land threat means there is a small potential for impacts on beaches in these areas. A marine threat (i.e. threat to the coastal marine area and small boats) remains in place for the northern North Island from Kaipara to Ahipara and south of the Karikari Peninsula to Gisborne. Unusual tidal surges may be observed in other parts of the country.

Waves will continue for several hours.

People in coastal areas should:

  1. Stay off beaches
  2. Stay out of the water (sea, rivers and estuaries, including boating activities)
  3. Do not go sightseeing
  4. Share this information with family, neighbours and friends
  5. Listen to the radio and/or TV for updates
  6. Follow instructions of your local Civil Defence authorities.

MCDEM and scientific advisors are closely monitoring the situation to determine the severity of the threat to New Zealand.

  1. Local and regional/Group Civil Defence Emergency Management must:
  2. Maintain activation of appropriate response coordination arrangements and communication processes
  3. Keep potentially at-risk communities informed as appropriateMaintain contact with the NCMC (CDEM Groups only)
  4. Stand by for further information.

Local CDEM to act in coordination with regional/Group CDEM.

Local emergency services must establish and maintain active response coordination with respective local and reginoal/Group Civil Defence Emergency Management.

MCDEM is continuing activation of the Memorandum of Understanding (MoU) with public broadcasters to broadcast this warning.

Only messages issued by MCDEM represent the official warning status for New Zealand.  Local civil defence authorities may supplement these messages by applying local threat assessments. Please visit the MCDEM website for further information.

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