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Tsunami Threat to New Zealand - Marine threat confirmed #5

Saturday, 12 March 2011 12:29 a.m.

A tsunami marine warning is in effect for New Zealand:
The tsunami warning will remain in effect until a cancellation message is issued by MCDEM.
An earthquake has occurred with these parameters:
Origin time: 0545Z 11 March 2011
NZ time: 1846NZDT 11 March 2011
Co-ordinates: 38.2 North 142.5 East
Depth:  24km
Location: Near East Coast of Honshu, Japan
Magnitude:  8.9
The above magnitude is provisional and may be increased or decreased as more seismic data becomes available.   
Bay of Plenty Civil Defence Emergency Management Group has activated and is monitoring the situation.

The Pacific Tsunami Warning Centre (PTWC) has issued a Tsunami Warning for New Zealand in response to the above earthquake. The New Zealand Tsunami Expert Panel assessment is that there is a marine threat only for New Zealand. 

A marine threat means strong and unusual currents are possible in the sea, river mouths and estuaries, and unusual wave activity is possible at the beach.  No land threat is expected to the Bay of Plenty at this time.  
Confirmation has been received that a tsunami was generated.  Wave heights of up to 4 metres have been measured in coastal Japan. 

Based on real-time tsunami modelling and comparison with historical events, the interpretation is that a minor land threat (i.e. 1-3m wave heights) now exists in Northland between Ahipara and the Karikari Peninsula as well as in the Bay of Islands and the Chatham Islands. A marine threat (i.e. threat to beach and small boats) remains in place for the northern North Island from Kaipara to Ahipara and south of the Karikari Peninsula to Gisborne.

See the attached threat level map and threat zone table for further details. The first wave to arrive to New Zealand will be in the area around North Cape at approximately 0623NZDT 12 March 2011.

The first wave may arrive later and may not be the largest. The largest arrivals are anticipated from 0800 NZDT and to last for several (at least five) hours. Wave height refers to maximum water level relevant to the normal sea level at the beach.

Tsunami activity such as unusual currents and changes in sea-level will continue for several hours. 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.
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. This warning has been issued to all local civil defence authorities, emergency services, other agencies and media.

Bay of Plenty Civil Defence Emergency Management Group information

Bay of Plenty Civil Defence Emergency Management Group has activated and is monitoring the situation.

The expected arrival time in the Bay of Plenty is about 7.20am

The Whakatāne River Bar has been declared unworkable.

For more media information please contact Bronwyn Campbell, Group Public Information Manager on 021 287 9380.


Tauranga-Western Bay Civil Defence Information

An earthquake has struck off the coast of Japan.  The magnitude was 8.9

A tsunami warning has been issued for the northern coastlines of New Zealand.

This is a marine threat only - meaning that it is unlikely to have major land effects.   A marine threat means strong and unusual currents in the sea and in estuarine areas.

The main message for the public right now is to stay away from the beaches and waterways - this includes all boating activity.

The Coastguard and Surf Lifesaving people are being alerted.  There will be staff at boat ramps before dawn advising people not to launch boats.

Note:  the national Surf Life Saving Championships are being held at Mount Maunganui main beach starting tomorrow.   We will advise on any cancellation of these.

Share this information with family and friends.   Listen for updates on your local radio stations.

Elizabeth Hughes
Public Information Manager
027 277 1259

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