Skip to main content

Tsunami threat to New Zealand Marine threat confirmed 4

Saturday, 12 March 2011 12:39 a.m.

Release No: 4

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 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 preliminary modelling and comparison with historical events the interpretation is that a marine threat (wave heights up to 1 metre) exists for northern North Island from Kaipara around to Gisborne as well as the Chatham Islands. Wave height refers to maximum water level relevant to the normal sea level at the beach. Notably, first arrivals are expected at low tide in the northern North Island. 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. 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
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, Public Information Manager on 021 287 9380.