New Zealand Civil Defence Update on Tsunami Wave Heights and Arrival Times

#ChileQuake National Warning:Tsunami Threat to NZ Update 15

09:15HRS NZDT 28 Feb 2010

As at 09:15 NZDT, 28 February 2010, wave activity as reported on tsunami gauges is now approximately 0.5 metres at the Chatham Islands, and 0.2 metres at East Cape.

Rana Solomon of Chatham Islands Council reports a wave height of 1.5 metres at Pitt Island in the Chathams.

Gisborne, Napier and Castlepoint tsunami gauges are also showing initial activity of approximately the same magnitude as East Cape.

It is important to note that these are the first arrivals and larger waves may follow over a period of several hours.

The situation continues to be closely monitored.

Location Estimated Wave Arrival Time - Updated

Chatham Islands-Kaingaroa 0752 NZDT 28 February 2010
Chatham Islands-Waitangi 0735 NZDT 28 February 2010
North Cape 0920 NZDT 28 February 2010
Whangarei 0945 NZDT 28 February 2010
Auckland (North Head) 1052 NZDT 28 February 2010
Mt Maunganui 0904 NZDT 28 February 2010
East Cape 0824 NZDT 28 February 2010
Gisborne 0829 NZDT 28 February 2010
New Plymouth 1126 NZDT 28 February 2010
Napier 0853 NZDT 28 February 2010
Wanganui 1020 NZDT 28 February 2010
Wellington 0855 NZDT 28 February 2010
Nelson 1035 NZDT 28 February 2010
Marlborough Sounds (Tory Channel) 0908 NZDT 28 February 2010
Westport 1038 NZDT 28 February 2010
Greymouth 1020 NZDT 28 February 2010
Christchurch (New Brighton) 0935 NZDT 28 February 2010
Timaru 0910 NZDT 28 February 2010
Milford Sound 0935 NZDT 28 February 2010
Dunedin 0900 NZDT 28 February 2010
Bluff 0928 NZDT 28 February 2010
Stewart Island 0951 NZDT 28 February 2010

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.

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.

Confirmation has been received that a tsunami was generated. A wave measuring 2.34 metres was measured at Talcahuano, Chile and 0.35 metres at Easter Island, Chile, and at this stage, 0.2 metres in the Chatham Islands.

The first wave to arrive to the New Zealand mainland will be in the areas around East Cape and Gisborne at approximately 08.25NZDT, Sunday 28 February 2010.

The first wave may arrive later and may not be the largest.

Strong currents and unusual tidal effects may continue for several hours.

Based on preliminary modelling and comparison with historical events the interpretation of the Tsunami Experts Panel is that a marine threat (i.e. threat to beach and small boats corresponding to wave heights less than 1 metre) exists for the entire east coasts of the North and South Island from Puysegur around to Cape Reinga and extending south to Ahipara. Some land threat also exists for the Chatham Islands and Banks Peninsula i.e. wave heights between 1 and 3 metres. There may be some small observable sea level changes on parts of the west coast of both islands.

Wave heights refer to maximum water level relative to the normal sea level at the beach. This does not take tides into account. Based on historical events it is expected that the greatest wave heights could occur between 6 and 12 hours after the initial arrivals.

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.

Please DO NOT call 111 for tsunami updates. Updates will be posted on the NZ Civil Defence website. Local and regional information is available from city, district and regional councils.

Civil defence advice on what to do to be better prepared for tsunami

Note from SailRaceWin: Geonet has charts of tsunami gauge recordings around New Zealand, on which the arrival of the tsunami in the Chatham Islands and down the east coast of the North Island is already visible.

NZ Civil Defence