ChileQuake National Warning:Tsunami Threat to NZ Update18

As at 12:15 NZDT, 28 February 2010, wave activity as reported on tsunami gauges appears to have stabilised at the previously-reported levels (approximately 1.0 metres at the Chatham Islands, 0.3 metres at East Cape, Napier, Castlepoint, Tauranga and North Cape, and 0.4 metres in Gisborne). 

Tsunami propogation models and historic data indicate that larger waves may follow the initial wave arrival times by 6 to 12 hours. There may also be strong surges and rapid rises in sea level in some places. The situation continues to be closely monitored.

Location	Estimated Wave Arrival Time - Updated
Chatham Islands-Kaingaroa	0752 NZDT 28 February 2010 - arrived
Chatham Islands-Waitangi	0735 NZDT 28 February 2010 - arrived - height 1.0m
North Cape	0920 NZDT 28 February 2010 - arrived - height 0.3m
Whangarei	0945 NZDT 28 February 2010 - arrived
Auckland (North Head)	1052 NZDT 28 February 2010 - arrived
Mt Maunganui	0904 NZDT 28 February 2010 - arrived - height 0.3m
East Cape	0824 NZDT 28 February 2010 - arrived - height 0.3m
Gisborne	0829 NZDT 28 February 2010 - arrived - height 0.4m
New Plymouth	1126 NZDT 28 February 2010 - no reports or gauge data, but assumed to have arrived
Napier	0853 NZDT 28 February 2010 - arrived - height 0.3m
Wanganui	1020 NZDT 28 February 2010 - no reports or gauge data, but assumed to have arrived
Wellington	0855 NZDT 28 February 2010 - arrived
Nelson	1035 NZDT 28 February 2010 - no reports or gauge data, but assumed to have arrived
Marlborough Sounds (Tory Channel)	0908 NZDT 28 February 2010 - no reports or gauge data, but assumed to have arrived
Westport	1038 NZDT 28 February 2010 - no reports or gauge data, but assumed to have arrived
Greymouth	1020 NZDT 28 February 2010 - no reports or gauge data, but assumed to have arrived
Christchurch (New Brighton)	0935 NZDT 28 February 2010 - arrived
Timaru	0910 NZDT 28 February 2010 - no reports or gauge data, but assumed to have arrived
Milford Sound	0935 NZDT 28 February 2010 - no reports or gauge data, but assumed to have arrived
Dunedin	0900 NZDT 28 February 2010 - no reports or gauge data, but assumed to have arrived
Bluff	0928 NZDT 28 February 2010 - no reports or gauge data, but assumed to have arrived
Stewart Island	0951 NZDT 28 February 2010 - no reports or gauge data, but assumed to have arrived

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. A wave measuring 0.16 metres was recorded in Apia, Samoa and a wave measuring 0.10 metres in Nukualofa, Tonga. A 1.5 metre wave has been reported at Pitt Island in the Chatham Islands. Further arrival times and wave heights for New Zealand mainland coastal areas are noted in the table below.

Based on modelling and measured waves arriving in New Zealand, 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) still 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 still 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.

This warning has been issued to all local civil defence authorities, emergency services, other agencies and media.