#eqjp Tsunami marine and minor land threat warning in effect for NZ update 14
Saturday 12 March 2011, 9:26AM
By Civil Defence Emergency Management
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A tsunami marine and minor land threat warning is in effect for New Zealand:
The tsunami warning will remain in effect until a cancellation message is issued by MCDEM.
The Pacific Tsunami Warning Centre (PTWC) has issued a Tsunami Warning for New Zealand in response to the above earthquake. Confirmation has been received that a tsunami was generated. Wave heights of up to 4 metres have been measured in coastal Japan. Wave heights of 0.2 m have been observed in Nauru and Honiara.
New Zealanders with concerns about family in Japan
New Zealanders with concerns about family in Japan should try to contact them directly in the first instance. If you cannot make contact and they are known to be in the north east of Japan please contact the Ministry of Foreign Affairs and Trade on: 0800 432 111. If calling from overseas call +64 4 439 8000.
LATEST (0958hrs)
Summary: The Pacific Tsunami Warning Centre (PTWC) issued a Tsunami Warning for New Zealand in response to the above earthquake.
First arrivals have been measured by coastal gauges at the New Zealand coast. At Raoul Island first arrival was recorded at 0635 hours today and at North Cape at 0710 hours.
Additional arrival times have been detected for the upper North Island (see table below).
Initial wave amplitudes are in the order of 15cm but have been up to 30cm over the last two hours. It is important to note that higher wave amplitudes are expected to follow in the next couple of hours based on modelling.
The New Zealand Tsunami Expert Panel assessment is that there is a marine and minor land threat only for parts of the upper North Island coasts of New Zealand. See the attached threat level map and threat zone table for further details.
The Green and Blue shaded areas on the map indicate where a minor land and marine threat exists, respectively.
Threat Description
Based on real-time tsunami modelling and comparison with historical events, the interpretation is that a minor land threat (Green on the attached threat level map i.e. wave heights just over 1m) 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 (Blue on the attached threat level map, 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, around Coromandel Peninsula and Bay of Plenty to Gisborne.
Coastal areas not shaded (white on the map) are under no tsunami threat, however, unusual tidal surges may be observed and caution is advised.
A tsunami is a series of waves or surges and the first wave may arrive later and may not be the largest. The larger arrivals are anticipated from about 0800 NZDT and expected to last for several (at least five) hours.
Tsunami activity such as unusual currents and changes in sea-level will continue for several hours after first arrivals.
Tsunami wave heights cannot be accurately predicted and can vary significantly along a coast due to local effects.
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 marked Green and Blue on the Threat Level map 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.
NOTE: Unshaded (white) areas on the map are under no tsunami threat, however, unusual tidal surges may be observed and caution is advised.
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.
First arrival at North Cape indicates that actual arrival times may be up to an hour later than the modelled times published earlier.
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.
Tsunami Threat Level Map:
Tsunami Threat Level Map 3 - PDF (updated 0800 NZDT 12/03/2011) .pdf 145kb
Tsunami Threat Level Map 3 - JPEG (updated 0800 NZDT 12/03/2011) .jpg 166kb
We are now displaying coastal gauge readings rather than the modelled estimated arrival time. The approximate actual arrival times of detectable waves at North Island coastal gauges are as follows:
| Location | Actual Arrival Time |
| Chatham Islands | No arrival yet |
| North Cape | 0710NZDT 12 March 2011 |
| Great Barrier Island | 0740NZDT 12 March 2011 |
| Tauranga | 0750NZDT 12 March 2011 |
| East Cape | 0740NZDT 12 March 2011 |
| Gisborne | 0810NZDT 12 March 2011 |
| Napier | 0920NZDT 12 March 2011 |
| Castlepoint | No arrival yet |
(Earlier) Estimated Wave Arrival Times
| Location | Model Wave Arrival Time |
| Chatham Islands-Kaingaroa | 0753NZDT 12 March 2011 |
| Chatham Islands-Waitangi | 0753NZDT 12 March 2011 |
| North Cape | 0623NZDT 12 March 2011 |
| Whangarei | No information |
| Auckland (West) | 0723NZDT 12 March 2011 |
| Mt Maunganui | No information |
| East Cape | 0723NZDT 12 March 2011 |
| Gisborne | 0729NZDT 12 March 2011 |
| New Plymouth | 0808NZDT 12 March 2011 |
| Napier | 0817NZDT 12 March 2011 |
| Wanganui | No information |
| Wellington | 0753NZDT 12 March 2011 |
| Nelson | 1115NZDT 12 March 2011 |
| Marlborough Sounds | No information |
| Westport | 0837NZDT 12 March 2011 |
| Greymouth | No information |
| Lyttelton | 1003NZDT 12 March 2011 |
| Timaru | No information |
| Milford Sound | 0747NZDT 12 March 2011 |
| Dunedin | 0929NZDT 12 March 2011 |
| Bluff | 1020NZDT 12 March 2011 |
| Stewart Island | No information |
(Earlier) Estimated Wave Amplitudes
| Ahipara to Bay of Islands | 1 - 3 m |
| Cape Brett to Mangawhai | 0.2 - 1 m |
| North East Auckland Coast | 0.2 - 1 m |
| Great Barrier Island | 0.2 - 1 m |
| Auckland East Coast | 0.2 - 1 m |
| Coromandel Peninsula / West Coast /Firth of Thames | 0.2 - 1 m |
| Coromandel Peninsula / East Coast | 0.2 - 1 m |
| Western Bay of Plenty Coast | 0.2 - 1 m |
| Eastern Bay of Plenty Coast | 0.2 - 1 m |
| Gisborne North Coast | 0.2 - 1 m |
| Gisborne South Coast | 0.2 - 1 m |
| Wairoa Coast | < 0.2 m |
| Napier/Hastings Coast | < 0.2 m |
| Central Hawke's Bay Coast | < 0.2 m |
| Masterton / Tararua Coast | < 0.2 m |
| Wairarapa South Coast | < 0.2 m |
| Wellington South Coast | < 0.2 m |
| Wellington West / Kapiti Coast | < 0.2 m |
| Horowhenua / Manawatu / Rangitikei Coast | < 0.2 m |
| South Taranaki / Wanganui Coast | < 0.2 m |
| New Plymouth Coast | < 0.2 m |
| Waikato West Coast South | < 0.2 m |
| Waikato West Coast North | < 0.2 m |
| Auckland Region West Coast | < 0.2 m |
| Pouto Point to Reef Point | 0.2 - 1 m |
| Marlborough East Coast | < 0.2 m |
| Kakioura Coast | < 0.2 m |
| Hurunui Coast | < 0.2 m |
| Christchurch North Coast | < 0.2 m |
| Banks Penisula | < 0.2 m |
| Mid to South Canterbury Coast | < 0.2 m |
| Waitaki Coast | < 0.2 m |
| Dunedin Coast | < 0.2 m |
| Clutha Coast | < 0.2 m |
| Southland Coast | < 0.2 m |
| Stewart Island | < 0.2 m |
| Fiordland Coast | < 0.2 m |
| Westland Coast | < 0.2 m |
| Greymouth Coast | < 0.2 m |
| Westport Coast | < 0.2 m |
| Kahurangi Coast | < 0.2 m |
| Marlborough Sounds / Tasman Bay | < 0.2 m |
| Chatham Islands | 1 - 3 m |