National Advisory: Tsunami Potential Marine and Beach Threat
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No: 03
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Issued at 1720 hours on 06/02/2013

The Ministry of Civil Defence & Emergency Management (MCDEM) has issued a national advisory - tsunami potential marine and beach threat for Gisborne, Bay of Plenty, Auckland, North Cape, Waikato, Taranaki, Manawatu/Wanganui, Kapiti, Marlborough, Nelson/Tasman, West Coast, Milford, Dunedin and Chatham Islands.

People in the above coastal areas should:

1. Stay out of the water (sea, rivers and estuaries, including boating activities)
2. Stay off beaches and shore areas
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 local civil defence authorities

The attached map shows the estimated tsunami threat-level based on the anticipated maximum tsunami amplitudes for the New Zealand coastal zones.

Historical comparisons suggest that the amplitudes are likely to be greatest in the central west coast of New Zealand, between Hokitika and New Plymouth; and also in the far north of the North Island (Ahuriri Peninsula). Elsewhere it is anticipated that the threat lies towards the lower end of the Marine Threat (0.2-1.0 m amplitude) band.

Historical experience and modelling experience suggest that the largest waves will be several hours (~2-8 hours) after the first arrivals. The first arrivals are likely to be small.

In many locations the primary concern is likely to come from strong currents within harbours and surges in river mouths.

The tsunami potential threat will remain in effect until a cancellation message is issued by MCDEM.

Only messages issued by MCDEM represent the official warning status for New Zealand, not those issued by the Pacific Tsunami Warning Centre (PTWC).

This national advisory has been issued to all local civil defence authorities, emergency services, other agencies and media. Local civil defence authorities will interpret this information for their areas and advise public action via local radio stations.
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More Detail

Areas under ‘Marine and Beach Threat’: Expect unusually strong currents and unpredictable water flows near the shore. This means a threat to beach, harbour, estuary and small boat activities. The severity of currents and changing water flows will vary within a particular coastal area and over the period this warning is in effect. Current assessments indicate that coastal inundation (flooding of land areas near the shore) is not expected but this assessment may change.

Note:
• The wave amplitudes given indicate the largest expected wave activity at any coastal point in the particular coastal zone and at any time during the entire period this warning is in effect (tsunami activity will vary in a zone and with time; the first wave activity may also not be the largest).
• The given amplitudes do not include the local tidal or sea state at the time of tsunami activity.
• Local authorities will determine the implication of the expected wave heights for their areas and will decide on appropriate response actions (e.g. evacuations). Listen or check for this information from your local authority.
The first tsunami activity may reach New Zealand in the areas around North Cape at approximately 1805 NZDT. This may be later and the first activity may not be the most significant. Tsunami activity will continue for several hours and the threat must be regarded as real until this warning is cancelled.

This warning has been issued to all local civil defence authorities, emergency services, other agencies and media. MCDEM and scientific advisors are closely monitoring the situation to update this assessment. Information will be updated or repeated at least hourly until this warning is cancelled. Also see www.civildefence.govt.nz

We note the Pacific Tsunami Warning Centre (PTWC) has issued a Tsunami Cancellation for this event. PTWC messages do not represent the official warning status for New Zealand.
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Information for emergency managers

An earthquake has occurred with these parameters:
Origin time: 0112 ZULU 06 FEB 2013
NZ time: 1412 NZDT 06 FEB 2013
Co-ordinates: 10.9 SOUTH 165.1 EAST
Depth: 33 KM
Location: SANTA CRUZ ISLANDS
Magnitude: 8.0
The above magnitude is provisional and may be increased or decreased as more seismic data becomes available. Estimates of expected earliest wave arrival times are as follows:

Note: These times are provisional and based on the best information available. Arrival times may be as much as one hour later and may be adjusted in subsequent messages.
Location Earliest Wave Arrival Time
Chatham Islands-Kaingaroa No information available
Chatham Islands-Waitangi No information available
North Cape No information available
Whangarei No information available
Auckland East 1947 NZDT 06/02/2013
Mt Maunganui No information available
East Cape 1915 NZDT 06/02/2013
Gisborne 1939 NZDT 06/02/2013
New Plymouth 1951 NZDT 06/02/2013
Napier 2027 NZDT 06/02/2013
Wanganui No information available
Wellington (Kapiti) 2003 NZDT 06/02/2013
Nelson No information available
Marlborough Sounds No information available
Westport 2030 NZDT 06/02/2013
Greymouth No information available
Lyttelton No information available
Timaru No information available
Milford Sound 2020 NZDT 06/02/2013
Dunedin 2039 NZDT 06/02/2013
Bluff No information available
Stewart Island No information available

Estimates of expected threat levels are as per the attached map.

Local and regional/Group Civil Defence Emergency Management must:

1. Maintain activation of appropriate response coordination arrangements and communication processes
2. Keep potentially at-risk communities informed as appropriate
3. Maintain contact with the NCMC (CDEM Groups only)
4. Stand by for further information.

Local CDEM to act in coordination with regional/Group CDEM.

Local emergency services must establish and maintain active response coordination with respective local and regional/Group Civil Defence Emergency Management.

MCDEM has activated the Memorandum of Understanding (MoU) with public broadcasters to broadcast this warning.
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NCMC status

The National Crisis Management Centre (NCMC) is activated.

http://www.civildefence.govt.nz/
http://www.getthru.govt.nz/
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Further updates

Further updates with more information will be issued regularly until a cancellation is issued. All further updates will be communicated by MCDEM via the national warning system.
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Issued by

Message authorised by the National Controller, Civil Defence Emergency Management.
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End of Message

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