#Tsunami Advisory 4
1945 hours Wednesday 6 February 2013
Tsunami: Potential Marine and Beach Threat remains in force for selected coastal areas of New Zealand
The Ministry of Civil Defence & Emergency Management (MCDEM) issued a national advisory at 17.20pm 6 February 2013 for parts of New Zealand's coast from Taranaki to Milford Sound.
The New Zealand Tsunami Expert Panel has advised that the potential marine and beach threat is likely to last through the early hours of Thursday 7 February 2013. The threat is judged to be low, likely to be undetectable except in enclosed bays that traditionally have abnormal current flows. See the attached map for affected areas.
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 (.jpg) 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. 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 marine and beach 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.