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A tsunami is a series of seismic sea waves
generated by movement on the ocean floor (either by earthquakes or large
underwater landslides).
The Pacific Tsunami Warning Centre is based in
Honolulu, Hawaii. When a strong earthquake occurs in the Pacific
area, New Zealand and other members of the Pacific Tsunami Warning System are
notified by the centre in Honolulu.
A "tsunami watch" is commenced, and continues until either a tsunami is
confirmed as having developed, or until it is certain that no danger exists.
The first positive indication that a tsunami
exists usually comes from the tidal report station nearest the disturbance.
When confirmation is received that a tsunami exists, the Pacific Tsunami Warning
Centre issues a tsunami warning. When a tsunami warning is received,
the Ministry for Emergency Management issues a national warning through the
Police to Civil Defence organisations, and through nation-wide radio and
television broadcasts.
When a warning is issued - follow
the instructions that are given.
A "near source" tsunami is one that is generated
close to a coastline by a strong earthquake. (New Zealand has experienced a few
of these in the past). The water level may fall very quickly past
the normal low tide mark. Then it may return just as quickly.
If this happens there won’t be enough time to issue a warning.
Things to know
before a Tsunami strikes:
- Know the Civil Defence warning signal for your
area
- Know how to reach the nearest safe ground
- Form a survival plan for;
... Your family
... Your pets
- Maintain your disaster survival kit
- Know how to turn off electricity and gas
supplies at the mains
When a Tsunami
threatens
KNOW WHAT TO DO BEFORE YOU
HAVE TO DO IT!
Tsunamis can occur anywhere in
the Pacific where there is an undersea earthquake or landslide.
Seismographs and tide stations throughout the Pacific pinpoint the site of the
earthquake or landslide. This information is then passed to the
Pacific Tsunami Warning Centre in Honolulu, and then details of the tsunami,
once confirmed, are issued to all stations in the Pacific.
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