Chatham Island Tsunami Evacuation Zones

This dataset shows the tsunami evacuation zones for the Chatham Islands Council, drawn in December 2017.

What do the zones mean?  The Red Zone is the shore exclusion zone, including beaches, estuaries, river mouths and Te Whanga Lagoon. Even if a tsunami is not big enough to flood land, it can cause strong and unusual currents in the water, and unpredictable surges onto beaches, which can knock people off their feet.  The Orange and Yellow Zones are land evacuation zones. The Orange Zone could be flooded in a large tsunami, and the Yellow Zone could be flooded in a rare, very large tsunami.  You need to move out of all zones if you feel an earthquake that is either long (shakes for more than a minute) OR strong (shaking so strong it is hard to stand up), without waiting for an official warning or for anyone else to tell you what to do – a tsunami may arrive from nearby.  In an official tsunami warning – when we have more time before the tsunami will arrive – you will be told which zones you need to move out of, depending on how big the tsunami is likely to be when it arrives.

How are the zones drawn? The area flooded a tsunami depends on many things – the size of the earthquake, the direction it is coming from and the tide level when the waves arrive. We can never say for sure exactly which areas will be flooded in a tsunami.   When drawing tsunami evacuation zones we consider many different tsunami scenarios. The evacuation zone boundaries are drawn further inland than the worst tsunami flooding we would expect in a 2500 year time frame – we’d rather err on the side of caution.   The zone boundaries often follow some sort of feature that is easy to see on the ground, like roads, so that you know whether you are in or out of the zone.

You can find more information on how and when to evacuate on the Chatham Islands Council website at www.cic.govt.nz, or visit the Chatham Islands Council office in Waitangi.

Data and Resources

Additional Info

Field Value
Theme ["geospatial"]
Author
Maintainer canterburymaps
Source http://opendata.canterburymaps.govt.nz/datasets/2bec607622e647e78cc39028535bcbb5_6
Created 2019-01-14T22:38:22.000Z
Date modified 2019-01-16T19:46:20.000Z
Language English
Spatial {"type": "Polygon", "coordinates": [[[-176.7985, -44.4106], [-176.2042, -44.4106], [-176.2042, -43.6485], [-176.7985, -43.6485], [-176.7985, -44.4106]]]}
Source Identifier http://opendata.canterburymaps.govt.nz/datasets/2bec607622e647e78cc39028535bcbb5_6
Record created July 16, 2020, Last Updated August 1, 2020