Potential tsunami on NZ east coast

Updated at 9:05am.

Initial indication is that some tsunami activity is being registered in the Chatham Islands. The latest information from the Chatham Islands is that the height of the first wave is 20 centimetres above normal sea level. The impact of this is likely to be minimal.

After the initial wave, the water level then dropped by a total of around a metre. Further waves are being observed, and are at a similar height, or possibly slightly higher, than the first wave.

Historical information shows that tsunami waves from South America are generally lower in the Banks Peninsula and Christchurch than in the Chatman Islands. The situation will be monitored for the rest of the day, and the situation may change as further information becomes available. Residents are advised to await instructions from their local authorities.

Based on the current information Banks Peninsula bays residents are not required to evacuate at this stage, but need to monitor any updates. If a evacuation warning needs to be issued residents will have at least two hours warning to evacuate.

The warning to stay away from the foreshore, estuaries and river mouths and to prepare for possible evacuation remains in place.

Detailed evacuation and safety advice will be provided from local Civil Defence. People need to take:

Essential medicines, toilet items and baby needs,

Important Documents,

Radio and torch (with batteries),

Emergency bottled water,

Extra clothing and footwear.

Residents in all coastal areas, particularly Christchurch suburbs around the estuary and Banks Peninsula communities, should:

Stay off beaches

Stay out of the water (sea, rivers and estuaries, including boating activities)

Do not go sightseeing – people gathering at beaches will be moved on

Share this information with family, neighbours and friends

Listen to official radio and/or TV stations for updates (emergency radio stations are listed at the back of the Yellow Pages)

Follow instructions of your local Civil Defence authorities.

Farmers are advised to move stock to higher ground.