Update 2: 18 September 2015, 2 pm
The Ministry of Civil Defence & Emergency Management has cancelled the National Tsunami Warning (Marine and Beach Threat) issued yesterday after the earthquake near Chile.
“We have reviewed the situation following advice from the GeoNet Tsunami Experts Panel and believe the National Warning no longer needs to be in place as the threat to New Zealand’s East Coast and Chatham Islands has largely passed,” says Sarah Stuart-Black, Director, Ministry of Civil Defence & Emergency Management.
“We expect that there may be some unusual water conditions for the next 24-36 hours and advise people to be cautious and use discretion before going into the water or going out in small boats. We expect things to be back to normal within that 36 hour period,” she says.
The Tsunami Warning (Marine and Beach Threat) was issued at midday on Thursday, 17 September, with the first waves arriving at the Chatham Islands from 11:50 pm on Thursday.
Wave heights were up to 50 cm, which were recorded in parts of the Chatham Islands.
“The response from the public to this warning has been fantastic. In most cases we’ve seen people heeding our advice and being responsible,” says Mrs Stuart-Black.
“On any given day New Zealand’s entire coastline could be at risk from a tsunami. This warning as a result of the Chilean earthquake is a reminder to each of us to make sure we know what to do in an emergency.
“We want every New Zealander to be prepared for an emergency. They need to have a household emergency plan for what to do.
“In the past few years we have experienced several of these ‘distant source’ tsunami that have been generated from earthquakes from across the Pacific. People should be getting a better understanding of what happens, and what to do,” says Mrs Stuart-Black.
If there is a ‘local source’ tsunami caused by an earthquake near our coast, it may not be possible to give an official warning. We need to take notice of natural warnings. Things like:
- The ground shaking so much from an earthquake that it’s hard to stand up
- A rolling earthquake of a minute or more
- The sea doing something different - like a sudden rise or fall in the sea level or the sea making loud and/or unusual noises (it might sound like a roaring jet engine)
If people experience these things, then they need to move immediately to high ground or as far inland as possible. Once they’ve done that, they need to listen to the radio or other media for information from local civil defence authorities.
Update: 18 September 2015, 9 am
The Ministry of Civil Defence & Emergency Management reports that the first tsunami wave following the earthquake in Chile reached New Zealand just before midnight (11:50 pm) at the Chatham Islands.
In the Chatham Islands, waves of around 50 cm were experienced in places, repeated ebbing and flowing of the tide, along with ocean noises associated with tide surge. A few families in who live two-to-three metres off shore self-evacuated.
Minor fluctuations in sea-level have been recorded in North Cape, Great Barrier Island, Tauranga, East Cape, Gisborne, Napier, Castlepoint, Wellington, Kaikoura, Christchurch. These have been estimated to be no more than 30 cm.
The wave heights have been within those anticipated by the Tsunami Expert Panel.
As it gets lighter, local Civil Defence Emergency Management Groups will be assessing their regions.
Unusual marine and coastal activity can be expected for around 24 hours after the first wave. There could be continued unpredictable activity, ebbing and flowing and strong currents.
The national warning remains in place. People in coastal areas of the Chatham Islands and the East Coast of New Zealand should continue to:
- Stay out of the water (sea, rivers and estuaries, including boating activities)
- Stay off beaches and shore areas
- Do not go sightseeing
- Share this information with family, neighbours and friends
- Listen to the radio and/or TV for updates
- Follow instructions of local civil defence authorities
The Tsunami Expert Panel will be convening this morning, and a further update will be provided afterwards.
17 September 2015
Bay of Plenty Civil Defence is urging people in coastal areas of the Bay of Plenty to keep away from beaches, coastal areas and river mouths in the coming 24 hours.
The Ministry of Civil Defence & Emergency Management (MCDEM) has issued a tsunami warning (marine and beach threat) for Chatham Islands and the East Coast of New Zealand. Wave heights of between 0.2-1 metre can be expected for much of the East Coast of New Zealand and Chatham Islands.
People in the affected coastal areas should:
- Stay out of the water (sea, rivers and estuaries, including boating activities)
- Stay off beaches and shore areas
- Do not go sightseeing
- Share this information with family, neighbours and friends
- Listen to the radio and/or TV for updates
- Follow instructions of local civil defence authorities
The first tsunami activity may reach the East Cape at approximately 1.21am on 18 September 2015. It is expected to bring unusually strong currents and unpredictable water flows near the shore. Current assessments indicate that coastal inundation (flooding of land areas near the shore) is not expected, but this assessment may change.
Bay of Plenty Civil Defence Group Controller Clinton Naude said that it’s likely there will be tidal surges and unsettled seas tonight and throughout the day tomorrow.
“We recommend that people stay out of the water and away from coastal areas. Whitebaiters should take extra care too – they may not be fishing on the coast but tidal surges could create unusual currents and rising water levels in the lower reaches of our local waterways," Mr Naude said.
The tsunami warning will remain in effect until a cancellation message is issued by MCDEM.
Regular updates will be provided on Bay of Plenty Civil Defence Emergency Management’s website www.bopcivildefence.govt.nz and on www.facebook.com/BOPCivilDefence.