Earthquake, possible tsunami threat

There was been a 7.8 earthquake of the Solomon Islands an hour ago (followed by 5.5 and 5.2 aftershocks so far).

There is a potential tsunami risk to New Zealand, but no known imminent threat

It would be wise to be cautious about going anywhere near sea level at the top of the North Island until more is known.

How do you know if and when it’s safe? I don’t really know, apart from listening to news and checking Civil Defence.

Their national website says:

Tsunami

All of New Zealand is at risk of earthquakes and all of our coastline is at risk of tsunami. We can’t predict when one will happen, but we can protect ourselves and our family.

But also

No declared emergencies

Friday 9 Dec7:53 am

http://www.civildefence.govt.nz/tsunami/

Three hours earlier there was a 6.5 earthquake off the coast of California.

pacificearthquakes

No imminent ‘large aftershock’ threat

The multi region structure of Civil Defence showed it’s weakness again yesterday when West Coast Civil Defence warned people to prepare for a ‘large aftershock’, but this was talked down by the Ministry of Civil Defence and Geonet, who said their information had been misinterpreted.

West Coast Civil Defence have since retracted their warning.

Aftershocks are normal after large earthquakes. So far there have been over 5,000 aftershocks following the Culverden-Kaikoura-Seddon M7.8 earthquake on Monday last week.

6.30am update: 7 eq in last hour, 156 eqs in last 12 hrs ( only 2 over M4) and 5456 eqs since the M7.8 Kaikoura Earthquake – @Geonet

They seem to be following a normal pattern of reduced frequency and size with a few bigger  blips.

Geonet have made general predictions of aftershocks based on statistics, which includes the likelihood that there will be large aftershocks some time. But it is not possible to accurately predict how big, nor when.

Regardless of the uncertainty people throughout New Zealand should be prepared for any earthquake event.

Newshub: National Civil Defence says no imminent ‘large aftershock’ threat

West Coast Civil Defence Public Information Manager Andy Thompson earlier said the aftershock activity in the area been “suspiciously quiet”.

“The GeoNet seismograph drums have been very quiet for the last day or so and the normally higher aftershock sequence of large quakes has not been occurring in the Kaikoura area,” said a statement from West Coast Civil Defence.

West Coast Civil Defence regional manager Chris Raine said another worry is that an area in Arthur’s Pass slightly west of the divide has experienced a number of small tremors in the last few days.

He said it’s an area they have been monitoring closely, with Mr Thompson describing it as “highly sensitive”.

West Coast Civil Defence has staff on duty this weekend to be available in the case of aftershocks and the forecasted heavy rain that is expected to start tomorrow morning.

They are urging locals to stock up on enough food, water, cash and medicine to last a week, and to ensure they have an emergency plan in place.

“If an earthquake is so strong that people can’t stand up, or rolling lasts more than a minute, they should evacuate inland,” regional manager Chris Raine said.

 The problem isn’t with the advice, but with the warning of an imminent large aftershock in their region.

But GeoNet say the science they’re using to authenticate the warning is simply incorrect.

“Just because the drums have been quiet for a day means absolutely nothing,” GeoNet seismologist John Ristau said.

“We kind of want to distance ourselves from this – we don’t know why they’ve gone out and done this.”

Mr Ristau says it is not usually Civil Defence’s policy to issue a warning without checking in with them first.

“Civil Defence would talk to us, we advise them, and they would never release anything without talking to us.

“What [West Coast Civil Defence] have done is looked at our [seismograph] drums, and taken the information we’ve put out and made their own interpretations.”

The Ministry of Civil Defence’s head office was also bemused by what was put out by the West Coast offshoot when contacted by Newshub, with a spokesperson saying they’re not aware of any increased risk of a strong aftershock.

The spokesperson reiterated that they are in regular contact with GeoNet, and would seldom issue a warning without consulting them first.

@Geonet tweeted at 7:13 last night:

Reminder: We produce forecasts and scenarios NOT specific eq warnings regarding aftershocks. if you see an eq warning, it’s not from GeoNet

Followed by

Contrary to some reports the Ministry of Civil Defence has not issued an earthquake threat warning for West Coast

On Facebook yesterday at 7:18 pm::

Please share this with anyone you know who is worried.

Contrary to some reports there is no “imminent threat” to the West Coast from earthquakes. Neither have we issued an earthquake threat warning.

After a large earthquake there is always an increased likelihood of aftershocks, some of which may be large.

Remember: drop, cover and hold until the shaking stops.

If you feel a strong earthquake that makes it hard to stand up, or a rolling earthquake that lasts longer than a minute, or observe strange sea behaviour such as the sea level suddenly rising and falling, or the sea making loud and unusual should move immediately to high ground, or as far inland as possible.

Since Monday GeoNet have been issuing earthquake forecasts based on the best science they have available – their most recent one can be found here: http://info.geonet.org.nz/…/M7.8+Kaikoura+Quake%3A+Future+S…

 And they followed up at 22:05 pm:

On our previous post: West Coast Civil Defence Emergency Management have retracted their urgent warning around large aftershocks on the West Coast. Media ran their stories in good faith and we thank them for running clarifications.

Remember – after a large earthquake there is always an increased likelihood of aftershocks, some of which may be large. Check out our previous post for more advice on what to do in quake.

You can find the latest earthquake forecasts from the good folk at GeoNet

The disjointedness between Geonet, national Civil Defence and all the Civil Defence regions is messy and needs to be tidied up.

West Coast Civil defence have now retracted their urgent warning.

Stuff: Large aftershocks a possibility, but there are no ‘urgent warnings’

West Coast Civil Defence Regional manager Chris Raine initially refused to answer questions from the media about the release, saying he was not prepared but was dealing with the fallout with the ministry. 

From his home in Greymouth, he said he accepted people were concerned after the release was issued and apologised.

“I apologise. It was done in the best interests of the West Coast people,” he said.

“I withdraw the urgent warning completely.”

He added Thompson, who issued the release, may have “misinterpreted” the risk of aftershocks.

This is ridiculous. The only thing missing is a full moon.

Each local emergency management office was responsible for its region, Clifford said. The Ministry for Civil Defence was a “central coordinator” for emergency responses, she said.

“The West Coast have a responsibility for their community and they have acted in what they think is the best for their community,” Clifford said.

She urged people to follow the information and advice issued by GNS Science and the Ministry of Civil Defence.

“The press release that has come from West Coast was not sent on behalf of the ministry,” she said.

The current disjointed way that Civil Defence advises the public is hopeless. And poor.

The West Coast Civil Defence website gives no obvious indication of any of this, it seems to have all happened via media.

This is hopeless. Where should we look for up to date information and warnings on earthquakes? I have no idea.

The national Civil Defence website has general information but nothing specific. Their last News and events ‘new update’ is remarkably dated 10 November, before any of these earthquakes occurred.

We should all know exactly where to go online for the latest information and advice.