Many Aucklanders were lightly shaken awake just after midnight this morning when a 7.5 magnitude earthquake hit near Culverden in North Canterbury.
While some of us turned over and went back to sleep, or didn’t notice it at all, the Auckland Civil Defence and Emergency Management (CDEM) team swung into action.
Duty Officer Matthew Bramhall was alerted to the South Island shake seconds after it happened and immediately activated the CDEM first response conference call.
“We have a very useful system that phones a group of people from across the Civil Defence team so that we can immediately share information and work out what’s needed in terms of a response.
“This morning, we were all on the phone by 12.08am, six minutes after the quake struck, and were ready to get a message out to Aucklanders to let them know we were monitoring the situation,” says Matthew.
CDEM Head of Strategy and Planning Craig Glover says Civil Defence agencies in New Zealand use information analysed by Geonet.
“Seismic information is collected by many organisations around the world and we often see a lot of raw data reported in the early stages of an emergency response.
“It’s the responsibility of local (regional in Auckland Council’s case) civil defence groups to manage their own responses so it’s important that we consider information from a reliable source, analysed against good modelling and local experience,” says Craig.
“However,” says Craig. “Tsunami activity anywhere along our coastline can cause strange currents and sea surges so marine warnings are important precautionary measures.”
Information from Geonet and advice from the Ministry of Civil Defence and Emergency Management lead to a decision by Auckland’s Director of Civil Defence not to evacuate.
“Evacuation can cause significant stress on people so we must ensure essential public safety is balanced with well-informed decision-making,” says Director John Dragicevich.
“We were confident that Auckland was not under threat and we were able to validate this with the Ministry within 20 minutes of the nation-wide east coast tsunami advisory being issued – that shows good collaboration with the national agency and a strong understanding of our own coastal environment,” he says.
Why did other places activate their sirens or evacuate?
Some neighbouring civil defence groups activated tsunami warning sirens and evacuation plans, based on advice from the Ministry for their geographic area. Craig says these councils will have taken many things into account when activating their systems.
“They might not have the tsunami modelling data that we do; they might have more low-lying areas vulnerable to inundation or they might be in remote locations where a precautionary approach is necessary as emergency services are a long way away,” he says.
“We were confident that there was no tsunami threat to Auckland’s east coast so no precautionary measures, other than our ongoing monitoring of the situation and advice to stay out of the water, were needed.”
The marine threat that applied to the Auckland region following this morning’s quake and tsunami threat was lifted just after 8am this morning.
This is a reminder that Auckland is vulnerable in an earthquake or tsunami and we should all have emergency plans in place.