Although Hawke's Bay escaped unscathed from the earthquake which struck just after midnight on Sunday, and was felt around the country, it has provided a number of learnings.

People around the region were woken by the rolling quake, which seemed to last over a minute early Monday morning. Although it was initially measured as having a magnitude of 6.6, this has been revised to 7.8.

As a tsunami warning went out residents fled their homes in the middle of the night seeking higher ground, spending hours in elevated areas, or camping out at designated safety spots.

Although there has been criticism levelled at the mixed messages on the response to the earthquake, Hawke's Bay Civil Defence Emergency Management Group controller Ian Macdonald was pleased with the way it was handled.

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"We correctly determined that it wasn't a direct threat to Hawke's Bay, and we correctly evacuated those people who could have potentially been affected. At the end of the day it's about public safety so that was achieved in this particular case.

"We've still got some work to do, it's not perfect, but that's fine," he said.

This has been reiterated by the mayors of Hastings and Napier, who say based on Sunday's response they have confidence the region is prepared for such an emergency.

Hastings mayor Lawrence Yule had been woken by the quake.

He said even though it had taken a while to work out the scale of the tsunami threat, and what action to take, there had been a good response from both Civil Defence, and the public.

"The problem is most people need to realise when an earthquake is long, and strong like that ... people need to make calls. If it's long and strong, get gone," he said.

Although Napier mayor Bill Dalton thought the response had been well handled, there were "big learnings" from the emergency.

He had been in Australia when the quake hit, but had been filled in the next day.
He stressed the public needed to make their own calls when an earthquake struck, reminding them "if it's long and strong, get gone".

In response to criticism that no sirens were sounded, he said there was "absolute proof around the world that sirens are a really bad thing".

If a tsunami had been coming from a short distance and the sirens sounded, Mr Dalton said there would have been panic in the community, and "people would have still been mucking around trying to figure out what to do next".

Complaints about the lack of sirens were among other criticism of the response to the earthquake.

However, Mr Macdonald said while in hindsight it was easy to say there were actions which could been taken following the quake, "but based on the information we had at that time I think we made the right decisions. I wouldn't go back and change any decisions".

"Obviously we know a little bit more now but knowing what I knew then, I'd make the same decisions."

On Monday morning he and the Hawke's Bay Civil Defence Emergency Management Group (CDEM) sprang into action after the quake hit, spending the following hours activating the emergency centre, analysing data, communicating with the public, and making plans.

As the quake was initially measured as a 6.6, and from an inland source, a national advisory was issued around 40 minutes after it hit stating there was no threat of a tsunami to New Zealand.

This was relayed to the Hawke's Bay public on the group's social media.

Around 20 minutes later it was advised there were was a potential threat to southern coastal areas. Finally, an hour and a half after the quake, the team was informed there was a threat to the east coast of the North Island.

Without any information on wave heights there was no telling how severe this could be, Mr Macdonald said, before modelling from a team at Hawke's Bay Regional Council found there was not expected to be "significant inundation" from as a result of the earthquake.

"That was about the time we decided that we only needed to evacuate certain properties that are in what we call red zones and there's not many of those thankfully," he said.

They lie along coastal areas from Mahia to Central Hawke's Bay.

Residents in the red zone at Westshore in Napier were woken just after 2am, with Napier City Council staff knocking on the doors of individual properties expected to be affected.

By 3am, other evacuations were under way in Te Awanga, and Waimarama.

"It was very well co-ordinated on the ground," Mr Macdonald said.

"[Door knocking] was done by the police and fires and Civil Defence officers and it happened really quickly. That was all happening within the first couple of hours after the earthquake so from that perspective I think it went well."

After being roused from their beds residents spent the night sheltered in Civil Defence centres - such as the 300 who gathered at Haumoana school hall - or camped out in elevated areas.

Just before 6am, the tsunami warning was downgraded to a beach and marine threat.
Although people were able to return to their homes, Civil Defence warned the public to stay away from coastal areas.

It now appears there was no real threat to Hawke's Bay - Mr Macdonald said a 0.2m surge was measured at the Napier Port buoy which "could have been a wave".

However, the public have voiced criticism about the mixed messages of a tsunami warning, and the time it took to relay information to the public.

Some have also raised concern that stingers - public alerting systems - were used during the evacuations, yet public sirens were not.

The team have explained sirens were not used as a minority of households needed to evacuate. If the sirens had sounded in the early hours of Monday morning, it would have caused a mass evacuation across Napier and Hastings, potentially endangering lives.

Although Mr Macdonald has acknowledged there was confusion, he said no plan survives when emergencies happen.

"We had a lot of different information coming in over an hour to two hour period In the middle of the night. We had to analyse that information, come up with a plan, and also communicate the messaging to the public across a wide range of mediums.

"So that is not going to happen in one hour, it just can't happen."

When earthquakes occur, especially in a coastal region at risk of a tsunami, time is of the essence.

Mr Macdonald was applauding those who had made the decision to evacuate, without waiting for a warning from Civil Defence.

A number of people across Hawke's Bay self evacuated early Monday morning, fleeing their homes to higher ground - even if they were not in red zones.

When emergency services arrived in areas like Ocean Beach, and Haumoana, they found a number of residents had already gone.

"I think we were pleased and pleasantly surprised by the number of people who self-evacuated," Mr Macdonald, adding they had done a lot of work around community education so residents knew what to do.

In the past year, they had begun working with communities to develop their own plans on what actions to take in such an emergency.

"People knew that if the earthquake was long, if it was one that triggered for them to self-evacuate they knew where to go," he said.

"Sirens aren't going to give you a warning of a local tsunami ... so people really need to make a decision themselves."

Based on Monday's event, an area of response Mr Macdonald felt they did need to work on was around the CDEM webpage, and social media. It was very difficult to manage the various platforms at the same time while different information streamed in, so he felt this was an area where resources needed to be increased.

The event was also a good test of how prepared the community was for an event, and how they could improve.

Mr Macdonald stressed people "need to understand the risks they face and be prepared to do something about it".

The event had revealed there seemed to be a lot of reliance on CDEM being able to alert the public "in minutes", if a tsunami was going to hit.

"There's no system in the world that allows you to do that," Mr Macdonald said. "People need to take caution, especially if they live in a coastal area."

He cited the possibility of a rupture off the Hikurangi trench, east of Hawke's Bay.

"The first thing is that we would have a huge earthquake. Things will be falling off the walls, buildings will be damaged. That sort of earthquake, if it generates a tsunami, it will be here in about 20 minutes.

"So waiting around for sirens to go off, people are just going to become statistics. They really need to make a decision within the first minute or so," he said. "You can't muck around, the time you use to wait for a siren is time wasted.

"It might happen tomorrow, it might not happen in our lifetime but it will happen one day, so we've just got to be prepared for it."

- The Hawke's Bay Civil Defence Emergency Management Group have had two tsunami warning signs stolen from Haumoana and Waimarama. They would like these returned to Hawke's Bay Regional Council.