Seismologist gives verdict on whether BoP quakes are building to something bigger after more than 600 quakes

After more than 600 earthquakes rattled Kawerau at the weekend a seismologist says it's too early to say if further quakes or even larger earthquakes could occur. 

In the early hours of Saturday morning, a swarm of earthquakes struck Kawerau - with eight of the 600 quakes being over magnitude 4. 

GNS Science duty seismologist John Ristau told AM earthquake swarms can last for days, weeks or even months. 

Ristau said the sequence of earthquakes appears to be tapering off but "we can't say at the moment when they will stop".

"We [haven't] had a magnitude four now for about the last 24 hours, so kind of hopeful that maybe it's starting to taper off, but we will just have to wait and see what will happen."

Asked if the swarm of quakes could lead to a bigger event, he painted a picture of the most likely scenario. 

"We can't say for certain that there won't be something bigger on the horizon," Ristau said. 

"It is going to do what it is doing at the moment, and you're going to start having the larger earthquakes less frequently, and in general in time the earthquake will happen less and less frequently until it eventually tapers off, dies off back to where it was before," said Ristau. 

Ristau told AM GNS Science suspects the quakes are not likely linked to any type of volcanic activity. 

"It's most likely that there are not any fluids involved in these earthquakes."

It was a sleepless Saturday night for those in the township of Kawerau. Former Mayor, now local councillor, Malcolm Campbell told AM he shot "out of bed like a rocket" and ran "around the house trying to save everything".

"Pretty intense on the Saturday night I must say."

Watch the full interview above.