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Fracking study offers 'some reassurance' to NZ - expert

Published: 8:39AM Wednesday April 18, 2012 Source: ONE News

A UK study into hydraulic fracturing offers New Zealand "some reassurance" the process causes only very small, normal-range earthquakes, a GNS scientist says.

Much of the controversy surrounding 'fracking' has been fuelled by claims that the exploration technique causes earthquakes.

Fracking involves injecting a high-pressure mix of water, sand and chemicals into the ground to extract gas or petroleum.

Head of Petroleum Geoscience at GNS Science, Rosemary Quinn, told TV ONE's Breakfast the study conducted on the use of fracking in the English town of Blackpool last year found it caused only "very small earthquakes" up to 2.3 magnitude.

"We get about 150,000 earthquakes in New Zealand every year that are magnitude 2.3 and above, so that's about 50 a day and most people just don't feel them. That level of seismicity in New Zealand is normal."

Anything being induced by fracking, which is being reported in the literature, is causing no different activity than what happens naturally in New Zealand, Quinn said.

The report states that in many cases the earthquakes were going to happen anyway and the fracking merely brought them on sooner.

"If a fault were about to fail, it's a matter of timing and hydraulic fracturing has just accelerated that process slightly," Quinn told Breakfast.

"I think we can take this as some reassurance, and this is only the second published example of earthquakes being caused by hydraulic fracturing."

With regard to claims that fracking can lead to water contamination, Quinn said she is not sure we need more investigation.

But she said we need baseline monitoring of the aqua fizz before any well-drilling or hydraulic fracturing is carried out.

"And we need to be very sure that the wells are well-designed and well cased," she said.