Geomagnetic storms can corrode NZ pipes, Northland vulnerable to damage, physicists warn

Geomagnetic storms can cause corrosion in New Zealand's pipelines, with areas, including Northland, more vulnerable to damage, according to physicists at Victoria University of Wellington and the University of Otago.

Victoria's Dr Malcolm Ingham and Otago's Professor Craig Rodger are midway through a Government-funded research project that focuses on reducing the damage to electrical networks from currents induced in the ground by large geomagnetic storms.

Professor Rodger says as people become more technologically dependent, a solar eruption from the sun can cause changes in the Earth's magnetic field - a magnetic storm - affecting power and satellites, along with corrosion in pipelines.

"If you've got a hole in a pipeline cladding, variations in the geomagnetic field will cause corrosion over time, leading to containment failure and leakage."

Areas perpendicular to coastlines, such as Auckland and Northland, can have large electrical currents in the ground, Dr Ingham says.

Last month's damaged fuel pipeline in Northland is probably an example of how pipelines can be affected by geomagnetic storms if the pipe cladding is damaged, he said.

"If a digger has previously, even years ago, scraped the coating of that pipeline, each geomagnetic storm since could have caused a little bit more corrosion and eventually it would give. That event also happened a few days after there was a big geomagnetic storm.

"To me, the effects of [these] storms is something that should be considered when investigating the cause of the incident."

More research needs to be done into how to mitigate corrosion to pipelines due to changes in the geomagnetic field, the researchers say.

Repairs of the Marsden Point pipeline are well underway.
Repairs of the Marsden Point pipeline are well underway. Source: SUPPLIED