Lava flow research shows Auckland’s water pipes and power cables are probably buried deep enough to survive a short volcanic eruption, but more work is needed to assess the impact of a larger event.

Experiments at the US Syracuse University Lava Project show one-metre-thick flows from molten basalt rock would barely affect the ground past a depth of 40 centimetres.

Auckland is built on a volcanic field of at least 53 small volcanoes, most of which have erupted once each for short periods. The most recent eruption was about 550 years ago.

University of Auckland research student Sophia Tsang, who conducted tests with Earthquake Commission funding, says she is using the initial results to begin estimating the impact on essential services under larger flows.

“If we get an eruption in Auckland, the lava flow could be a lot thicker and flow for longer than in my experiment,” she said. “The length of time the lava flow is active strongly controls how much heat is transferred into the ground below.”

The research will also examine where lava would flow in scenarios developed by the Determining Volcanic Risk in Auckland research program.

A future eruption would probably involve a new volcano being formed.