/News & Beyond/Award to unlock hidden record of past earthquakes
Jeff Lang is one of just 20 early-career researchers to be awarded an Aotearoa New Zealand Tāwhia te Mana Research Fellowship.
Worth $820,000 over four years, the fellowship will help Jeff develop a novel approach to identifying past earthquakes, using a natural record stored within caves.
“In young countries such as Aotearoa New Zealand, our knowledge of the long-term recurrence of large earthquakes is limited because our written records are short,” says Jeff. “This affects our ability to assess earthquake risk.”
In caves, stalagmites record changes in groundwater chemistry, often over tens of millennia. For his PhD at the University of Auckland, Jeff worked with a research team that hypothesised that when earthquakes fracture cave rocks this briefly raises magnesium in the groundwater above the caves. The stalagmites record that as a magnesium pulse.
“By analysing and dating stalagmites near major historic earthquakes we can test this hypothesis which, if true, could help to greatly extend our country’s seismic record,” he says.
Jeff will focus his research on caves in Hawkes Bay, which is on the Hikurangi Subduction Margin, Aotearoa New Zealand’s largest and least understood source of earthquake risk.
Collaborating with local kaitiaki, Jeff will analyse samples from selected caves to identify the magnesium signatures of historic earthquakes.
He will use this data to develop a tool for determining earthquake intensity from measured magnesium. It will be calibrated against the shaking intensity of known past earthquakes, based on mātauranga Māori and records from 1840 on.
The aim is to produce a continuous earthquake record for Hawkes Bay for the Holocene – the period since the last ice age.
Ultimately, the method Jeff develops in this research could be used to uncover the record of past earthquakes held in caves across Aotearoa New Zealand and the world.
Lincoln Agritech’s Environmental Group Manager Simon Pollock said the company was incredibly proud of Jeff’s achievement.
“His work will support New Zealand’s ability to forecast and plan for earthquakes and we know that this work will have impact not just in New Zealand but around the globe.”
