Dr Ursula Cochran collecting microfossils at Okupe Lagoon on Kapiti Island. Photographer: Kate Clark
“We hope our research will enable us to forecast the next 'megathrust' earthquake.”
When Ursula was a child she liked thinking about the earth and started collecting rocks and fossils, but it wasn’t until she went to university that she got inspired to be a geologist. Now she is part of the earthquake geology team at GNS Science. They want to know where, how often and how big past earthquakes were.
Ursula along with the team at GNS Science are trying to find physical evidence of past large-great earthquakes or ‘megathrust’ earthquakes that have happened on the Hikurangi subduction zone. The Hikurangi subduction zone lies just off the East Coast where the Pacific plate is moving down under the Australian plate. This is New Zealand’s largest fault.
She takes cores of old sediments from coastal lagoons and studies the changes in microfossils back through time. She does this to find evidence for the land moving vertically and the tsunami inundation that happens in large earthquakes. Radiocarbon dating helps her work out how old the past events are.
No one knows when earthquakes will occur but scientists try to predict how often different sized earthquakes happen. This research is ongoing, however a summary report is due out in mid-2017.