Nicola Litchfield, Earthquake Geologist, GNS Science
"It's exciting to see if our results match others, or whether she’s come up with something entirely new that will change the big ideas”
Nicola is trying to figure out the timing and size of past large earthquakes along the East Coast of the North Island in order to better understand and forecast the future earthquake hazard for the east coast.
She works alongside a team of other paleoseismologist to search for prospective raised beach study sites from aerial photographs and maps (especially lidar these days) and then visit and survey them in the field. At selected sites they excavate trenches across the raised beaches (at right angles to the beach) to expose the raised beach and tsunami sediments, and to collect shells. Shells are radiocarbon dated at their lab in Wellington, and the ages analysed to determine the timing of past earthquakes and tsunamis. They then compare the results to those from other sites along the east coast, and to computer models of earthquake timing and size, and tsunami run-up. The records of what happened in the past provide information on what will happen in the future.
For Nicola, it’s really exciting uncovering something for the first time, and to then to figure out how this small piece of the puzzle fits in with the rest. For example, whenever she excavates a trench she never quite knows what she’s going to find beneath the ground surface, and therefore whether her ideas of how a landscape has formed are correct. She says it’s then exciting to see if her results match others, or whether she’s come up with something entirely new that will change the big ideas. Nicola’s work is forever ongoing so be on the look out for her research progress and findings.