A group of New Zealand earthquake scientists are listening to the “hum of the Earth” while examining seismic hazards on the Paeroa Fault.

The team installed 147 small seismometers in a five-square-kilometre area south of Rotorua on the North Island to examine soundwaves and rumblings in analysing the fault’s structure and depth.

“If we know how deep the fault goes and on what angle, we can determine how big an area may rupture and what magnitude earthquakes it may trigger,” project lead Dr Brook Keats said.

“We listened to the hum of Earth, including the sounds of the waves crashing into the Bay of Plenty coast just over 50km away, and measured the seismic velocity, or how fast the sound travels to different locations and at different depths.”

The project, funded by the Natural Hazards Commission Toka Tu Ake, also incorporates contributions from the Maori iwi (tribe) Ngati Tahu – Ngati Whaoa.

The researchers says their project is among the first in New Zealand to use miniature, easy-to-install seismometers, which are “perfect for targeted studies like this one”. 

“In this case we went for quantity over quality and because we were able to install so many very quickly, we were able to overcome the quality issue by collecting so much data in just a month,” Natural Hazards Commission research head Dr Natalie Balfour said.

“This research will provide a greater awareness of how big, and how often, the Paeroa Fault will rupture and will support local iwi, councils, communities and lifelines to prepare for these risks and build resilience.”