Set off the northern coast of Vancouver Island, a deep-sea endeavor is underway targeting one of the most earthquake-prone territories in North America. For 17 days, the on-board crew embarked on a groundbreaking project aimed to enhance future planning and predictions for earthquakes and tsunamis.
This five-year enterprise is designed to delve into the seismic hazards present across the Canadian pacific, especially within the offshore segments, as articulated by the lead scientist of the expedition, Andrew Schaeffer. A notable achievement of this mission is its distinction as the largest ever deployment of broadband ocean bottom seismometers within Canadian waters.
Orchestrated by the University of British Columbia, the initiative involves a slew of esteemed partners including the Geological Survey of Canada, the University of Victoria, and Dalhousie University.
A total of 28 cutting-edge instruments, known as ocean bottom seismometers, have been deployed to the unchartered ocean floor sandwiched between Haida Gwaii and northern Vancouver Island, in an area known as the Revere-Dellwood Fault. This region has never previously housed underwater seismic equipment, adding an extra layer of intrigue to the investigation.
Equipping the area with these devices allows scientists access to a comprehensive catalogue of minor seismic activity. This detailed log aids in foreseeing and modeling potential major earthquakes.
The invaluable information sourced from this scientific endeavor will serve as a meaningful contribution to the Canadian Seismic Hazard Model. This model is crucial in informing architectural decisions and shaping national building codes.
John Cassidy, a seasoned earthquake seismologist with the Geological Survey of Canada, notes that it will deliver the most insightful images and data about structure and seismic incidents in the area. He opines that understanding the frequency and intensity of ground shaking proves crucial for engineers when designing structures ranging from bridges, buildings to hospitals.
The management of the hardware that makes this scientific endeavor possible is in the trusted hands of Dalhousie University’s National Facility for Seismological Investigation (NFSI). The organization houses a pool of 120 such instruments used by various universities and government departments for sundry investigations.
These tools can autonomously record seismic data for approximately 18 months. At the end of the cycle, the instruments are instructed to ascend to the surface with an acoustic signal, where they are collected, data downloaded and recharged, shares NFSI manager Graeme Cairns.
Introducing these offshore instruments enhances the expanse and density of the on-land seismic network to offer fuller coverage. As per the planned trajectory of the project, the ocean-bottom seismometers will keep vigil over the area a year’s span before they’re reassigned elsewhere.
