Overview

• The Science Advances study employed a 15-kilometre-long towed hydrophone array to capture the first detailed seismic images of the Queen Charlotte/Haida Gwaii plate boundary.
• Imaging shows the Pacific plate diving beneath the North American plate along a roughly 300-kilometre stretch off Haida Gwaii and southeast Alaska.
• Researchers describe the feature as an early-stage subduction zone capable of generating large thrust earthquakes and tsunamis, though its sustained evolution is uncertain.
• Co-author Michael Bostock says another megathrust earthquake similar to the 2012 magnitude-7.8 event is unlikely for at least a century due to slow convergence rates.
• The new geometric constraints are being incorporated into seismic and tsunami hazard models to guide updates to building codes and evacuation planning on B.C.’s north coast.