Updated

Researchers studying a subduction zone off Vancouver Island have captured evidence of it tearing itself apart piece by piece, challenging assumptions that these massive tectonic systems die all at once. The discovery offers new insight into the Cascadia region's geologic history and future earthquake risk. The findings could help explain ancient plate fragments and volcanic activity in the region, and may inform future assessments of how hidden tectonic breaks beneath the Pacific Northwest could influence seismic hazards.