Seismic imaging reveals a strain-partitioned sliver and nascent megathrust at an incipient subduction zone in the northeast Pacific.

ABSTRACT: The Queen Charlotte plate boundary (QCPB), a transform separating the Pacific and North American plates, accommodates ~55 millimeters per year of motion, is a source of large earthquakes in the northeast Pacific, and may be a modern site of subduction initiation. The southern QCPB experiences oblique convergence, showcased by the 1949 magnitude (M) 8.1 strike-slip earthquake and the 2012 M7.8 tsunamigenic thrust earthquake, both offshore Haida Gwaii, British Columbia. We present seismic reflection images of the southern QCPB, which constrain the crustal structure in unprecedented detail. The Queen Charlotte Terrace is underthrust by oceanic crust topped by a throughgoing, low-angle plate-boundary thrust, which ruptured in the 2012 earthquake. The Queen Charlotte Terrace is an

SUBMITTER: Brandl CC 

PROVIDER: S-EPMC12273783 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature