Cascadia subduction zone shows deep tectonic fracturing

Geologists have discovered deep tectonic fracturing within the Cascadia subduction zone off the coast of Canada. Using the Cascadia Imaging Experiment (CASIE), researchers identified a 75-kilometer-long structure indicating that a section of the Earth's crust is fragmenting due to mantle forces acting on recent oceanic material.

Lead researcher Brandon Shuck of Louisiana State University noted that the process is not an abrupt surface collapse but rather a gradual fragmentation, comparing it to a train slowly derailing. The study, published in Science Advances, highlights how the interaction between the Juan de Fuca and Explorer plates with the North American plate creates complex internal dynamics that have historically triggered powerful earthquakes.