A new study published in Science Advances has revealed that the Juan de Fuca plate is fracturing into small pieces as it slides beneath North America, a process geologists from Louisiana State University and the Lamont-Doherty Earth Observatory describe as a “slow-motion train wreck.” Instead of sliding smoothly, the oceanic crust is tearing apart, significantly reshaping continents over the long term and potentially impacting volcanic and seismic activity in the Pacific Northwest.
Researchers found a 75-kilometer-long crack in the Cascadia subduction zone, a major fault spanning 1,000 kilometers from Vancouver Island, Canada, to northern California. At this point, the Juan de Fuca oceanic plate is forced under the continental North American plate. Lead author Brandon Shuck noted that stopping plate movement requires a massive collapse. The study shows that the Explorer plate and parts of the Juan de Fuca plate are undergoing “deviation,” causing the crust to fracture and sink unevenly in a process called plate tearing. This allows hot mantle material to rise into newly created spaces, increasing volcanic risks in the Cascade Range.
