A group of researchers from universities in the United States and Canada have mapped the area where three tectonic plates meet along the west coast of North America, around Vancouver Island. The process allowed us to understand how plates interact and will be the basis for studies on earthquakes and geological processes.
In practice, it was the first time that a geological study managed to detail this dynamic. The group of 20 scientists carried out a type of scanning of the ocean floor in a range of 75 km, using specialized sonar. The fault in the researched area extends across the entire Pacific coast of North America, running from Canada to California, to the south of the United States.
Among the conclusions of the study, published in articles in June and September 2024, are that one of the plates is fragmenting, a process that reduces its activity, but that the region is still active and is related to the activity of volcanoes and the incidence of high-intensity earthquakes. Scientists have classified this interaction space as a type of “megasystem” or subduction zone, where one plate overlaps the others. This type of system involves a huge amount of energy and is very difficult to stop, leading to large cracks, and this is the type of interaction that remains unheard of.
The system, made up of the Juan de Fuca and Explorer plates, which slide under the North American plate, is developing slowly and is creating “chunks” on the ocean floor, with the fragmentation of the Juan de Fuca plate. The data was collected during the 2021 Cascadia Seismic Imaging Experiment (CASIE21), funded by the National Science Foundation of the United States.
