Answer:
The Cascadia Subduction Zone is where the Explorer, Juan de Fuca, and Gorda plates move towards the east and are being pushed below the much larger North American Plate at the continental divide.
Step-by-step explanation:
Although culturally, socially and to some extent geologically there is a wider region called the Cascadian bioregion that shares patterns of natural characteristics like watersheds and weather that extends from Northern California up to the southernmost points of Alaska and the Yukon territory, technically the Cascadia Subduction Zone describes the area from Northern Vancouver Island to Cape Mendocino in the north of California. It is 1000 km or 620 miles long and it is a region with a lot of seismic activity because it separates the Explorer, Juan de Fuca, Gorda, and North America plates. Tectonic processes affecting large cities in this area like Vancouver, British Columbia, and Portland, Oregon are accretion and deep earthquakes due to the subduction between the plates. Active volcanos are present in the Cascades like Mount Rainier and Mount Saint Helens.