Where in the United States are earthquakes most likely to occur?

• A. East Coast
• B. Midwest
• C. West Coast
• D. Alaska

Answer: (C)

Earthquakes happen where rocks are being stressed along plate boundaries, and the most frequent activity occurs where tectonic plates interact. The West Coast sits directly on the boundary between the Pacific Plate and the North American Plate, including the San Andreas transform boundary and the Cascadia subduction zone. This makes the region prone to frequent and sometimes large earthquakes as the plates grind past each other or as one plunges beneath the other. In contrast, the East Coast and Midwest lie far from active margins, with older, thicker crust that doesn’t accumulate and release stress as often, so earthquakes are much rarer and usually smaller. Alaska does experience many earthquakes too, but the question’s framing and typical teaching focus point to the West Coast as the best example of an area in the United States with high earthquake potential due to its direct proximity to major plate-boundary motion.