Q&A: How can the Chignik, Alaska, earthquake help predict future risk?

Earthquakes are caused by the movement of the tectonic plates that make up Earth's crust. Off the coast of Alaska, the Pacific plate thrusts underneath the North American plate creating enormous pressure at the Alaska-Aleutian fault. Between 2020 and 2021, the two plates slipped along this fault, producing a series of earthquakes, including the Chignik, Alaska, earthquake on July 29, 2021, which registered an 8.2 in magnitude—the largest earthquake within U.S. territory in 58 years.