The circum-Pacific volcanic zone is a volcanic zone surrounding the Pacific Ocean. It formed as the Pacific Plate subducted under continental and oceanic plates, pushing volcanic islands and clusters up around the circumference. As subduction occurs, this zone experiences both volcanic activity and seismic activity. It began forming in the Mesozoic era as plates converged. This zone includes volcanic areas like Japan, Indonesia, the Philippines, the Aleutian Islands, the Andes, and the Rockies. Due to ongoing subduction, it experiences frequent earthquakes and has many more active volcanoes than the Alpine-Himalayan belt.