where does most seismic activity occur on earth
Earthquake Most of the world's earthquakes (90%, and 81% of the largest) take place in the 40,000Â km long, horseshoe-shaped zone called the circum-Pacific seismic belt, known as the Pacific Ring of Fire, which for the most part bounds the Pacific Plate.[39][40] Massive earthquakes tend to occur along other plate boundaries, too, such as along the Himalayan Mountains.[41]
Crust (geology) The crust of the Earth is composed of a great variety of igneous, metamorphic, and sedimentary rocks. The crust is underlain by the mantle. The upper part of the mantle is composed mostly of peridotite, a rock denser than rocks common in the overlying crust. The boundary between the crust and mantle is conventionally placed at the Mohorovičić discontinuity, a boundary defined by a contrast in seismic velocity. The crust occupies less than 1% of Earth's volume.[1]