GEOLOGY

Detailed explanation-1: -Over 80 per cent of large earthquakes occur around the edges of the Pacific Ocean, an area known as the ‘Ring of Fire’; this where the Pacific plate is being subducted beneath the surrounding plates. The Ring of Fire is the most seismically and volcanically active zone in the world.

Detailed explanation-2: -Highest earthquake hazards in the USA are found on the west coast, the western mountain range, the midwest south of the Great Lakes, the southern coast of Alaska, and the big island of Hawaii.

Detailed explanation-3: -The Pacific Plate is thinner and denser, so it is being thrust underneath the North American plate. This subduction zone has generated many large, devastating earthquakes, including the second largest earthquake ever recorded: the magnitude 9.2 Good Friday earthquake in 1964.

Detailed explanation-4: -The earthquakes of California are caused by the movement of huge blocks of the earth’s crust-the Pacific and North American plates. The Pacific plate is moving northwest, scraping horizontally past North America at a rate of about 50 millimeters (2 inches) per year.

Detailed explanation-5: -More than 80% of earthquakes occur in an area known as the Pacific Ring of Fire, a 25, 000-mile horseshoe shape along the north side of the Pacific Ocean. The main reason for the difference, Ebel says, is that the California coast is right above the boundary of two of the tectonic plates that make up the Earth’s crust.