Geological Processes Of The Earth Essay

Essay 50: Geological Processes in the Earth’s Interior The Earth is a terrestrial planet consisting of a crust, mantle, molten outer core, and solid inner core. The Earth’s crust is rich in silicon, aluminum, and other elements less massive than iron. Most of the Earth’s iron and heavier elements are located in the mantle and core. The crust extends about 40 miles below the continents but only 10 miles underneath the ocean basins. Strange as it may seem, the crust comprises only 1% of our planet’s mass; the mantle and core constitute the other 99%. To put it in perspective, if the Earth were the size of a peach, the crust would correspond to the skin of the peach. The fruit and pit correspond to the mantle and core, respectively. The mantle consists of semisolid igneous rock that gradually becomes entirely liquid closer to the core. Small amounts of mantle are ejected during volcanic eruptions, given that the roots of volcanoes often extend 100 miles or more below the Earth’s surface. The outer core is thought to be made up of molten iron, nickel, and other metals. The inner core is an extremely dense metallic ball. Even though the inner core is hotter than the outer core, it remains solid due to its high density as well as the immense pressure exerted on it

Heat circulating in the Earth’s mantle is believed to drive the movement of tectonic plates. Although the plates are moving at approximately one inch per year, this accounts for the rearrangement of Earth’s continents over vast spans of geologic time. At their boundaries, tectonic plates collide, spread apart, or move in parallel but opposite directions to each other. As a result of these movements, most earthquakes occur at tectonic plate boundaries. Seismic activity is a continuous phenomenon. Earthquakes strong enough to be felt, however, occur at intervals of months or