The second layer of the Earth is the mantle, which is the thickest layer at a depth of 1,800 to 2,900 miles. It is composed of silicate rocks that are mostly solid but can flow slowly over long periods of time. The mantle is divided into two parts: the upper mantle and the lower mantle. The upper mantle is mostly solid and has a thickness of about 1,800 miles. It is composed of olivine, pyroxene, and other minerals. The lower mantle is much hotter and denser, with temperatures reaching up to 4,000°F and pressures reaching up to 1.3 million pounds per square inch. It is composed of peridotite, which is a dense rock made of magnesium, iron, and silicon.
The mantle contains most of the Earth’s mass and is the source of the Earth’s internal heat. It is made up of two main convective systems. The first is called the mantle plume and is a large upwelling of hot, buoyant material from deep within the mantle. This material rises to the surface and forms volcanoes. The second is called the convection cell and is a large circulating system of material in the mantle. It is responsible for the movement of the plates making up the Earth’s surface.
The mantle is also the source of most of the Earth’s volcanism and earthquakes. The mantle is divided into two main regions: the lithosphere and the asthenosphere. The lithosphere is the cold, rigid layer of the upper mantle and is the source of tectonic plates. The asthenosphere is the hot, ductile layer of the lower mantle and is the source of volcanism and earthquakes.
The mantle is an important part of the Earth’s structure and is responsible for much of the Earth’s internal heat and movement. It is composed of silicate rocks that are mostly solid but can flow slowly over long periods of time. It is divided into two parts: the upper mantle and the lower mantle. The lithosphere and asthenosphere are two main regions of the mantle and are responsible for the movement of tectonic plates and volcanism. The mantle is an important part of the Earth’s structure and is the source of most of the Earth’s internal heat and movement.