Deep within the Earth it is so hot that some rocks slowly melt and become a thick flowing substance called magma. Since it is lighter than the solid rock around it, magma rises and collects in magma chambers. Eventually, some of the magma pushes through vents and fissures to the Earth’s surface.

Most are located around the Pacific Ocean in what is commonly called the Ring of Fire. A volcano is defined as an opening in the Earth’s crust through which lava, ash, and gases erupt.

Igneous rocks

Magma has the tendency to rise because it weighs less than surrounding hard rock (liquids are less dense than solids) and because of the pressure caused by extreme temperature. The pressure is reduced as magma rises toward the surface. Dissolved gases come out of solution and form bubbles.

More than 80 percent of the Earth’s surface–above and below sea level–is of volcanic origin.

about 2,900 kilometers

The lower mantle is the liquid inner layer of the earth from 400 to 1,800 miles below the surface. The lower mantle has temperatures over 7,000 degrees Fahrenheit and pressures up to 1.3 million times that of the surface near the outer core.

The Earth’s mantle, on which the crust is lying on, is not made of liquid magma. It is not even made of magma. The Earth’s mantle is mostly solid from the liquid outer core to the crust, but it can creep on the long-term, which surely strengthens the misconception of a liquid mantle.

Asthenosphere –The asthenosphere is made of very viscous, ductile, semi-solid material on which the lithosphere moves. It is a solid that can behave like a liquid, and it is about 440km thick.

Explanation: The difference between these two layers of the mantle comes from the predominant mineral phases in the rock. Both the upper and lower mantle consist primarily of silicate minerals. Asthenosphere: Most of the upper mantle is hot enough, above 1300°C, for its rock to undergo plastic flow.

As ancient ocean floors plunge over 1,000 km into the Earth’s deep interior, they cause hot rock in the lower mantle to flow much more dynamically than previously thought, finds a new study. …

mesosphere

about 640 km

Structure of the Earth

The Upper Mantle: Temperature and Depth The upper mantle begins just beneath the crust and ends at the lower mantle. The thickness of the upper mantle is between 200 and 250 miles. The entire mantle is about 1800 miles thick, which means the lower mantle makes up the bulk of this part of the Earth.

Humans have drilled over 12 kilometers (7.67 miles) in the Sakhalin-I. In terms of depth below the surface, the Kola Superdeep Borehole SG-3 retains the world record at 12,262 metres (40,230 ft) in 1989 and still is the deepest artificial point on Earth.

The lower mantle below the Asthenosphere is more rigid and less plastic. Below the Mantle is the outer core. The outer core is composed of a liquid….