An Introduction to Ch 11&12 LAYERS OF THE EARTH!

Regions of the Earth The Earth is made up predominantly of two major regions: A predominantly molten, central core A mostly solid outer mantle and crust

Hydrosphere and Crust (0-35km) The crust is the top, solid surface layer of the Earth

Quick Fact: The crust and the upper mantle are part of what we call the Lithosphere! (the solid portion of the Earth) The Aesthenosphere is the ductile – semi- liquid/solid part of the Earth located just below the Lithosphere. The Aesthenosphere includes the upper mantle.

Hydrosphere and Crust (0-35km) The Hydrosphere contains the bodies of water at or near the surface, including: Frozen surface water Liquid surface water Ground water Water vapour All told the Earth’s water totals an estimated 336 million miles (~540 million kilometers), 97% of which is contained in the oceans

Let’s Journey to The Center of the Earth!

The Mantle: (35-2900km) The mantle is the semi- solid layer directly below the crust. It can itself be broken into three distinct parts: The Upper Mantle (35- 670 km) The Transition Zone (300- 700km) The Lower Mantle (670- 2900km)

The Upper Mantle: (35- 670 km) The contents of the upper mantle are not as well defined as the crust and other layers. It includes xenoliths, rocks that were shot upward by explosive eruptions (some of which contain diamonds)! Processes that take place in the upper mantle have significant impact at the crust, in the form of: Volcanic eruptions Earthquakes The introduction of some ores

The Transition Zone: (300-700km) About 1/5th of the way through the mantle, increases in pressure and temperature turn many minerals into tightly packed crystals. This area is known as the transition zone because it separates the lower mantle from the upper mantle…

The Lower Mantle: (670-2900km) The lower mantle comprises nearly 50 percent of the Earth’s Interior. Rather than staying stagnant, the lower mantle convects slowly creating superplumes, large rising jets of partially molten rock.

The Outer Core: (2900-5200km) The outer core consists of liquid metal that flows turbulently . This creates a dynamo which creates the Earth’s main geomagnetic field on the Earth’s surface. The outer and inner cores generate so much heat, about 4000 to 5000 Kelvin, which contributes about one-fifth of the Earth’s internal heat which ultimately flows to the surface.

The Inner Core: (5200-6371km) While most of the core is liquid, the inner core is solid. It is believed to be metallic iron although no studies have ever been performed on the core.

Summary: