Agenda 2/24Agenda 2/24

• Warm-Up: What is below your feet here on campus at McEachern?

• Warm-Up Check

• Pass back/discuss Unit 1 Test

• Notes: Layers of the Earth

• Activity: Earth Layers Analogy

The Earth’s LayersThe Earth’s Layers

Objective:Objective:

• The learner will be able to identify characteristics of the Earth's layers.

The Earth is divided into three The Earth is divided into three layerslayers..

CrustCrust• The crust is the layer that

you live on so it is the most widely studied and understood.

• It is also known as the lithosphere.

CrustCrust• The crust is made of the

lightest matter and the core consists of heavy metals

CrustCrust• The Earth's Crust is like the

skin of an apple. It is very thin in comparison to the other three layers.

CrustCrust• The crust of the Earth is

broken into many pieces called plates. The plates move along the soft mantle which is the layer located located below the crust.

CrustCrust• The plates move along smoothly

but sometimes they get stuck and pressure builds up.

CrustCrust

The pressure builds and causes an Earthquake as rocks break and crack.

                                                             

                    

San Francisco City Hall after the 1906 Earthquake. (from Steinbrugge Collection of the UC Berkeley Earthquake Engineering Research Center)

MantleMantle• The mantle is the largest layer of the Earth. • The top layer of the mantle is known as the

asthenosphere.• Below that are the upper and lower

mesosphere.• It is made of hot, dense rock. The rock in the

mantle flows like asphalt because of the temperature differences found in the mantle.

MantleMantle• The movement

of the mantle create the movement of the Earth’s plates.

CoreCore• The core of the Earth is

much like a ball of very hot metals. The inner core is surrounded by a fluid iron outer core.

CoreCore