EARTH’S INTERIORSC. 7.E.6.1

How do Geologist’s learn about Earth’s interior?

• •Evidence from rock samples Holes on Earth down to 12.3 km into itVolcanoes blast rocks from up to 100 km into Earth

• •Evidence from Seismic Waves – They reveal patterns where material changes (cliffs, mountains, submarine volcanoes, etc.)

Geologists at work: Examples

What are the features of Earth’s Crust, Mantle, and Core?• Every 40 meters – 1 Celsius Degree• Because of the weight of the rock above, pressure increases inside Earth. • The high temperatures inside earth are the result of the pressure and the

release of energy from radioactive substances and also from heat left from the formation of Earth approximately 4.6 billion of years ago.

The Crust- solid rockincludes dry land and ocean floorMain elements are: Oxygen and Silicon ( Silicate)5-40 km thick in most placesthickest under highest mountains – 80 km thickthinnest beneath the ocean

Oceanic Crust & Continental Crust• Oceanic Crust – Composed of Basalt• Continental Crust- It varies but most of its composition is

Granite. • ( p 101- Earth Crust Composition)

BASALT

GRANITE

Summarize: • Activity:• 1. Answer using complete sentences - What is the

relationship between temperature and depth inside Earth? Is this relationship the same for pressure? Why do you think this happens?

• 2. In a paragraph, compare and contrast the oceanic crust with the continental crust. In your writing be sure to consider the composition and thickness of both types of crust.

The Mantle • About 40 km beneath the Crust• Layer of hot rock• 3000 km thick• Three layers

• Lithosphere • Brittle, like the rock of the crust• Approximately 100 km thick

• Asthenosphere Less rigid and can bend like the metal of a spoon Under it there is a transition zone just on top of the Mesosphere

• Mesosphere• Stiff due to the increased pressure• It includes the lower Mantle

The Core• Made principally of Iron and Nickel• It also contains Oxygen, Sulfur and Silicon• Total Radius 3480 km • Two Parts

• Outer Core• Dense Liquid Part ( Molten Metal)• 2258 km thick

• Inner Core• Dense solid Ball under a lot of pressure• 1222 km thick

Summary• Draw the following chart on your notebook and complete

with the characteristics