Objectives

- describe different layers of the Earth and their composition

- explain how the structure of Earth is the cause of volcanoes and earthquakes

Felix Baumgartner

A lot of you might think this photo is of an astronaut in space. That is incorrect!

Felix Baumgartner's famous 2012 jump took place from the stratosphere, not from space. He was 24 miles above sea level (space begins 62 miles up!) and performed the highest skydive and fastest freefall ever recorded.

The 4 Spheres of the Earth

Lithosphere/Geosphere - made of rocks, the crust, and upper mantle

Hydrosphere - all the water on Earth

Biosphere - all life on Earth

Atmosphere - the layer of gases that surrounds Earth

The Crust

Crust - the outermost layer, the layer we live on, the most studied, 1% of the total volume of Earth, consists of continental crust and oceanic crust

Tectonic Plates

The crust is made up of tectonic plates - massive slabs of rock that move due to convection currents in the mantle.

There are 3 types of plate boundaries:

divergent boundaries - plates are moving away from each other

convergent boundaries - plates are coming together and one is being pushed down beneath the other

transform boundaries - plates slide past each other

The grinding of these plates can cause earthquakes.

The Mantle

Mantle - lies between the crust and core, makes up 84% of Earth's volume and 67% of its mass

Divided into upper mantle (part of the lithosphere) and the lower mantle.

As the plates move, molten material from the mantle pushes upward through cracks and forms a volcano.

The Core

Core - made of the inner core (solid) and outer core (liquid), the heaviest metals are found here, the hottest part of the planet.

Why is it hot? - primordial heat from Earth's formation, radioactive elements release heat, and radioactive decay

Generates the magnetosphere - protects Earth from dangerous radiation from space

The Atmosphere

Gravity keeps the atmosphere close to Earth's surface.

Critical component of what makes Earth habitable.

Importance - contains oxygen for living things, protects from harmful radiation, traps the heat of the sun

Great Job!

Today, you learned:

- different layers of the Earth and their composition

- how the structure of Earth is the cause of volcanoes and earthquakes