Restless Earth Learning Objectives To understand the Earths

Restless Earth

Learning Objectives • To understand the Earth’s structure • To know about the plates that make up the surface of the Earth

How old is the Earth? The Earth is… 2 million years old 100 million years old 30 million years old 4600 million years old

The layers of the Earth

The layers of the Earth The core • The core is mainly made up of iron, mixed with a little nickel. • The temperature is 5500 o. C in the middle of the core • The outer core is liquid and is 2220 km thick • The inner core is solid and is 1260 km thick

The layers of the Earth The mantle • The mantle forms about half of the Earth and is between the core and the crust. • It is made of hot, slow –flowing, solid rock. • The mantle is denser than the crust. It has more magnesium and less aluminium and silicon than the crust. • It is 2900 km thick and the temperature ranges from 500 -900 o. C • Convection takes place in the mantle.

CONVECTION IN THE MANTLE • When convection takes place in the mantle, cooler rock sinks and warmer rock rises. • Convection is the movement of matter that results from differences in density caused by variations in temperature.

The layers of the Earth The crust • The crust is the layer you live on and the outermost solid layer. • It is a thin layer of rock around the Earth • There are two types of crust: • 1. Continental crust (where there is land) which is 30 km thick • 2. Oceanic crust (under the sea) which is 5 km thick

WHAT ARE THE EARTH’S PHYSICAL LAYERS? • Earth can also be divided into layers based on physical properties. The properties considered include whether the layer is solid or liquid, and how the layer moves or transmits waves. • The 5 physical layers are: lithosphere, asthenosphere, mesosphere, outer core, inner core • LITHOSPHERE : The outermost , rigid layer of the earth is the lithosphere. The lithosphere is made of two parts—the crust and the rigid, upper part of the mantle. The lithosphere is divided into two pieces called tectonic plates. • OUTER CORE: The outer core is the liquid layer of the earth’s core. It lies beneath the mantle and surrounds the inner core. • INNER CORE: The inner core is the solid, dense center of our planet that extends from the bottom of the outer core to the center of the earth, which is about 6, 380 km beneath the surface.

Plate tectonics The structure of the Earth is like an egg: The Core Mantle Earth’s Crust – which is made up of pieces called tectonic plates

Plate tectonics The Earth’s surface is made up of pieces called tectonic plates. Plates are slabs of the lithosphere – Earth’s crust and upper mantle

They move because they are dragged along by the powerful convection currents in the soft hot rock in the mantle. Plate Mantle

So what have we learnt? Let’s play…

Who Wants To Be A Millionaire? Geography Edition

Question 1

How many layers of the Earth are there? A B C D 1 2 3 4

£ 100

Question 2

Which of these is most like the Earth? A B C D Tennis ball Egg Apple Satsuma

£ 500

Question 4

Which is the hottest layer of the Earth? A B C D Mantle Crust Inner core Outer core

£ 1000

Question 5

What layer do we live on? A B C D Inner core Mantle Outer core Crust

Which layer do we live on? A B C D Inner core Mantle Outer core Crust

£ 10, 000

Question 6

What are tectonic plates? A Something we eat our dinner on B Pieces of the Earth’s crust C Something you stand on in baseball D The thing a car licence number is printed on

£ 100, 000

Question 7

What tectonic plate do we live on? A B C D Pacific Antartic Eurasian Nazca

What tectonic plate do we live on? A B C D Pacific Anarctic Eurasian Nazca

£ 1, 000

Wanted; man for hazardous journey. Low wages, intense heat & pressure, long months of darkness & constant risks. Return uncertain.

Your mission – Homework: Diary Entry of a journey to the centre of the Earth (about 1 side A 4) • It might be a mission impossible, but use • • your imagination. What would you see on your journey to the centre of the Earth? What would you take with you? How would you return? How would you deal with the heat & pressure? So, some ideas to help you…

References • Includes: HMH Georgia Science Textbook