The Layers of the Earth! By Jana Smalley- Bozman Intermediate, CISD, January

Earth Layers The Earth is divided into four main layers: *Inner Core *Outer Core *Mantle *Crust Have students fill out small squares with the information (Composition, Thickness and State of Matter) for each of the main layers of the Earth.

The Crust and Lithosphere the outer shell of Earth that makes up the continents and the land beneath the oceans—it's the thinnest layer! Composition: * --mostly Oxygen (O) & Silicon (Si) *solid * Thickness or Depth: km 5 km under the oceans (oceanic crust) and km under the continents (continental crust) * Temperature: from 30ºC to 1500ºC * The Earth’s crust is like the skin of an apple. It is very thin compared to the other three layers. *The crust makes up only 1% of the mass of the Earth.

The Lithospheric Plates The Earth's crust is broken into many pieces called plates. These plates are found in the Lithosphere and "float" on the soft, semi-rigid Asthenosphere.

The Mantle & Asthenosphere The mantle is the thickest layer and is found below the crust and has 3 different areas within it. Composition: Upper Mantle=lower Lithosphere- which is hard and rigid and contains the plates of the Earth. Middle Mantle=Asthenosphere – has properties of both solids and liquids and is thought to be constantly moving in CONVECTION CURRENTS which cause the lithosphere & plates above to move The Lower Mantle is semi-rigid or partly hard. Made of mostly Iron (Fe) and Magnesium (Mg) Thickness or Depth: 2900 km Temperature: º C

Outer Core the outer part of the core is liquid metal and very hot! It spins around the solid inner core and causes the Earth's magnetism. Composition: liquid--it is like a ball of very hot, molten metals! made up of liquid Iron (Fe) and Nickel (Ni) and is very dense- but not as dense as the inner core Thickness or Depth: 2200 km Temperature: 4000ºC to 5000º C explanation of why the Earth has a magnetic field: Our planet’s magnetic field is believed to be generated deep down in the Earth’s core. Nobody has ever taken the mythical journey to the centre of the Earth, but by studying the way shockwaves from earthquakes travel through the planet, physicists have been able to work out its likely structure. Right at the heart of the Earth is a solid inner core, two thirds of the size of the Moon and composed primarily of iron. At a hellish 5,700°C, this iron is as hot as the Sun’s surface, but the crushing pressure caused by gravity prevents it from becoming liquid. Surrounding this is the outer core, a 2,000 km thick layer of iron, nickel, and small quantities of other metals. Lower pressure than the inner core means the metal here is fluid. Differences in temperature, pressure and composition within the outer core cause convection currents in the molten metal as cool, dense matter sinks whilst warm, less dense matter rises. The Coriolis force, resulting from the Earth’s spin, also causes swirling whirlpools. This flow of liquid iron generates electric currents, which in turn produce magnetic fields. Charged metals passing through these fields go on to create electric currents of their own, and so the cycle continues. This self-sustaining loop is known as the geodynamo. The spiralling caused by the Coriolis force means that separate magnetic fields created are roughly aligned in the same direction, their combined effect adding up to produce one vast magnetic field engulfing the planet.

Inner Core deepest layer of Earth- solid Iron- SUPER HOT!!! COMPOSITION: Solid IRON (Fe) Super DENSE VERY HOT!! Thickness or Depth: 1250 km Temperature: 6000º C

MODELS represent scientific things which we cannot really show you-- because they are either far to BIG (like the Solar System) or far to Small (like a cell)-- or simply too Dangerous We will create several MODELS of the EARTH THIS WEEK! The materials we will use include: Paper Play-doh Fruits and Vegetables Begin thinking of all of the interesting and creative ways you could model the Earth's Layers...

Models Engineers, Architects, and Geologists use models to SCALE for their models and blueprints A SCALE Model- is a concept that means the model - --is accurate in a size comparison to the real object For example: a map could be drawn to scale using 1 cm = 100,000 kilometers In order to create a scaled model of the Earth-- we could use a scale of 1 cm = 500 km

Review- Give students the Mini Layers of the Earth page to complete:) FORMATIVE ASSESSMENT Follow the following link to complete foldable: LLLL aaaa yyyy eeee rrrr ssss o o o o ffff t t t t hhhh eeee E E E E aaaa rrrr tttt hhhh! 1) What are the four layers of the Earth? 2) The Earth’s crust is very ______? 3) The mantle is the largest layer of the Earth? True or False 4) Is the Outer Core a liquid or a solid?

Answers! 1) Crust, Mantle, Outer Core, Inner Core 2) Thin 3) True 4) Liquid