EARTHS LAYERS EARTHS LAYERS Earths layers core mantle

EARTH’S LAYERS

EARTH’S LAYERS Earth’s layers core, mantle, crust

CORE Core center of earth; divided into outer core and inner core

INNER CORE Inner core solid and innermost layer ● made of solid iron and nickel ● temperatures up to 5, 000 C ● greatest amount of pressure of all layers ● believed to be responsible for earth’s magnetic field ● depth = 5150 km

OUTER CORE Outer core surrounds inner core ● 2 nd layer of the core ● depth = 2, 900 km ● thickness = 2, 250 km ● made of liquid iron and nickel ● temperatures = 2, 200 C in upper part to almost 5, 000 C near inner core

MANTLE Mantle second layer of the earth ● thickest of all layers ● temperature and pressure increase with depth; 870 C in upper mantle to 2200 C in lower mantle Plasticity property which allows solid rock to flow slowly; mantle has this property

CRUST Crust thin, outermost layer of earth (3 rd layer) ● all life exists on or within a few hundred meters above crust ● made of 3 types of solid rock: igneous rock, metamorphic rock, sedimentary rock 2 types continental crust – under continents (thicker) oceanic crust – under oceans (thinner)

BY TEMPERATURE COOLEST TO HOTTEST: CRUST → MANTLE → OUTER CORE → INNER CORE

BY THICKNESS THINNEST TO THICKEST: CRUST → INNER CORE → OUTER CORE → MANTLE

LITHOSPHERE Lithosphere: solid, topmost part of the earth; 50 – 100 km thick and broken up into large sections called lithospheric plates; there at least 7 major plates

ASTHENOSPHERE Asthenosphere: the layer directly beneath the lithosphere; the upper edge of the mantle; Made of hot molten material, which has the property of plasticity; ● lithospheric plates move on the hot molten material that forms the asthenosphere

MOHO Moho boundary between earth’s crust and underlying mantle

Layers of the Earth Quiz 1. List the 4 main layers that make up the earth. 2. Explain how scientists get information about the different layers of the earth if they can’t see them. 3. How are the inner core and outer core different? 4. Describe the most unusual physical property of the mantle. 5. What are the two distinct parts of the Earth’s crust? Explain the differences between these two parts. 6. Order the layers of the Earth from the thickest to the thinnest, include the name of the layer and its thickness.