Layers of the Earth Lets Take a Journey

Layers of the Earth

Let’s Take a Journey to the Center of the Earth • There are three main layers of Earth 1. The CRUST 2. The MANTLE 3. The CORE – All three layers differ in size, composition, temperature, pressure & density

Temperature • As you travel to the center of the Earth the temperature gets warmer • For every 40 meters you descend the temperature increases 1 degree Celsius

Pressure • PRESSURE – results when a force is pressing on an area • Pressure increases as you go deeper into the Earth

The Crust • CRUST – layer of rock that forms Earth’s outer skin – Includes both dry land the ocean floor – Also the soil and water that covers earth’s surface – Thin layer – Thickest under mountains; thinnest beneath ocean – Between 5 – 70 km thick – Crust beneath oceans = oceanic crust • Made up of BASALT – dark rock/fine texture – Crust that forms continents = continental crust • Made mainly of GRANITE – light color/coarse texture

The Mantle • layer of hot rock (but solid) • Over 3, 000 km thick • Divided into 2 layers 1. Upper Mantle a. Lithosphere – crust and uppermost part of the mantle; about 100 km thick b. Asthenosphere – upper mantle just below the lithosphere a. Hotter and under more pressure b. Softer/bends like plastic (but still solid) 2. Lower Mantle

The Core • Made up of metals iron and nickel • 2 parts… • OUTER CORE – layer of molten metal that surrounds the inner core • INNER CORE – dense ball of solid metal – Pressure squeezes the atoms of nickel and iron so much to where they cannot spread out, so they become solid • Scientists think the movements in the liquid of the outer core create Earth’s magnetic field

Spell o roma Lith (o sphere) As then (o sphere)

Review Questions 1. Why is it difficult to determine Earth’s inner structure? 2. What is the difference between the lithosphere and the asthenosphere? 3. How do temperature and pressure change as you go deeper into the Earth? 4. How are oceanic and continental crusts alike and different? 5. Place these terms in correct order so they begin at Earth’s surface and move toward the center: inner core, asthenosphere, crust, lithosphere, and outer core

More Review Questions 6. Write whether each statement is true or false a. continental crust is made up of rocks such as granite b. the relatively soft layer of the mantle is called the asthenosphere c. the Earth’s core is made up of iron and copper