Earth’s InteriorChapter-1 Section-1

By: Ms. VigilScience P-1

9/6/04

What is the Science of Geology?

Earth’s hard surface is formed of rock

Geology is the study of the planet Earth

earth’s landforms are the work of

natural forces that slowly build up

and wear down the land

The earth looks very different than

it did thousands of years ago.

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What are Surface Changes?

Constructive forces: shape the surface by building up mountains and landmasses. Example: volcanoes, etc.

Destructive forces: shape the surface by slowly wearing away mountains and other features. EROSION

Example: ocean waves, rain, wind, etc.

Continents

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Is there indirect evidence of what’s inside the Earth?

Geologists cannot observe Earth’s interior directly via seismic waves

It is over 6,000 kilometers from the surface to the center of the Earth

Seismic Activity –when earthquakes occur they produce seismic waves

Seismic waves travel through the earth—the speed of the seismic waves and the paths they take reveal how the planet is put together

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What is Temperature in the Center of the Earth like?

At first as you descend it becomes cool, however,

20 meters + rock is getting warmer

For every 40 m descended, the temperature rises 1 degrees celsius

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What is Pressure in the Center of the Earth like?

Pressure is the force pushing on a surface area

The deeper you go, the greater the pressure

Three main layers in the Earth Crust Mantle Core

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What is the Crust?

The layer of rock that forms Earth’s outer skin Mountains, rocks, soil & water make-up the

surface Ranges from 5 to 40 kilometers

The crust includes both oceanic crust and continental crust Basalt –type of rock that is dark and dense with a fine texture – is

found primarily on the ocean floor

Granite – type of rock that has large crystals and is light in color and is found primarily on the land

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What is the Mantle

A layer of hot rock Made of two parts major parts at the

uppermost part of the Mantle: Lithosphere and Asthenosphere

Lithosphere Uppermost part of the mantle and lower

part of crust which together form a rigid layer approx. 200 km thick

Lithos means stone

Asthenosphere Below the lithosphere Soft like tar—it can bend like plastic

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What is the core?

The core consists of two parts: Liquid Outer Core and a Solid Inner Core

Outer Core: Layer of molten metal that

surrounds the inner core –like a thick liquid

Inner Core Is a dense ball of solid metal Extreme pressure squeezes the atoms of iron

and nickel into a tight solid that can’t become a liquid

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How does the Earth’s Magnetic Field Work

Currents in the liquid outer core force the solid inner core to spin at a slightly faster rate than the rest of the planet

These currents in the outer core creates Earth’s magnetic field—causes the earth to act like a gigantic bar magnet

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Exploring Earth’s Interior pg. 22-23

Complete project

Scientific drawings of the Earth’s Interior p.22 and a Cross section from Earth’s surface to the center –pg 23. (These drawings are to be taped or glued into the Science journal)

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Summarize: HOMEWORK

Geology Constructive & Destructive Forces Seismic waves Temp & Pressure in Earth Crust Mantle Core Earth’s magnetic field