Lesson 8: Shape,Size and Structure of the earth

The Shape, Size & Structure of the Earth

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The Earth was formed at the same time as the other planets of the Solar System from a vast spinning disc of gas and dust.

4.5 Billion years ago

Scientists have gathered valuable information about the Earth with the use of advance science and technology to help us understand our planet.

They have determined the size and shape of the Earth by using precise instruments and equipment.

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OF THE EARTH

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SHAPEOF THE EARTH

The Earth is a rotating object.

Its rotation produces a Centrifugal force which opposes gravity.

The Earth is shaped like an Orange

because it bulges at the Equator and is flat at the polar regions.

SHAPEOF THE EARTH

Therefore, the Earth is an Oblate Spheroid.

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Sizeof the Earth

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Geodesy – the science that studies and measures the exact size and dimensions of the Earth.

Size of the Earth

Equatorial circumference 40,075.03 km.

Polar circumference 40,007.88 km.

Equatorial diameter 12,756.28 km.

Polar diameter 12,713.51 km.

The latest survey

about the dimensions

of the Earth are as

follows:

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of the EarthStructure

of the EarthStructure

Barysphere

Mesosphere

Lithosphere

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•The rocky outermost layer of lithosphere.

Structureof the Earth

Crust

Composed of two kinds:

1. Silicon –

2. Aluminum - the upper layer of the Earth’s crust.

It is made up largely of

granitic rocks which are

lighter in color and weight.

32-48 km.

•The rocky outermost layer of lithosphere.

Structureof the Earth

Crust

Composed of two kinds:

1. Silicon –

2. Magnesium – submerged layer of the lithosphere.

Magnesium makes up the

ocean floor. It is also known as

Oceanic Crust.

5-8 km. thick

•The middle layer of the Earth

Structureof the Earth

Mantle

It is composed of dense rocks largely made up of the mineral olivine.

Asthenosphere – an upper

rock materials of the upper mantle.

- Allows the crustal plates lying on

it to move in either a vertical or

horizontal manner

2,900 km. thick

•The innermost portion of the Earth

Structureof the Earth

Core

•It is believed to be metallic.

•Composed of iron and nickel (NIFE)

3,400 km. thick

Nickel from NIIron from FE

Structureof the Earth

Core

a. inner core – solid about

1,150 km. thick w/ an

extremely high

temperature (2,200°C).

b. outer core – made up of

molten rock about 2,250

km. thick.

TWO PARTS–

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