Basic structure of the earth
Download
1 / 21

Basic Structure of the Earth - PowerPoint PPT Presentation


  • 57 Views
  • Uploaded on
  • Presentation posted in: General

Basic Structure of the Earth. Definitions. Pressure – amount of force acting on a surface Plastic - Capable of undergoing continuous deformation without rupture or relaxation Convection – Transfer of heat (energy) through the movement of mass Density – mass per unit volume, g/cm 3

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Basic Structure of the Earth ' - makara


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Definitions
Definitions

  • Pressure – amount of force acting on a surface

  • Plastic - Capable of undergoing continuous deformation without rupture or relaxation

  • Convection – Transfer of heat (energy) through the movement of mass

  • Density – mass per unit volume, g/cm3

  • Seismic – having to do with earthquakes







Compositional
Compositional

Mechanical




Earth s layered structure

Layers Defined by Composition

Earth’s Layered Structure

 Earth’s interior consists of three major zones defined by their chemical composition—the crust, mantle, and core.

 Crust

• Thin, rocky outer layer

• Varies in thickness

- Roughly 7 km in oceanic regions

- Continental crust averages 8–40 km

- Exceeds 70 km in mountainous regions


Earth s layered structure1

Layers Defined by Composition

Earth’s Layered Structure

 Crust

• Continental crust

- Upper crust composed of granitic rocks

- Lower crust is more akin to basalt

- Average density is about 2.7 g/cm3

- Up to 4 billion years old


Earth s layered structure2

Layers Defined by Composition

Earth’s Layered Structure

 Crust

• Oceanic crust

- Basaltic composition

- Density about 3.0 g/cm3

- Younger (180 million years or less) than the continental crust


Earth s layered structure3

Layers Defined by Composition

Earth’s Layered Structure

 Mantle

• Below crust to a depth of 2900 kilometers

• Composition of the uppermost mantle is the igneous rock peridotite (changes at greater depths).


Earth s layered structure4

Layers Defined by Composition

Earth’s Layered Structure

 Core

• Below mantle

• Sphere with a radius of 3486 kilometers

• Composed of an iron-nickel alloy

• Average density of nearly 11 g/cm3


Earth s layered structure5

Layers Defined by Physical Properties

Earth’s Layered Structure

 Lithosphere

• Crust and uppermost mantle (about 100 km thick)

• Cool, rigid, solid

 Asthenosphere

• Beneath the lithosphere

• Upper mantle

• To a depth of about 660 kilometers

• Soft, weak layer that is easily deformed


Earth s layered structure6

Layers Defined by Physical Properties

Earth’s Layered Structure

 Mesosphere (lower Mantle)

• 660–2900 km

• More rigid layer

• Rocks are very hot and capable of gradual flow.


Earth s layered structure7

Layers Defined by Physical Properties

Earth’s Layered Structure

 Inner Core

• Sphere with a radius of 1216 km

• Behaves like a solid

 Outer Core

• Liquid layer

• 2270 km thick

• Convective flow of metallic iron within generates Earth’s magnetic field



Earth s layered structure9

Discovering Earth’s Composition

Earth’s Layered Structure

 Crust

• Early seismic data and drilling technology indicate that the continental crust is mostly made of lighter, granitic rocks.

 Mantle

• Composition is more speculative.

• Some of the lava that reaches Earth’s surface comes from asthenosphere within.

 Core

• Earth’s core is thought to be mainly dense iron and nickel, similar to metallic meteorites. The surrounding mantle is believed to be composed of rocks similar to stony meteorites.


Facts
Facts

  • We only know about the core through studying seismic (earthquake) waves and volcanic rocks

  • Deepest well ever drilled was only 12 km deep

  • The crust is only 1% of earth’s mass

  • The mantle is about 65% of earth’s mass

  • The core is about 34% of earth’s mass

  • Pressure at the center of the earth is about 3.3 million atmospheres

  • The temperature in the center of the earth is roughly the same as the surface of the sun


ad
  • Login