The layers of the planet Earth

1. THE
STRUCTURE
OF THE
EARTH
Plate Tectonics
Kella Randolph B.S., M.Ed.
https://upload.wikimedia.org/wikipedia/commons/thumb/5/53/Bernese_Alps.jpg/1200px-Bernese_Alps.jpg

2. Structure of the
Earth
The planet is made up of three main
layers:
Core (and inner core)
Mantle
Crust
https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/1095/2016/11/03155304/OSC_Astro_08_01_Interior.jpg

3. CONTINENTAL CRUST COLLIDES WITH
OCEANIC CRUST
This Photo by Unknown Author is licensed under CC BY-SA
https://i.stack.imgur.com/hC34M.gif
Subduction

4. The Crust Earth’s crust is made of two
types:
• Continental Crust
• .Thick (10-70km)
• Buoyant (less dense than oceanic
crust)
• Mostly old
• Oceanic Crust
• Thin (~ 7 km)
• Dense (sinks under continental
crust)
• Young
https://upload.wikimedia.org/wikipedia/commons/thumb/e/e7/Continental_and_oceanic_crust.png/220px-
Continental_and_oceanic_crust.png

5. How do we know
what the earth is
made of?
• Geophysical surveys: seismic, gravity,
magnetics, electrical, geodesy
• Geological surveys: fieldwork, boreholes, mines
• Undersea exploration: sonar, Deep Sea
Challenger
• Satellite exploration of Earth: GPS, GOES
• Images/ Satelliets:
https://upload.wikimedia.org/wikipedia/commons/thumb/9/98/Nasa_earth_observatories.jpg/500px-
Nasa_earth_observatories.jpg
• Geologists : https://get.pxhere.com/photo/landscape-adventure-skyscraper-extreme-sport-
concrete-mountaineering-construction-site-team-geology-foundation-site-kempten-new-building-
construction-workers-brewhouse-growing-region-geological-phenomenon-802265.jpg
• Deep Sea Exploration: https://i.vimeocdn.com/video/473711917.jpg?mw=1920&mh=1080&q=70

6. What is Plate
Tectonics?
Earth’s crust is divided into 12 major
plates which are moved in various
directions.
• The plates collide, pull apart, or scrape
against each other.
• Each motion causes different types of
features on the Earth’s crust.
• The word, tectonic, refers to changes in
the crust because of plate interaction.
https://englishiscoolsite.files.wordpress.com/2016/05/world_7colour_conamed.jpg?w=1607&h=1147&crop=1

7. IF YOU LOOK AT A MAP OF
THE WORLD, YOU MAY
NOTICE THAT SOME OF
THE CONTINENTS COULD
FIT TOGETHER LIKE
PIECES OF A PUZZLE.
https://intarch.ac.uk/journal/issue26/world-map.gif

8. World Plates
https://upload.wikimedia.org/wikipedia/commons/thumb/8/8a/Plates_tect2_en.svg/1200px-Plates_tect2_en.svg.png

9. What are tectonic
plates made of?
• What are tectonic plates made of?
• The lithosphere is made up of the
crust and the upper part of the mantle.
https://upload.wikimedia.org/wikipedia/commons/thumb/0/07/Earth-crust-cutaway-english.png/350px-Earth-crust-cutaway-
english.png

10. What lies beneath the tectonic plates?
Below the
lithosphere
(which makes
up the tectonic
plates) is the
asthenosphere.
https://upload.wikimedia.org/wikipedia/commons/thumb/0/07/Earth-crust-cutaway-english.png/350px-Earth-crust-cutaway-english.png

11. PLATE
MOVEMENT
“Plates” of lithosphere are moved
around by the underlying hot
mantle convection cells
http://www.thegeographeronline.net/uploads/2/6/6/2/26629356/2378764_orig.jpg