Transcript How landforms came to be!

Chapter 1 - Lesson 1
Earth’s Landforms
How Landforms Came to Be
Turn to textbook page 14
• Voices: Poetry and Art from Around the World
Berlin, Germany
Tokyo, Japan
Juarez, Mexico
How Landforms Came to Be
Textbook page 20
• Earth is mostly covered in water
• There are landforms on the remaining parts of
the Earth
• Landforms are natural features on the Earth’s
surface
• Examples: mountains, hills, plains
How Landforms Came to Be
• Earth’s landforms and continents were formed
through the theory of plate tectonics
• Plate tectonics says that the Earth is made up
of several large, slow moving slabs or plates
• The continents and ocean floors form the tops
of the plates which move and carry the
continents and ocean floors with them
How Landforms Came to Be
• 13 Major Tectonic Plates of the World
How Landforms Came to Be
• Scientists believe that long ago the Earth’s
landmasses made up one giant super
continent called Pangaea
How Landforms Came to Be
How Landforms Came to Be
• Scientists believe that forces inside the Earth
caused Pangaea to break apart
• Continental drift is a theory that explained
how continents shift position on Earth's
surface.
• Set forth in 1912 by Alfred Wegener, a
geophysicist and meteorologist, continental
drift also explained why look-alike animal and
plant fossils, and similar rock formations, are
found on different continents.
How Landforms Came to Be
Alfred Wegener
How Landforms Came to Be
• Who came up with the theory of Continental
Drift? What brought him to the conclusion of
a super continent?
How Landforms Came to Be
• Earth is made up of layers similar to an apple
• Earth has a crust, mantle, core just as an apple has skin, meat,
and a core
• Earth’s crust is 10 to 25 miles thick
• Earth’s mantle lies just below the crust and is 1,800 miles
thick
• The mantle is made of hot, rocklike materials
• Earth’s center or core is very hot, temperatures can be 5,000
degrees Fahrenheit
• The core is broken into two parts the inner core and the outer
core
• The inner core is solid and the outer core is molten or melted
rock
How Landforms Came to Be
• The liquid outer core surrounds the inner core and is believed
to be composed of iron mixed with nickel and trace amounts
of lighter elements
• Recent studies suggests that the innermost part of the core is
enriched in gold and platinum while also containing nickel and
primarily iron
• Extreme heat from the core causes the mantle to create
pressure on the crust, forcing the crust in some places to rise
• As the crust rises it pushes large blocks or rock upwards and
forms mountains or plateaus
• A portion of the Rocky Mountains formed this way
How Landforms Came to Be
• Mg – Magnesium, Fe – Iron, Al – Aluminum, Si
– Silicate, O – Oxygen, Ni – Nickel,
Au –
Gold, Pt - Platinum
How Landforms Came to Be
How Landforms Came to Be
• Mountains can also be formed when one plate
over another plate
• The Earth’s plates are constantly moving even
today
• The movement of plates sometimes shakes
the Earth’s surface causing an earthquake
• Earthquakes are common around faults
• Fault – is a break in the Earth’s crust where
movement occurs between the plates
How Landforms Came to Be
• The San Andreas Fault in California is one of
the most well known faults in the world
• Most faults are not visible, but the San
Andreas Fault is visible
How Landforms Came to Be
• The 1906 Earthquake in San Francisco, California was caused
by the movement of the plates that meet at the San Andreas
Fault
• The San Andreas Fault shifted 21 ft
• What are the 4 layers of the Earth called and
what do they consist of?
Terms to Know
• Plate Tectonics
• Continental Drift
• Fault
• How do moving tectonic plates create
landforms such as mountains?