44
Do Now # 4 • What is the difference between convergent, divergent, and transform boundaries?

Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Embed Size (px)

Citation preview

Page 1: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Do Now # 4

• What is the difference between convergent, divergent, and transform boundaries?

Page 2: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Answer

• Convergent move towards each other, divergent move away from each other, and transform slide past each other.

Page 3: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Agenda

• Do Now

• L.T/Lg. T

• Notes on Plate Tectonics

Page 4: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Learning/Language Target

• L.T- By the end of class I will be able to explain what plate tectonics are.

• Lg.T By the end of class I will take notes on plate tectonics and label plate boundaries.

Page 5: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Structure of the Earth

• The Earth is made up of 3 main layers:– Core– Mantle– Crust

Inner core

Outer core

Mantle

Crust

Page 6: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

The Crust• This is where we live!

• The Earth’s crust is made of:

Continental Crust

- thick (10-70km)- buoyant (less dense than oceanic crust) - mostly old

Oceanic Crust

- thin (~7 km)- dense (sinks under continental crust)- young

Page 7: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

How do we know what the Earth is made of?

• Geophysical surveys: seismic, gravity, magnetics, electrical, geodesy– Acquisition: land, air, sea and satellite

– Geological surveys: fieldwork, boreholes, mines

Page 8: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

What is Plate Tectonics?

Page 9: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

• 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.

Page 10: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Pangea

Page 11: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Plate Tectonics• The Earth’s crust is divided into 12 major

plates which are moved in various directions.• This plate motion causes them to collide, pull

apart, or scrape against each other.• Each type of interaction causes a

characteristic set of Earth structures or “tectonic” features.

• The word, tectonic, refers to the deformation of the crust as a consequence of plate interaction.

Page 12: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

World Plates

Page 13: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

What are tectonic plates made of?

• Plates are made of rigid lithosphere.

The lithosphere is made up of the crust and the upper part of the mantle.

Page 14: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

What lies beneath the tectonic plates?

• Below the lithosphere (which makes up the tectonic plates) is the asthenosphere.

Page 15: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Plate Movement• “Plates” of lithosphere are moved around by

the underlying hot mantle convection cells

Page 16: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Practical Exercise 1

Supercontinents!

Page 17: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

What happens at tectonic plate boundaries?

Page 18: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

• Divergent

• Convergent

• Transform

Three types of plate boundary

Page 19: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

• Spreading ridges– As plates move apart new material is erupted to

fill the gap

Divergent Boundaries

Page 20: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Age of Oceanic Crust

Courtesy of www.ngdc.noaa.gov

Page 21: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

• Iceland has a divergent plate boundary running through its middle

Iceland: An example of continental rifting

Page 22: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

• There are three styles of convergent plate boundaries– Continent-continent collision– Continent-oceanic crust collision– Ocean-ocean collision

Convergent Boundaries

Page 23: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

• Forms mountains, e.g. European Alps, Himalayas

Continent-Continent Collision

Page 24: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Himalayas

Page 25: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

• Called SUBDUCTION

Continent-Oceanic Crust Collision

Page 26: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

• Oceanic lithosphere subducts underneath the continental lithosphere

• Oceanic lithosphere heats and dehydrates as it subsides

• The melt rises forming volcanism

• E.g. The Andes

Subduction

Page 27: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

• When two oceanic plates collide, one runs over the other which causes it to sink into the mantle forming a subduction zone.

• The subducting plate is bent downward to form a very deep depression in the ocean floor called a trench.

• The worlds deepest parts of the ocean are found along trenches. – E.g. The Mariana Trench is 11 km deep!

Ocean-Ocean Plate Collision

Page 28: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?
Page 29: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

• Where plates slide past each other

Transform Boundaries

Above: View of the San Andreas transform fault

Page 30: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?
Page 31: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Practical Exercise 2

Where will the UK be in:1,000 years?

1,000,000 years?

1,000,000,000 years?

Page 32: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

…what’s the connection?

Volcanoes and Plate Tectonics…

Page 33: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Volcanism is mostly focused at plate margins

Pacific Ring of Fire

Page 34: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

- Subduction - Rifting - Hotspots

Volcanoes are formed by:

Page 35: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Pacific Ring of Fire

Hotspot volcanoes

Page 36: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

• Hot mantle plumes breaching the surface in the middle of a tectonic plate

What are Hotspot Volcanoes?

Photo: Tom Pfeiffer / www.volcanodiscovery.com

The Hawaiian island chain are examples of hotspot volcanoes.

Page 37: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

The tectonic plate moves over a fixed hotspot forming a chain of volcanoes.

The volcanoes get younger from one end to the other.

Page 38: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

…what’s the connection?

Earthquakes and Plate Tectonics…

Page 39: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

• As with volcanoes, earthquakes are not randomly distributed over the globe

• At the boundaries between plates, friction causes them to stick together. When built up energy causes them to break, earthquakes occur.

Figure showing the distribution of earthquakes around the globe

Page 40: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Where do earthquakes form?

Figure showing the tectonic setting of earthquakes

Page 41: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Tsunami Vs. Earthquake

• Tsunamis are giant waves created by underwater earthquakes.

• Earthquakes are created when any of the plates move or “slip.”

Page 42: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?
Page 43: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?

Plate Tectonics Summary• The Earth is made up of 3 main layers (core,

mantle, crust)• On the surface of the Earth are tectonic

plates that slowly move around the globe• Plates are made of crust and upper mantle

(lithosphere)• There are 2 types of plate• There are 3 types of plate boundaries• Volcanoes and Earthquakes are closely

linked to the margins of the tectonic plates

Page 44: Do Now # 4 What is the difference between convergent, divergent, and transform boundaries?