Plate Tectonics Mrs. Anton. Continental Drift Caused By Plate Tectonics.
Science10: Earth Science Movement of Plate Tectonics
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Name: ____________________________________ Block: _____________ Date: ___________________________ Science 10: Features of Plate Tectonics 1 Science 10: Earth Science Movement of Plate Tectonics Why do tectonic plates move? Fluids – substances in which the particles can flow freely, such as . Convection – the transfer of heat within a fluid and with the movement of fluid from one place to another. There is also a transfer of as well as heat (conduction only transfers heat). Using the Kinetic Molecular Theory (KMT)… As particles move faster and their energy , they move farther apart. As the particles move apart, the fluid and becomes dense. *density = mass/volume, so if the volume increases, the density decreases In a pot of boiling water, the warm water with decreased density rises to the top because it is less dense than the surrounding water. At the surface the water is cooled and contracts so the density increases and the water sinks where it is reheated and the recirculated. Convection current – the movement of a fluid caused by , the continuous cycling of heating, cooling and reheating. So why do tectonic plates move? *Hint: which layer of the Earth is a fluid? Tectonic plates push and pull Rising magma reaches Earth’s surface at spreading centres. If the spreading centre occurs in the ocean it is called a ridge or ridge. If it occurs on land, which is less common, it is called a . As magma at the surface and makes new material it pushes the older material aside and the tectonic plates move away from the ridge. This is called . As plates are pushed away from each other, they collide with other plates on the other side. If one plate is more dense than the other, occurs. This is the act of one plate . As the edge of a tectonic plate subducts deep into the mantle, it pulls the rest of the plate with it. This process is called . Subduction zones experience .
Transcript of Science10: Earth Science Movement of Plate Tectonics
Name: ____________________________________ Block: _____________ Date: ___________________________
Science 10: Features of Plate Tectonics 1
Science 10: Earth Science Movement of Plate Tectonics
Why do tectonic plates move?
Fluids – substances in which the particles can flow freely, such as . Convection – the transfer of heat within a fluid and with the movement of fluid from one place to another. There is also a transfer of as well as heat (conduction only transfers heat). Using the Kinetic Molecular Theory (KMT)… As particles move faster and their energy , they move farther apart. As the particles move apart, the fluid and becomes dense. *density = mass/volume, so if the volume increases, the density decreases
In a pot of boiling water, the warm water with decreased density rises to the top because it is less dense than the surrounding water. At the surface the water is cooled and contracts so the density increases and the water sinks where it is reheated and the re-‐circulated.
Convection current – the movement of a fluid caused by , the continuous cycling of heating, cooling and reheating. So why do tectonic plates move? *Hint: which layer of the Earth is a fluid? Tectonic plates push and pull Rising magma reaches Earth’s surface at spreading centres. If the spreading centre occurs in the ocean it is called a ridge or ridge. If it occurs on land, which is less common, it is called a . As magma at the surface and makes new material it pushes the older material aside and the tectonic plates move away from the ridge. This is called . As plates are pushed away from each other, they collide with other plates on the other side. If one plate is more dense than the other, occurs. This is the act of one plate . As the edge of a tectonic plate subducts deep into the mantle, it pulls the rest of the plate with it. This process is called . Subduction zones experience .
Name: ____________________________________ Block: _____________ Date: ___________________________
Science 10: Features of Plate Tectonics 2
Science 10: Earth Science
Features of Plate Tectonics A plate boundary is where two tectonic plates are in contact. There are three main types of plate interaction: 1. Divergent:
2. Convergent:
3. Transform: A. Divergent plate boundaries
Divergent plate boundaries mark the areas where tectonic plates are spreading apart. Plates that are spreading apart are called diverging plates. The is a system of spreading ridges running down the middle of the Atlantic Ocean. On land, at the , diverging plates are slowly breaking apart Africa. B. Convergent plate boundaries A convergent plate boundary occurs where tectonic plates . There are three types of convergent plate boundaries. 1.
2.
3. (1) Oceanic-‐continental plate convergence When a dense oceanic plate collides with a continental plate, the dense oceanic plate is forced the less dense continental plate. A deep underwater valley called a is formed where the tectonic plates make contact. As the subducting plates move deeper, large pieces melt off. Most crystallize, but some magma can work its way to the surface, forming . We see this here! The oceanic plate subducts under the continental plate. This convergent boundary is called the Cascadia subduction zone. A long chain of volcanoes, called a volcanic has formed along North America’s west coast. The force of the collision causes the continental plate to fold and create . Here, this collision caused British Columbia’s Coast Mountains and Cascade Mountain Range. Pressure builds up as long as the plates remain stuck in place. When the stress is too great, the is released causing an .
Chapter 12 Thermal energy transfer drives plate tectonics. • MHR 523
Plate InteractionsA region where two tectonic plates are in contact is known asa plate boundary (Figure 12.17). The interaction of tectonicplates has played an important role in both the geological andthe biological history of Earth. There are three main types ofplate interaction: divergence (spreading apart), convergence(moving together), and transform (sliding by). The way inwhich tectonic plates interact depends on two main factors:• the type of plate• the direction the plates are moving relative to one another
Divergent plate boundaries Divergent plate boundaries mark the areas where tectonicplates are spreading apart (Figures 12.18). Plates that arespreading apart are known as diverging plates. The Mid-Atlantic Ridge, for example, is a system of spreading ridgesthat is separating the Americas from Africa, Europe, and Asia.About 16 000 km long, the Mid-Atlantic Ridge is the largestmountain range on Earth, with the greatest amount ofvolcanic activity.
In the ocean, sea floor spreading causes plates to separate.A similar process can occur on the continents. For example,diverging plates at the East African Rift are slowly breakingAfrica into pieces.
Figure 12.18 A spreading centre at a divergentplate boundary (A). The East African Rift (B)
Figure 12.17 Tectonic plate boundaries
PacificPlate
North AmericanPlate
SouthAmerican
Plate
African Plate
Eurasian Plate
PacificPlate
Indo-AustralianPlate
AntarcticPlate
AntarcticPlate
PhilippinePlate
NorthAmerican
Plate
Cocos Plate
Scotia Plate
ArabianPlate
NazcaPlate
CaribbeanPlate
Juan De FucaPlate
Convergent boundaryDivergent boundaryTransform faultTransform boundaryPlate movement
crust
crust
upper mantle
asthenosphere
spreading centre
upper mantle
lithosphere
A
B
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Science 10: Features of Plate Tectonics 3
(2) Oceanic-‐oceanic plate convergence
When two oceanic plates collide, cooling causes one plate to be dense than the other, forcing it to into the mantle. This can cause a long chain of volcanoes called a volcanic such as , and the Aleutian Islands of Alaska. These regions also experience earthquakes.
(3) Continental-‐continental plate convergence When continental plates converge, subduction does NOT take place. This is because continental plates are to subduct into the mantle. As the plates collide, they and causing mountain ranges such as the Himalayas. The Himalayas were formed when the continent collided with the continent 40-‐50 million years ago. The Indian plate is still colliding with the Asian plate causing the Himalayans to increase in elevation by several centimetres every . C. Transform plate boundaries
Convection currents in the can cause plates to slide past each other. These transform plate boundaries usually occur near . Because the plates slide past each other, no or form. However, earthquakes and faults may result. A fault is a break in rock layers due to movement on either side and a fault is a fault that occurs at a transform plate boundaries.
What is a ‘hot spot’? A hot spot is an area where molten rock rises to Earth’s surface, creating . *This !!!
