Plate Tectonics Test
Why didn't other Scientists believe Wegener?
1) The continents move slowly so it wasn't something that could be easily seen or measured. 2) Wegener couldn't explain what forces were causing the continents to move.
viscosity
A liquid's resistance to flow
volcano
A vent in Earth's crust through which melted - or molten - rock flows
How do hot spot volcanoes form?
A volcano forms above a hot spot when magma erupts through the crust and reaches the surface.
what is a surface wave
A wave that travels along a surface it is responsible for all damage during an earthquake
____ can explode out of a volcano up to 40 km into the air.
Ash columns
what are the three forces that interact to cause tectonic plate motion
Basel drag,Ridge push, and slab pull
Suggests: Caledonian and Appalachian mountain were connected as one mountain range in the past, and then
Broke apart into two as the continents drifted apart
The Blank mountain range in Europe and the Blank mountain range in North America are composed of rocks that are the same type, age, and structure. When lining up the continents these mountain ranges also connect almost perfectly to form a united belt across the two continents.
Caledonian; Appalachian
Glacial grooves in America, Africa, India, and Australia. This would suggest that these continents were once part of the Southern Hemisphere and had a
Colder climate
Rock Clue:s: Wegener observed that mountain ranges and rock formations on different continents had
Common origins
convergent plate boundary
Continental -> <- Continental and creates folded mountains Continental -> <- Oceanic and creates volcanoes and deep ocean trench Oceanic -> <- Oceanic and creates trench and island arc
Alfred Wegener came up with the
Continental Drift Hypothesis
transform plate boundary
Continental | | Continental - earthquake Continental | | Oceanic - earthquake Oceanic | | Oceanic - earthquake
Fossils from the same plants and animals have been found on multiple
Continents
Materials move based on differences in their temperatures and densities in the process of ......
Convection
Where does a Normal fault occur
Divergent plate boundary
Climate Clues: Wegener discovered
Glacial grooves
What is NOT true about lava?
Lava is inside the Earth
The hypothesis became more widely accepted after Wegener's death when evidence of blank blank spreading was found deep within the blank.
Sea floor; ocean
What is true about lava flows?
Slow moving, but can last for a long time
What wave is the most destructive and why
Surface because it travels only on the crust
Waht makes up the asthenosphere
The layer below the rigid lithosphere is a zone of asphalt-like constancy called the Asthenosphere . The asthenosphere is the part of the mantle that flows and moves the plates of the Earth.
What is the focus?
The point in the earth where the earthquake starts
How do tectonic plates move?
They float on top of very hot "plasticy" rock and convection currents from the mantel
moment magnitude scale
a rating system that estimates the total energy released by an earthquake
Modified Mercalli Scale
a scale that rates the amount of shaking from an earthquake
What is a strike-slip fault?
a type of fault where rocks on either side move past each other sideways
Most of the volcanic activity on Earth occurs
along mid-ocean ridges
Earth's plastic-like layer is the _____.
asthenosphere
Continental Drift Hypothesis that the continents are in
constant motion on Earth's surface
Remains of the same plants and animals are present on different _____ that are now separated by oceans.
continents
What is the boundary where two plates collide? *
convergent
Active volcanoes are most likely to form at ____.
convergent oceanic-continental boundaries
Where do reverse faults occur?
convergent plate boundaries
As magma rises toward Earth's surface, the pressure on it
decreases
What is the boundary where two plates separate? *
divergent
The eruption style of a volcano depends on the amount of ______ dissolved in the magma, especially the amount of water vapor
gases
What formed the Hawaiian islands?
hot spot volcano
At an ocean/ocean divergent boundary, what is CREATED? *
mid-ocean ridge
What happens when the heat from a volcano melts the snow and ice on the summit?
mudflow
divergent plate boundary
oceanic <- -> oceanic and creates mid-ocean ridge continental <- -> continental and creates rift valley
What can S waves travel through?
only solids
Alfred Wegener came up with his hypothesis from the fact that the continents look like they could fit together like the
pieces of a puzzle
Plate movement happens at...
plate boundaries
Where do faults occur?
plate boundaries
The place where two plates meet is called a ....
plate boundary
Viscosity of lava is higher when magma has a high ___ content *
silica
How do transform boundaries move?
slide past each other
What can P waves travel through?
solids and liquids
volcanic ash
tiny particles of pulverized volcanic rock and glass
What is the boundary where two plates slide past each other? *
transform
Where do strike-slip faults occur?
transform boundaries
Most volcanoes in the US occur along the ____ coast
west
slab pull
when a plate sinks below another plate it pulls on then rest of the plate
About how many different volcanoes erupt each year?
60
There are about _____ active volcanoes on land.
600
What happens when two continental plates collide
A Mountain forms
What could form when one tectonic plate dives under another plate
A Volcano
What happens when a Continental and oceanic plate collide
A deep ocean trench forms
volcanic ash
A mixture of particles of pulverized volcanic rock and glass
Low silica content - mid-ocean ridges and hot spots
Low viscosity and flows easily
Hot Spot (PLUME)
New volcano forms as tectonic plates move over a plume. When the plate moves away from a plume, the volcano becomes dormant/inactive. A chain of volcanoes forms as the plate moves. The oldest volcano is farthest away from the hot spot and the youngest volcano is directly above the hot spot.
When a continental and oceanic plate collides which one subducts
Oceanic plate subducts
How do tectonic plates move in relationship to the mantel
Plates at our planet's surface move because of the intense heat in the Earth's core that causes molten rock in the mantle layer to move
Where do volcanoes form? Why? (rof)
Ring of Fire: An area of earthquake and volcanic activity surrounding the Pacific Ocean. Most volcanoes occur along convergent plate boundaries. They also occur along divergent plate boundaries and over hot spots. Volcanoes form along the Pacific Plate and are called the Ring of Fire.
What is an example of a transform plate boundary
San Andreas Fault in California
Why did Wegener's hypothesis become more accepted after his death
Sea floor spreading was found/Descovered
Mudflows (lahars)
The thermal energy a volcano produces during an eruption can melt snow and ice on the summit. This meltwater can then mix with mud and ash on the mountain to form this.
Do tectonic plates move fast or slow?
They move slowly (about the speed of which a fingernail grows)
_____, made up of tiny particles of pulverized volcanic rock and glass erupts explosively.
Volcanic Ash
Hot spots
Volcanoes that are not associated with plate boundaries
How do tectonic plates move in relationship to other plate
When the plates meet. The movement of the plates creates three types of tectonic boundaries
Is Mt. Vesuvius, Yellowstone National Park in Wyoming, the Hawaiian Islands, or Andes Mountains a continental hot spot?
Yellowstone National Park in Wyoming
What are convection currents?
a current in a fluid that results from convection.
Where most earthquakes occur
along plate boundaries and along the edges of continents and in oceans
What is a volcano?
A weak spot in the crust where molten material, or magma, comes to the surface.
Who came up with the Continental drift hypotheses
Alfred wegener
What is the Ring of Fire?
An area located along the Pacific Ocean where 80% of the worlds earthquakes and many active volcanoes occur
What happens when two oceanic plates collide
And Island arc forms
What is a earthquake?
Are the vibrations in the ground that result from movement along break in Earth's lithosphere.
What does dissolved gases do to magma
As magma moves towards the surface pressure from the rock above decreases and so does the ability for the gases to stay dissolved in the magma. Eventually bubbles form, they increase in size and gas begins to escape. This can be hard for high viscosity lavas It can end in a explosive eruptions
Lava flow
Lava flows move slowly, but can be damaging and threaten communities. They can also last a long time.
What are the effects of each type of eruptions
Lava flows, Ash falls, Mud flows, and it can affect climate
Lava
Magma that reaches Earth's surface
silica (how does it affect magma)
Main chemical compound in all magmas. Differences in the magma's silica can affect thickness and viscosity.
Blank blank on the Western coast of Africa and the Eastern coast of South America are identical in both chemistry and age
Volcanic rocks
What are the positive environmental impacts of the volcanoes
Volcanoes have also helped create a large portion of Earth's atmosphere provide nutrients to the surrounding soil
How do convergent volcanoes form
When a continental and oceanic plate boundary collide the oceanic subducts. the thermal energy below the surface melt the subducting plate and form magma. The magma is less dense than the mantel so i rises through cracks in the crust
How do divergent plate volcanoes form
When the two plates spread apart magma rises through the opening in earths crust that forms between the two plates
what is a fault
a break in Earth's lithosphere where one block of rock moves toward, away from, or past another
silica
a material found in magma that forms from the elements oxygen and silicon
How do seismic waves tell what earth is made of
S-waves can only travel through solids, and on a map graph thingie it shows that they stop when they reach the outer core
What causes the formation of volcanoes?
Scientists have learned that the movement of Earth's tectonic plates cause the formation of volcanoes and the eruptions that result.
Who is Mickey Mouse?
Sodapop's horse
_____________ occurs where plates of different densities collide.
Subduction
The release of a large amount of volcanic ash can affect Earth's climate by blocking ___. When droplets of sulfuric acid from volcanoes form in the atmosphere, they ____ sunlight into space. Volcanic ash and acid droplets in the atmosphere ___ Earth's temperature *
Sunlight; reflect; lower
Name the two mountain ranges (one in N. America and one in Europe) and explain what characteristics proved that they were once together.
The Appalachian Mountains in North America and the Caledonian Mountains in Europe are similar in age and rock structure. If you connected North America and Europe, they would make one long and continuous mountain belt.
What is an example of a convergent plate boundary
The Cascade Mountain Range, The Andes Mountain Range ,
Where are most of the world's active volcanoes?
The Ring of Fire
How do transformers work?
They step the potential difference up at one end for efficient transmission and then bring it back down again to safe, usable levels at the other end
What causes rock deformation?
Very HIGH amounts of PRESSURE (or stress)
ash fall
Volcanic ash falling through the air.
At an ocean/continent convergent boundary, what are the 2 things created? *
deep ocean trench in the water and volcanoes on the land
What are the three types of plate boundaries
divergent, convergent, transform
At a transform boundary, the plate movement causes? *
earthquakes
The fossilized plants that create coal deposits show that Antarctica was once near the ________.
equator
pyroclastic flow
fast moving avalanches of hot gas, ash, and rock
What is a primary wave
first, and fastest and least damaging earthquake
At a continent/continent convergent boundary, what is created? *
folded mountains
The _______ that moves the plates was found on the sea floor.
force
Scientists look at all of these factors to determine if a volcanic eruption may happen.
gas emissions, past history, earthquake activity, changes in shape
____ grooves on continents that currently have warm climates show that these continents once had cold climates.
glacial
What makes up the lithosphere
t The crust and the upper layer of the mantle together make up a zone of rigid, brittle rock called the Lithosphere .
How do tectonic plates move in relationship to the asthenosphere
tectonic Plates move over the asthenosphere
What is the difference between a focus and the epicenter
the epicenter is the location right above the earthquakes focus. The focus is where rocks first move along a fault
mud flow
the flow of a mass of mud or rock and soil mixed with a large amount of water
what happens When two plates collide
the less dense plate slides under the more dense plate
What is the epicenter of an earthquake?
the point on Earth's surface directly above the earthquake's focus
lava flow
the spread of lava as it pours out of a vent
Crust is neither destroyed nor created along a ___________ plate boundary.
transform
How do S waves cause partials to move?
up and down at right angles relative to the direction the wave travels
What do surface waves do?
They produce the most sever ground movements
Viscosity
A liquid's resistance to flowing
Richter scale
A scale that rates an earthquake's magnitude based on the size of its seismic waves.
What did the continental drift hypothesis state
Continents are in constant motion on earths surface, Earth was originally was made up of one large supercontinent called Pangaea, and Continents look like they could fit together like puzzle pieces.
basal drag
Convection currents in the mantle produce a force that causes motion
Where do volcanoes form?
Convergent (subduction) plate boundaries, divergent plate boundaries and over hotspots
Where do volcanoes form? Why? (c plate boundaries)
Convergent plate boundaries: Two plates collide, and the denser plate subducts into the mantle. The thermal energy below the surface and fluids that are driven off of the subducting plate melt the mantle and form magma. Magma is less dense than the mantle and rises through cracks in the crust, which forms a volcano.
How do tectonic plates move in relationship to the lithosphere
Earth's solid outer crust, the lithosphere, is separated into plates that move over the asthenosphere
what forms at transform plate boundary
Earthquakes occur and, of course, trust is broken but not destroyed
What does the theory of plate tectonics state
Earths surface is made up of ridged slabs of rock, or plates, that move with respect of one another Tectonic is the forces the shape Earths surface and rock structure
What was the name of one of the explorers who discovered either leaves and stems or beds of coal on Antarctica?
Ernest Shackleton
pyroclastic flow
Explosive volcanoes can produce fast-moving avalanches of hot gas, ash, and rock called this
Explain the two reasons why scientists doubted Wegener. What 2 things couldn't Wegener explain?
First, he didn't know the forces that caused continental drift. Second, the moving of the continents is a slow process, and he couldn't measure it.
What is a Normal fault
Forces pull two blocks of rock apart The block of rock above the fault moves down in relative to the block of rock below the fault
What is a Reverse faults
Forces push two blocks together and the rock above the fault moves up relative to the block below the fault,.
Explain how Glossopteris provides evidence of continental drift.
Fossils of the plant Glossopteris have been found on many different continents separated by oceans, including Antarctica. The plant couldn´t have traveled this distance. Also, it lived in a swampy climate, so this means Antarctica once had a warmer climate.
What where the climate clues that scientists found
Glacial grooves found on 4 warmer continents-South America, Africa, India, Australia, and Fossils that lived in a cretin climate where found in a place with the opposite climate the fossil once lived in
One specific plant, the. , has fossils in South America, Africa, India, Australia
Glossopteris
What where the fossil clues the the scientists found
Glossopters was found on 5 different continents including South america, Africa, India, Austria, and Antarctica. the seeds could have not traveled across oceans
Name the two "super" continents that Pangaea broke into as the continents began to move apart.
Gondwanaland & Eurasia
Magma with a high silica content has a .......viscosity
Higfh
High silica content - subduction zones and continental hot spots
High viscosity and flows like a sticky toothpaste
Where do volcanoes form? Why? (hs)
Hot spots: Not all volcanoes are near plate boundaries. Hot spots are not associated with plate boundaries and scientists hypothesize that hot spots originate above a rising convection current in the mantle. They use the word plume to describe rising currents of hot mantle material.
How do primary waves cause particles to move
In a push-pull motion
How do surface waves cause partials move?
In a rolling motion
When 2 oceanic plates collide a volcano is formed along the mid-ocean trench. These islands are called?
Island Arc
What does the ring of fire tell us
It tells up that most volcanoes form along plate boundaries
The deepest spot in the ocean is called the _________________.
Mariana's Trench
What forms at divergent boundaries?
Mid-ocean ridges (in the oceans) and Rift valleys (on continents)
magma
Molten rock below Earth's surface
Magma
Molten rock beneath the earth's surface
lava
Molten rock that erupts onto Earth's surface
What where the rock clues that the scientists found.
Mt. ranges and rock formations on different continents had common origins. Volcanic rocks on the Western coast of Africa and the Eastern coast of South America are identical in chemistry and age. The Caledonian mt range n Europe and the application range in North America are the same rock type, age and structure. When you connect them they line up perfectly and form one large belt across the two continents
Do the tectonic plates move in the same direction?
NO
Plants and animals wouldn't be able to travel across the large blanks that separate these continents, so this suggests that at one point in time these continents were either connected or at least
Oceans; closer together than they are now
What is the largest tectonic plate
Pacific Plate
Alfred Wegener believed that the Earth was originally made up of one large supercontinent called
Pangaea
What are the Three types of seismic waves
Primary waves Secondary waves Surface waves
Why did scientists reject Wegener's theory?
The contents move slowly so it was not something that could easy be seen or measured, and Wegener could not explain what forces caused the continents to move.
State Alfred Wegener's hypothesis.
The continental drift hypothesis states that the continents are in constant motion on Earth's surface.
How do volcanoes affect climate?
The gases and particles block/ reflect the sunlight and cool the atmosphere.
Mantle
The layer of hot, solid material between Earth's crust and core.
What can eventually happen during rock deformation
The rock changes shape
What is a secondary wave
The second wave that comes
Name two types of climate clues used by Wegener to support his hypothesis. Explain why they support continental drift.
There are glacial grooves in some continents that now have warm climates, which suggests that they must have cold climates. Another reason is Glossopteris lives in a swampy climate, but it was found in Antarctica, which mean Antarctica once had a warmer climate. This explains continental drift because it means the continents were closer to the equator of the South Pole, and were in different locations than today.
Explain how convection currents in the mantle work: where does the thermal energy come from? What happens to the material that is heated? What happens to the material as it gets near the crust?
Thermal energy comes from the core and then is transferred into the mantle. The warmer, less dense material rises and the cooler, more dense material sinks. This creates a circular motion. As it gets near the crust, the material cools down and that continues the circular motion.
Large and explosive volcanic eruptions can change climate because
ash and gas that erupt high into the atmosphere can reflect sunlight
Tectonic plates float on the ____________.
asthenosphere
What layer do the tectonic plates float on?
asthenosphere
What layer do the tectonic plates move on?
asthenosphere
How do divergent plates move?
away from each other
Glossopteris suggests that continents were blank together, and it also suggests that the blank of Antarctica was once warm and wetter, to be able to sustain this type of blank life.
closer; climate; plant
At an ocean/ocean convergent boundary what is created? *
island arc (volcanic arc of islands)
A ________ can also form where two oceanic plates collide.
line of volcanoes
The crust and upper mantle make up Earth's
lithosphere
Tectonic plates are pieces of the ________ that float on the more fluid ________ below.
lithosphere and Asthenosphere
Magma that has a low silica content has ____ viscosity
low
Magma with low silica content has a .... viscosity
low viscosity
At a divergent plate boundary such as a mid-ocean ridge, you should expect to find
low viscosity lava and normal faults
Volcanic ash and acid droplets in the atmosphere ___ Earth's temperature
lower
This is the molten mixture of rock forming substances, gases and water from the mantle.
magma
What determines the volcanoes eruption style?
magma chemistry
Convection currents in the _________ move tectonic plates.
mantle
ridge push
plates are pushed away from each other at mid-ocean ridges
Do tectonic plates move because of conduction current or convection currents?
r convection currents
When droplets of sulfuric acid from volcanoes form in the atmosphere, they ____ sunlight into space
reflect
At a continental/continental divergent boundary, what is created? *
rift valley
The release of a large amount of volcanic ash can affect Earth's climate by blocking ___
sunlight
a weak spot in the crust where magma comes to the surface is called:
volcano
(Glaciers don't form in these areas now because they have a. climate and they are closer to the equator)
warmer
Where do volcanoes form? Why? (d plate boundaries)
Divergent plate boundaries: Lava erupts at Divergent plate boundaries. Two plates spread apart and magma rises through the vent/opening in Earth's crust that forms between the plates. This commonly occurs at mid-ocean ridges and forms new oceanic crust.
Ash fall
During an explosive eruption, volcanoes can erupt large volumes of volcanic this. This is a mixture of particles of pulverized rock and glass.
What are the characteristics the mantel
the mantle is the mostly-solid it lies between Earth's core and the crust
Lithosphere
the solid, outer layer of the earth that consists of the crust and the rigid upper part of the mantle
Asthenosphere
the upper layer of the earth's mantle, below the lithosphere and where the lithosphere floats
What is volcanic ash?
tiny particles of volcanic rock and glass
How do convergent boundaries move?
towards each other
