Exam- Plate Tectonics Flashcards
Evidence that supports plate tectonic theory
- same fossil on other sides of the ocean
- same rock on other sides of ocean
- continents fit together like puzzle pieces
- glacial evidence in Africa
- magnetic reversals on the mid-Atlantic ridge
Dip in the ocean floor formed from subduction
Trench
Longest mountain chain in the world formed at divergent boundary
Mid-ocean ridge
Formed when India converged with Asia
Himalaya mountains
Type of boundary when plates pulled apart
Divergent
Space created when plates pull apart
Rift Valley
Cycle of magma in the mantle which makes the plates move
Convection current
Island located on the mid-ocean ridge in the Atlantic Ocean
Iceland
When 2 plates slide past each day other
Transform fault
When 2 plates collide and 1 goes under
Subduction
Plate Tectonic Therory
Theory that the earth’s lithosphere is broken into large sections called plates. Plates move due to convection currents in the earth’s mantle
This part of Africa is pulling apart and will one day be a sea
Great Rift Valley
Giant sea wave formed in a subduction zone
Tsunami
Lithosphere plates move due to:
Convection
The Ring of Fire is a major volcanic belt around the
Pacific Ocean
In general how fast to the plates move
Centimeters per year
What feature forms at an ocean-ocean subduction zone?
Volcanic islands and trenches
Glacial evidence near the equator in Africa indicated to Wegener that this continent was:
Once located closer to the South Pole
Which process creates as many as 30 small earthquakes daily in California
Transform Fault
Generally, what is the age of the oceanic crust?
Younger than the continent crust
What was Wegener’s hypothesis called?
Continental Drift
What wasn’t used in Wegener’s hypothesis?
Magnetic reversals
Evidence that support Wegener’s idea of a supercontinent called Pangea include:
- Continent coastlines match
- Fossil evidence
- rock types match on adjacent continents
What type of plate boundary represents a trench forming
Convergent subduction
Amount of energy released by an earthquake
Magnitude
Amount of energy measured by a logarithmic scale
Richter Scale
The amount of damage from an earthquake
Intensity
Natural disasters that an earthquake could cause
- Landslide
- tsunami
Earthquake waves are measured using a_________________?
Seismograph
What type of waves does the seismograph record?
P,S, and L waves
The difference in arrival time between the p and S waves is called
Lag time
Lag time is helped used to determine the location of the
Epicenter
What can volcanoes form on that is not a plate boundary
A hotspot
Examples of convergent subduction
- Mariana’s Trench
- Mt. St. Helens
- Japan
- Andes Mtns
- Aleutians Islands
Example of transform fault
San Andreas Fault
Examples of divergent boundary
- Iceland
- Great Rift Valley
- Mid Ocean Ridge
Examples of convergent collision
Himalayas
Point on the earth’s surface directly above focus
Epicenter
Actual spot in the crust where the earthquake occurred
Focus
What are the three types of faults
Strike split
Thrust
Normal
Total force acting on crustal rock per unit area
Stress
Deformations of material caused by stress
Strain
A material is compressed, stretched, or bent, but returns to its original shape when stress is removed
Elastic deformation
A material is compressed, stretched, or bent, but stays deformed when stress is removed
Plastic deformation
Where are most faults located
Plate boundaries
A break or crack in the crust
Cause of earthquakes
Fault
P wave
- Primary wave
- Push waves
- travel the fastest
- travel through any material
S wave
- secondary wave
- snake waves
- travel 2nd fastest
- doesn’t travel though liquids
L wave
- surface waves
- cause most damage
What is ground shaking multiplied by
Power of 10
What is total energy multiplied by
Power of 32
What are the three causes/locations of volcanoes
- Hot spot volcano
- Rift volcano
- Subduction volcano
High temperature lava has _________ silica and flows ________
Low
More/easily
Low temperature lava has __________ silica content and flows________
High
Slowly
A high silica example is
Rhyolite
A low silica example is
Basalt
String of volcanoes in a subduction zone
Island arc
Earthquakes happen at these plate boundaries
All
Three volcano cone types
Cinder
Shield
Composite/Statovolcano
A cinder volcano has a _________ slope
A shield volcano has a _________ slope
A composite volcano has a _________ slope
Steep
Gentle
Intermediate
Example of cinder is
Paracutin
An example of shield
Mauna loa
An example of composite is
Mt. St. Helens
Cinder has ________ silica content
Lava description is ______________
High
Thick
Shield has ________ silica content
Lava description is ______________
Low
Thin
Composite has ________ silica content
Lava description is ______________
Medium
Both thick and thin
What on a composite volcanos makes the volcano have layers
The repeated eruptions
What type of volcano has a lot of cinder and ash
Composite volcano
What direction does a dike form
Upwards
What direction does a sill form
Horizontally
Why does intensity differ
Because of the magnitude
On the Richter scale the _________ goes up a power of ____ for each number you go up
- Magnitude
- 10
How fast do plates move per year
Centimeters
The underground point of origin is called the
Focus
The damage from earthquake depends on
Location of the earthquake types of buildings in the area and type of soil in the area
Where is maximum earthquake intensity usually found at
Epicenter
What earthquake waves is most similar to ocean waves
L wave
What earthquake waves only travel along the surface
L waves
What earthquake waves help us understand the inside of earth must’ve been a liquid outer core
S waves
The tube that connects the magma chamber to the creator of a volcano is the
Vent
High silica content found them lava results in
Thick slow lava flow
Shield cone
Gentle slope
Thin lava
Mauna loa Hawaii
Cinder cone
Steep slope
Thick ash and lava
Paracutin Mexico
Composite cone
Intermediate slope
Alternating thick and thin lava
Mt St. Helens
