chapter 25 Flashcards
sudden movement or vibration of the ground that occurs when rocks slip and slide along enormous cracks in the earth’s crust called faults.
Earthquake
a system of mountain range on the ocean floor separated by valleys.
Mid-ocean-ridge
a long narrow depression formed between peaks along the mid-ocean-ridge
rift valley
boundary where two plates collide
converting plate boundary
the denser plate dives beneath the continent
subduction
boundary between two plates moving apart
divergent plate boundary
slide horizontally in opposite directions.
transform plate boundary
a crack in the earths surface
fault
sudden release of tension wile rocks slide along
elastic rebound
the point of oragin of an earthquake
focus
earth above the focaus
epicenter
Who came up with the continental drift hypothesis?
Alfrid Wegener
What was some evidence did Wegener find to support his hypotheses.
1 large land animal fossle
2 coast lines matched up
3 mountain ranges matched up with same rock type and ages
what was the name if the supper continent?
Pangaea
Who came up with the seafloor spreading hypothesis?
Harry Hess
How did he discover seafloor spreading?
using sonar
What did hess discover?
The mid-ocean-ridge
What are the 3 types of plate boundaries?
1 divergent
2 convergent
3 transform
how do convergent faults collide
to toward each other\into each other
subducton zones only happen with witch type of plate boundary
convergent
what 2 types of crust are there?
oceanic
continental
What can be formed when a oceanic crust and a continental crust converge.
volcano
trenches
what can form when 2 oceanic crusts converge
beep sea trench
hot spots volcanic islands.
what land formed are created when 2 Continental crusts converge.
mountains
what type of crust must be present for c=volcanic activity to ocure
oceacic
How do divergent plates move?
away from each other/ away from
What are some examples if divergent plats
1 MOR- 2 oceanic
2 East African Rift - 2 Continental
How do transform plates move?
slide along each other (only one)
what is an example of a transforming plate boundary
San Andreas fault - 2 Continental
What is a convection current?
- magma heats up, become less dense, and rises
2. magma cools and becomes more dense and sinks.
what are three forces that contribute to plate motion
1 slab pull
2 ridge push
3 friction between plates
Witch plate boundaries has shallow earthquakes?
Divergent and Transform
Witch plate boundary has deep earthquakes.
Convergent
What are the types of stress that can be applied to rock movement.
Compression
tension
sheer
torsion
compression, tension, sheer, torsion
push together, pull, slide along, twist
what are the 2 types of deformation.
elastic
plastic
what happens when elastic deformation happens
materiel goes back to original state
what happens when plastic deformation occurs
takes on a new shape
how many types of seismic waves are there
3
primary- p waves
secondary- s waves
surface waves
what type of seismic waves are the fastest
primary/ p-wave compression wave
what type of wave is a p-wave
compression wave
what type of material can p-waves go through
solids and liquids
What type of wave is a s-wave
transverse wave
what type of materials can a s-wave pass through
only solids
witch wave dose the most damage
surface waves
what are the 2 scales that measure earthquakes
Richter scale
mercalli scale
what dose the richter scale measure
the amount of energy released
what dose the mercalli scale measure?
the amount of damage.
