Chapter 25 Flashcards
The MOR system in the Atlantic ocean,called the Mid-Atlantic Ridge
mid-ocean ridge
A long narrow depression forms in between peaks along the mid-ocean ridge.
rift valley
the boundary where two plates collide
convergent plate boundary
the point of origin for an earthquake
focus
when a thick and buoyant continental plate meets a thin and dense oceanic plate the denser plate dives beneath the continent
subduction
divergent plate boundary
the boundary between two plates that are moving apart
this type of boundary where plates slide horizontally past each other in opposite directions
transform plate boundary
the sudden movement or vibration of the ground that occurs when rocks slip and slide along enormous cracks in Earth’s crust called faults.
earthquake
a crack in Earth’s crust strain energy builds up in the rock has moves
fault
the sudden release of strain energy as rock moves along a fault
elastic rebound
the point on Earth’s surface directly above the focus
epicenter
who came up with the continental drift hypothesis?
Alfred Wegener
what where some pieces that supported his hypothesis ?
1,coastline matched like puzzle piece
- he looked at large land animal fossils
- mountain ranges matched up had similar rock type and age
what was the name of the super cont
Pangaea
who came up with the Seafloor spreading Hypothesis?
Harry Hess
What did he use to come up with the Seafloor spreading hypothesis?
sonar
Who discovered the Mid-Ocean ridge?
Harry Hess
where can we find the youngest rock on the seafloor?
close to the MOR
what are the three of the plate boundaries?
convergent
divergent
transform
what are the two type of crust that deal with in class
oceanic crust
continental crust
How do convergent plates boundaries move?
collide together
what land forms are created when ocean crust and continental crust converged?
volcanoes
deep sea trench
subuduction happen with which type of boundary?
convergent
what type of land forms when two oceanic crust come together?
deep sea trench
hot sports which create lands
what type of land forms are created when two continental come together?
Mountains
what kind of crust must be present for Volcanic activity to occur?
oceanic crust
How do divergent plates move?
they divide/ move away from each other
what are specific example of a divergent plate boundaries?
MOR ( both are oceanic crust )
East African Rift ( both continental)
how do transform plates move?
slide pasted each other
what a specific example of a transform plate boundaries?
San Andreas fault ( both continental)
what is a convection current?
- Magma heats up , becomes less dense and rise
2. Magma cools down, becomes more dense and sinks
what are other forces that help plates in motion?
slab pull
ridge push
and friction
which type of plate boundaries have shallow earthquakes?
divergent
transform
which plate boundaries have deep earthquakes?
convergent
what type of stress can be applied to rocks to cause movement?
compression stress
tension stress
shear stress
torsion stress
what are the types of deformation that can be cause do to stress?
Elastic
plastic
what happens to a material when elastic deformation happens?
deforms then snaps back in place
what happens to a material when plastic deformation happens?
deforms then changes into a new shape
how many types of seismic waves are there?
1 primary waves
2 secondary waves
3 surface waves
which waves are the fastest wave ?
primary waves
what type of wave is the p-waves?
a compression wave
what type of materials can a p wave travel through?
solid
liquid
what type of wave is a secondary wave ?
transverse
what type of of materials can a s -wave travel through?
solid
which wave is the most complex and damaging?
surface waves
what are the names of the measurement we use to measure earthquakes?
Richter scale
Mercalli scale
what does the Richter scale measure about an earthquake?
the amount of energy released
what dose the Mercalli measure in an earthquake?
the amount of damage that was caused
