chapter 25 Flashcards
system of mountain ranges on the seafloor separated by valleys
mid-ocean ridge
a long narrow depression in between peaks
rift valley
the boundary where two plates collide
convergent plate boundary
the denser plate dives beneath the continent
subduction
the boundary between 2 plates that are moving apart
divergent plate boundary
plates slide horizontally past each other transform plate boundary
transform plate boundary
the sudden movement or vibration of the ground
earthquake
fault a crack in earth’s crust along which rock has moved
fault
strain energy and moves along a fault
elastic rebound
focus the point of origin for an earthquake
focus
the point on Earth’s surface directly above the focus
epicenter
Who came up with the continental hypothosis
Alfred Wegener
What are the 3 types of plate-boundaries
convergent, divergent, transform
Who came up with seafloor spreading
Harry Hess
What evidence did he find to back up his hypothesis
Large animal fossils, coast lines matched up like puzzle pieces, mountain ranged matched up with the same rock type and ages
How did he discover seafloor spreading
sonar
What did Hess discover using sonar
mid-ocean ridge
What was the name of the Super Continent
Pangaea
How do convergent boundaries move
come together and converge
Subduction zones only happen with which type of plate boundary
convergent plate boundary
What two types of crust are used for plate boundary
oceanic and continental
What landforms can be created
volcanoes
What two types of land forms can form when 2 oceanic crusts converge
hot spots that create chain isalands, deep sea trenches
what type of landforms are created when two continental converge
mountains
what type of crust must be present for volcanic activity to accure
oceanic
How do divergent plate boundaries move
They move apart
What are some examples of divergent plate boundaries
MOR “oceanic crust”
2. East African Rift
How do transform plate boundaries move
They slide horizontally past each other
What is a specific example of a transform plate boundary
San Andreas Fault
Continental Crust
What is a convection current
- Magma heats up, becomes less dense and rises.
2. Magma cools and becomes more dense and sinks.
Which plate boundaries have shallow earthquakes
divergent and transform
Which plate boundary has deep earthquakes
convergent
What are the types of stress that can be applied to rocks to cause them to move
compression
tension
shear
torsion
what are the 2 types of deformation
elastic
plastic
what happens to the rock or material when elastic deformation happens
the material goes back to its original shape
what happens to the material when plastic deformation happens
it takes on a new shape
how many types of seismic waves are there
primary waves
secondary waves
surface waves
what type of seismic wave is the fastest
p waves (primary wave)
what type of wave is a primary wave
compression wave
what type of materials can p waves pass through
solids and liquids
what type of wave is an s wave
transverse
which wave does the most damage
surface waves
what are the two scales that measure earthquakes
richter
mercalli
what does the richter scale about an earthquake
amount of energy relase
what does the mercally scale about an earthquake
