chapter 25 Flashcards
mid ocean ridge
a system of mountain ranges with a rift valley between them that extends around earth on the seafloor formed where oceanic plates spread apart due to magma rising.
rift valley
long narrow depression formed in between the peaks along the mid oceanic ridged.
convergent plate boundry
boundary where two plated collide produces either subduction zones or continental.
subduction
the movement of a dense oceanic plate under a buoyant continental plate.
divergent plate boundary
the boundary between two plates that are moving apart.
transform plate boundary
tectonic plate boundary in which plates slide horizontally past each other in opposite directions.
earthquake
sudden movement or vibration of the ground
fault
a crack in earths crust along which rock has moved
fault
a crack in earths crust along which rock has moved
focus
the point orgin for an earthquake
epicenter
the point on earths surface directly above the focus
who came up with the continental drift?
Alfred wegener
what are some evidence for the continental drift hypothisis?
1.The cost lines matched up
2. Mountain ranges matched up with same type
3
whats the name of super continent
pangaea
who came up with seafloor spreading hypothesis
harry hess
how did harry discover seafloor spreading
he discovered mid ocean ridge
who discovered MOR
harry hess
where are younger rocks formed
what are the type plate boundary
divergent boundary
convergent boundary
transform boundary
how do convergent plate boundarys move
collides
subduction only happens with with which type of plate boundary
convergent
what type of crust do we have
continental crust
which type of crust has to be present for volcanic activity
oceanic crust
what two lands can be created
valcanos deep sea trench
what can be created when two oceanic plates come together
volcanic islands
which plate boundaries have shallow earthquakes?
divergent and transform
what types of stress are applies to rocks that cause earthquakes
elastic and plastic
how many types of seismic waves are there
primary surface
