chapter 2 Flashcards
old crust is preserved at what type of boundary?
f
____ was the oldest known location technique on the globe that required only the stars while ____ needed an accurate timepiece to plot accurately
latitude/longitude
the himalaya are an example of the tectonic force of a
continent-continent convergent collision
plate tectonic theory
Alfred Wegner
late 1960s adopted
the continents were all once connected and have drifted apart
continental drift theory evidence
fossils, cross atlantic mountain belts, similar rock units, glaciations
why are earthquakes found mainly at the edges of plates
breakage and deformation of the lithosphere is focused at plate edges
p-wave
primary wave highest velocity particle compression can pass through liquid and solid travel furthest from epicenter
s-wave
shear wave
second fastest
vertical particle motion
can pass through solid but not liquid
surface waves
slowest but most destructive
reyleigh waves and love waves
reyleigh waves
up and down motion
love waves
lateral motion
divergent plate boundaries
new crust created at mid ocean ridges
volcanoes
convergent plate boundaries
crust subducted and remelted
volcanoes and large earthquakes
transform plate boundaries
plates sliding past each other earthquakes do not create or destroy crust can be on continent or in ocean connect spreading centers (divergent boundaries) ex) san andreas fault, CA
passive margin
edges of the divergent basin
oceanic rise
fast spreading
gentle slopes
east pacific
oceanic ridge
slow spreading
steep slopes
mid atlantic
ultraslow
deep rift valley
widely scattered volcanoes
arctic and southwest india
ocean-continent convergent plate boundaries
ex) andes mountains, w South America
Ocean-ocean convergent plate boundaries
ex) Japanese volcanic islands
Continent-continent convergent plate boundaries
ex) Himalayas, india asia collision
The Strongest earthquakes occur
at convergent boundaries
Wilson cycles
tectonic cycles over geologic time scales of ocean basin creation growth closure and destruction
Wilson cycles: embryonic
uplift
complex system of linear rift valleys on continent
east african rift valleys
Wilson cycles: Juvenile
Divergence
narrow seas with matching coasts
red sea
Wilson cycles: Mature
divergence
ocean basin with continental margins
atlantic and arctic oceans
Wilson cycles: Declining
Convergence (Subduction)
island arcs and trenches around basin edge
pacific ocean
Wilson cycles: Terminal
convergence (collision) and uplift
narrow irregular seas with young mountains
mediterranean sea
Wilson cycles: Suturing
convergence and uplift
young to mature mountain belts
himalaya mountains
