2: plate tectonics Flashcards
who outlined the continental drift hypothesis and supercontinent (Pangea) theory?
Alfred wegener
what idea did the continental drift challenge?
that the earth’s continents and ocean basins had fixed geographic positions
oceanic crust is composed of
basaltic rock
continental crust is composed of
granitic rock
what does asthenos mean in asthenosphere
weak
what does lithos mean in lithosphere
stone
the plates of the earth are apart of the
lithosphere
the longest topographic feature on earth is
the global oceanic ridge system
convergent boundaries are also called
subduction zones
deep ocean trenches are produced from
convergent boundaries/subduction zones
what is a mantle plume
a cylindrical upwelling of hot rock originating from the mantle
how did we confirm the ocean floor’s youngest at the ridge axis?
deep sea drilling
what is a hot spot
an area of volcanism, high heat flow, crustal uplift measuring some kilos across
what are hot spots general position
relatively fixed within the mantle
if a plate moves over a hot spot, what is created?
a hot spot track
an example of a hot spot track
hawaii
the threshold temperature for magnetism
curie point
how is plate motion measured?
by ocean drilling, researchers obtain dates for all locations on the sea floor
the way heat transfers through liquids and gases
convection
what is slab pull?
subduction of slabs of oceanic lithosphere
why does slab pull happen?
the oceanic lithospheric slabs are much denser than the underlying asthenosphere, so the labs are weighted and pulled down by gravity
what is the driving force of plate motion?
slab pull and ridge push
What is the process that occurs along oceanic ridges where newly formed oceanic lithosphere is being pushed away from the ridge axis?
ridge push
