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Which of Earth's layers is liquid? - Ans✔✔-outer core
Which of Earth's layers is solid? - Ans✔✔-crust, inner core, mantle
what is the Earth's core made out of? - Ans✔✔-iron and nickel
what is the mantle made out of? - Ans✔✔-iron and magnesium silicates
density of the mantle - Ans✔✔-less dense
density of the crust - Ans✔✔-least dense
is the mantle rigid? - Ans✔✔-yes
asthenosphere - Ans✔✔-plastic-like layer in the mantle
,what is in the crust? - Ans✔✔-silicates, potassium, sodium
what makes up the lithosphere? - Ans✔✔-crust and upper mantle
how thick is the lithosphere? - Ans✔✔-50-200km
what are tectonic plates? - Ans✔✔-blocks of lithosphere floating on the
asthenosphere
who proposed the continental drift hyphothesis? - Ans✔✔-Alfred Wegener
what was Wegener's evidence? - Ans✔✔--The map fit together
-Mountains, continents, and rocks all match
-Fossils were distributed across borders and certain species were found on
multiple continents
-Glaciers leave specific marks that have directionality
what are the two types of crust? - Ans✔✔-oceanic and continental
Why did scientists reject Wegener's theory? - Ans✔✔--he was a meteorologist
-had no hypothesis for driving forces
-the best geologists lived in the northern hemisphere but best evidence was in
the southern hemisphere
,modern evidence for plate tectonics - Ans✔✔-paleomagnetism, magnetic
striping, age of seafloor, GPS tracking of plate movements, plate velocities and
vectors, earthquakes at subduction zones
how is paleomagnetism evidence for plate tectonics - Ans✔✔-prehistoric
Earth's magnetic fields recorded in rocks, sediment, or archeological materials
how is magnetic striping evidence for plate tectonics - Ans✔✔-Changes in
magnetic polarity recorded in rocks that cool from lava
how is age of seafloor evidence for plate tectonics - Ans✔✔-Oldest oceanic
crusts are the farthest from the tectonic plate lines
how is GPS tracking of plate movements evidence for plate tectonics - Ans✔✔-
Shows absolute movement in three dimensions
divergent boundary - Ans✔✔-two plates move away from each other
features of a divergent boundary - Ans✔✔-mostly undersea, lots of shallow
earthquakes, underwater volcanoes
what's different about the structure of divergent boundaries? - Ans✔✔-
symmetrical and can't curve or bend
convergent boundary - Ans✔✔-two plates move towards each other
which plate goes towards the core (ocean/ocean) - Ans✔✔-more dense plate
, how do trenches form - Ans✔✔-when oceanic plates are subducted under the
continental plate
how does density of plates relate to their age - Ans✔✔-Older plates are colder,
and colder plates are more dense
what happens if both plates are continental - Ans✔✔-they can't subduct and
crash into each other, forming mountains
transform boundary - Ans✔✔-plates slide past each other
passive margins - Ans✔✔-Continent connected to ocean with no movement,
thick layers of sediment on the ocean side
active margins - Ans✔✔-lithospheric plates move relative to each other
features of convergent boundaries - Ans✔✔-Volcanoes, earthquakes, and
mountain ranges
features of transform boundaries - Ans✔✔-small-medium earthquakes, no
volcanoes
convection in the mantle feeds volcanic activity at _ and _ - Ans✔✔-divergent
margins and hotspots