plate tectonics

convergent boundaries (direction and what they create)

-plates moving towards each other

-creates trenches, volcanoes, mountains, and islands

divergent boundaries (direction and what they create)

-plates moving away from each other

-creates new crust, mid ocean ridges, volcanoes, and rift valleys

transform boundaries (direction and what they create)

-plates sliding past each other

-causes earthquakes & faults

convection current

-drives the movement of plates

-Convection moves plates in the mantle because rocks that are hot enough to bend easily are pushed to the surface before sinking back down. When less dense mantle rises, it pushes plates along at mid-ocean ridges, which pulls the plates at convergent boundaries

-drives plate movement in the mantle of the earth

-the circulation within fluids caused by differences in density and thermal energy

-at divergent plate boundaries (like mid-ocean ridges), rising currents pull plates apart

- at convergent boundaries (like subduction zones), sinking currents pull a plate back into the mantle. 

mantle

-place where convection occurs

convergent boundaries continental-continental 

-denser older material subducts

-creates (folded mountain range)

convergent boundaries continental-oceanic

-oceanic subducts because it is more dense

-creates ocean trench & volcanic mountain arcs

convergent boundaries oceanic-oceanic

-denser older material subducts

-creates ocean trench & volcanic island arc

transform boundaries oceanic-oceanic

-creates tsunami

subduction

-to go below

-occurs at trenches

-causes plate movement when two plates collide and ice subjects into the hotter and less dense mantle and the rest of the plate is pulled behind the sinking plate

plate techtonics

-the theory that earth is broken into plates and are in motion due to convection currents in the asthenosphere (upper mantle)

-crust

-thin & solid

-outermost layer of Earth

-above mantle

lithosphere

-solid (hard rock)

-outer layer of the Earth that contains the crust and upper mantle

-crust is entirely contained within the lithosphere

seafloor spreading

-process by which new oceanic crust forms as magma rises towards the surface and solidifies at divergent boundaries

-occurs at mid-ocean ridges

trench

-extremely deep valley formed at a subduction zone

-created by convergent boundaries

mid-ocean ridge

-underwater mountain range made at divergent plate boundaries where new crust rises

(3 pieces of) evidence Earth is made of moving tectonic plates

-fossils found on variety of continents (at coastlines that match up like Africa and South America

-location of earthquakes and volcanoes

-mountain ranges and rock layers match up

reason why magma rises in mantle

-rising magma is less dense

outer core

-liquid layer of Earth’s imterior

Earth’s mechanical layers

-lithosphere

-asthenosphere

magma

-what Earth is mostly made out of

-molten rock found beneath the Earth's surface, composed of a mixture of melted minerals and dissolved gases

continental crust vs oceanic crust

-oceanic crust = denser & thinner

-result = oceanic crust tends to subduct (slide beneath) continental crust at tectonic plate boundaries

Earth’s 4 major layers in order

-crust, mantle, outer core, inner core

mountains

-formed at convergent boundaries

volcanoes

-formed at both convergent and divergent boundaries

earthquakes

-mainly transform

-convergent and divergent

rift valley

-formed at divergent boundaries

-two pieces of land separated by a ridge