unit 7 plate tectonics vocabulary

45 terms :')

abrasion

a way rocks are weathered by winds blowing sand against rock, or ice in a glacier rubbing against rock

acid precipitation

rain that is more acidic than usual and speeds up the weathering process

asthenosphere

the layer immediately below the lithosphere that is made of rock that can flow

chemical weathering

involves a change in the chemistry of rocks

compression

the stress that squeezes or shortens material, can cause folds

continental drift

the hypothesis that today’s continents were once part of a single landmass

contour interval

the difference in elevation between the two contour lines

contour line

lines that connect points of equal elevation

convergent boundary

a boundary where two tectonic plates collide

deformation

the bending, tilting, and breaking of rock

delta

a fan shaped mass where streams enter the ocean

deposition

lays down rock, sediment, and soil

divergent boundary

a boundary where two tectonic plates move away from each other

erosion

transports rock, sediment, and soil from one place to another

exfoliation

buried rock is exposed to the earth’s surface and the top layer flakes off due to the release of pressure

faults

where the rock breaks

folds

where the rock bends, but does not break

glaciers

large mass of ice that exists year round and flows slowly over land

ice wedging

when water seeps into a crack in a rock, freezes and expands to make the crack larger

index contour

every fifth contour line on a topographic map that often has an elevation label

lithosphere

the outermost layer of the earth

magnetic reversals

a change or switch of magnetic poles

mid-ocean range

a string of connected volcanic mountains formed on the ocean floor; formed by magma rising at a divergent boundary

oxidation

certain elements in rocks combine with oxygen in the air or water to form chemical compounds

physical weathering

also called mechanical weathering where rocks are physically broken down into smaller pieces

plate tectonics

states that earth’s surface is made of giant slabs called tectonic plates

relief

the difference between the highest and lowest elevations in a particular area

ridge push

possibly a driving force behind plate tectonics, where oceanic plates slide downhill due to gravity

rifting

the process by which earth’s lithosphere pulls apart to form long narrow, faulted rift valleys

scale

to show the relationship between the sizes and distances shown on a map

sea floor spreading

the process by which new seafloor is created

sediment

weathered rock pieces

shear stress

the stress that causes material to twist or become distorted

slab pull

possibly a driving force behind plate tectonics; where oceanic plates sink into the asthenosphere at subduction zones

slope

measures steepness from one point to another

stress

the amount of force per area put on a body

subduction

the process by which one tectonic plate is pulled beneath another plate

tectonic plate

the large moving pieces of the lithosphere

tectonic setting

description of what two plates are involved and what direction they are pulling

tension

the stress that lengthens material or pulls material apart

theory

a system of ideas that explains many related observations about the natural world

topographic map

shows the shape of earth’s surface with lines that represent different elevations

topography

the shape and size of the land features on earth

transform boundary

a boundary where two tectonic plates move past one another in opposite directions

weathering

the process by which rocks break down into smaller pieces