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stress

the amount of force placed on a given material

deformation

the process by which the shape of a rock changes because of stress

compression

when stress squeezes an object

large mountain ranges

can form when compression squeezes rocks at a convergent place boundary

folding

the bending of rock layers due to stress

monocline

a fold where both ends of the rock layer are horizontal

syncline

a downward, trough-like fold

anticline

an upward-arching fold in a rock layer

fault

when rock layers break, the resulting surface they break and slide

normal fault

when tension pulls rocks apart, this is created

reverse fault

when compression pushes rocks together this is created; the hanging wall moves up relative to the hanging wall

strike-slip fault

when opposing forces cause rock to break and move horizontally this is created; related to transform boundaries

foot wall

when a fault is not vertical, a hanging wall and this are formed

normal fault

the hanging wall moves down relative to the foot wall in this; the tension pulls the fault apart (divergent)

mountain ranges

when tectonic plates collide, folds and faults can become these

folded mountains

this kid of mountain range is formed when rock layers are squeezed and forced upward; Appalachian, Himalyas and the Alps

fault-block mountains

this kind of mountain range is formed when tension causes large blocks of crust to drop down; like Sierra Nevada and Teton range

volcanic mountains

form when convergent oceanic crust sinks into the asthenosphere. The crust melts, forms magma and erupts

Appalachian Mountains

folded mountains

Tetons

fault-block mountains

Ring of Fire

volcanic mountains

uplift

the rising of Earth's crust to higher elevations

subsidence

the sinking of regions of the Earth's crust to lower elevations

rebound

when the Earth's crust slowly springs back to its original elevation

subsides

this is what happens to the ocean floor the farther the oceanic lithosphere is from a mid-ocean ridge

rift zone

a set of cracks that from when two tectonic plates are pulling away from each other

compound

a substance composed of two or more elements

gravity

the reason less dense compounds make up Earth's crust while the densest compounds make up the core

crust

the outermost layer of the earth

mantle

the "middle" layer of the earth

core

the innermost layer of the earth

oxygen, silicone, aluminum

three elements that make up most of the earth's crust

iron, calcium, magnesium

oceanic crust is denser than the continental crust because it contains more of these three elements

magnesium

the mantle is composed of more of this element than the crust is.

ocean floor

where scientists look for clues about the mantle (because magma flows out of volcanoes there and there is more magnesium in the mantle, making it denser)

aluminum and silicone

the mantle has less of these elements than the crust

iron

this element makes up most of the earth's core

one third

this much of the earth's mass is made up by the core

lithosphere

the outermost, rigid layer of the earth

asthenosphere

a layer of slowly flowing rock in the mantle

outer core

the liquid layer of the core

inner core

the solid layer of the core

mesosphere

the strong, lower part of the mantle

tectonic plates

large pieces of the lithosphere that move around on the asthenosphere

jigsaw puzzle

tectonic plates fit together like this

continental, oceanic

two kinds of crust that a tectonic plate may contain

float and cover the surface, touch and move around, displace

ways in which tectonic plates floating on the asthenosphere are similar to ice cubes filling a punch bowl

seismic waves

vibrations from an earthquake; what scientists use to study earth's interior

continental drift

the hypothesis that Alfred Wegener used to explain why continents seem to fit together

one

according to wegener how many landmasses did all continents once form?

Wegener's hypothesis about the continents

they broke up and drifted to their current locations

pangea

Wegener's name for all of the present continents that he thought were once joined 245 million yr ago in a landmass

Laurasia, Gondwana

when the single landmass split into 2 huge continents about 180 million yr ago, Wegener call the countries these names

continents today

when the two continents split 65 million years ago, Wegener said this was formed

lack of evidence

the reason that many scientists rejected Wegener's hypothesis for the separation of the continents

crust is formed

this happens in the process of sea-floor spreading when magma rises to the earth's surface and solidifies

sea-floor spreading

process of forming new oceanic lithosphere as magma rises to the surface

mid-ocean ridges

areas where sea-floor spreading takes place

magnetic reversal

process that happens when earth's magnetic poles change place

continental drift

theory that explains how continents reached their current locations

magnetic reversal

rock on the ocean floor provided the final prof of sea-floor spreading with a record of this

Plate Tectonics

the theory that earth is divided into plates that move around

tectonic boundary

the place where tectonic plates touch is known as this

fault-block boundary

NOT a type of tectonic plate boundary

collide, separate, and slide

three ways that tectonic plates can move relative to each other

convergent boundary

boundary formed when tectonic plates collide

divergent boundary

boundary formed when tectonic plates separate

transform boundary

boundary formed when tectonic plates slide past horizontally

transform boundaries

this type of boundary produces earthquakes

rise

this happens when a rock is heated and becomes less dense

sink below the surface

this happens when rock cools and becomes more dense

gravitational energy

density changes in the asthenosphere are cause by the floor of this deep within the earth

slab pull

plate motion due to higher densities

ridge push

plate motion due to gravity

convection

plate motion due to the heating and cooling of rocks

centimeters per year

this is how fast tectonic plates move

global positioning system

this is what scientists use to measure the rate of tectonic plate movement

tension, compression

two types of stress that can be applied to the rock

mountains ranges

these are formed at convergent boundaries when compression occurs

tension

this happens at divergent boundaries

anticline

upward arches (frowny)

suncline

downward arches (smiley)

monocline

the rock folds so that both ends are horizontal

hanging wall

a fault block that you would "hang from"

strike slip fault

can form folded, fault block and volcanic mountains

folded mountains

the highest mountains in the world; they form at convergent boundaries where continents have collided

Mariano Trench

the deepest known place on earth; approx. 7 miles deeper than sea level

boundaries

where the tectonic plates touch

convergent, divergent and transform

types of boundaries

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