layers of the earth
one
according to Wegener, how many landmasses did the continents once form
anticline
an upward-arching fold in a rock layer
thermal
density changes in the asthenosphere are caused by the flow of __________________ energy from deep within the earth
Tetons
fault-block mountains
Appalachian mountains
folded mountains
constructive
forces that create deposition,
destructive
forces that destroy weathering and erosion
the same fossils were found on different continents that once fit together
how does fossil evidence support Wegener's theory
centimeters per year
how fast do tectonic plates move?
33%
how much of the earth's mass is made up by the core
tectonic plates
large pieces of the lithosphere that move around on the asthenosphere
Oceanic crust
less dense and made of basalt
they cover the surface, bump into each other, and displace the punch
list three ways in which a tectonic plates floating on the asthenospere are similar to ice cubes filling a punch bowl
mantle
located below the crust it is the largest layer-2900 km thick made up of magnesium and iron density increases with depth divided into three parts
core
located below the mantle divided into two layers densest layer
Continental crust
more dense and made of granite
crust
outermost, thinnest, least dense layer on the earth can be 5-70 km thick it is made of silicon, oxygen, and aluminum
ridge push
plate motion due to gravity
slab pull
plate motion due to higher densities
convection
plate motion due to the heating and cooling of rocks
seismic waves
scientists use _____________ to study earth's interior
compression
stress that occurs when forces act to squeeze an object
tension
stress that occurs when forces act to stretch an object
stress
the amount of force placed on a given material
folding
the bending of rock layers due to stress
convergent boundary
the boundary between tectonic plates that are colliding
transform boundary
the boundary between tectonic plates that are sliding past each other horizontally
divergent boundary
the boundary between two tectonic plates that are moving away from each other
uplift
the elevation of regions of the Earth's crust
continental drift
the hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present locations
outer core
the liquid layer of the core it is liquid made of mostly iron (easily magnetized) 2300 km thick
lithosphere
the outermost, rigid layer of the earth is made of the crust and upper mantle
tectonic boundary
the place where tectonic plates touch
sea-floor spreading
the process by which new oceanic lithosphere (sea floor) forms as magma rises to Earth's surface and solidifies at a mid-ocean ridge
deformation
the process by which the shape of a rock changes be cause of stress
density
the ratio of the mass of a substance to the volume of the substance; commonly expressed as grams per cubic centimeter for solids and liquids and as grams per liter for gases
viscosity
the resistance of a gas or liquid to flow
subsidence
the sinking of regions of the ground surface with little or no horizontal movement
inner core
the solid layer of the core it is solid made of iron and nickel most dense and heaviest layer
mesosphere
the strong, lower part of the mantle
Pangaea
the super continent that formed 300 million years ago and that began to break up 250 million years ago
plate tectonics
the theory that explains how large pieces of the lithosphere, called plates, move and change shape
seismic waves
vibrations from an earthquake
Ring of fire
volcanic mountains
crust, mantle, and core
what are the chemical layers of the earth
lithosphere, asthenosphere, mesosphere, outer core, and inner core
what are the physical layers of the earth
the crust, mantle, and core
what are the three layers of the earth, based on their chemical composition
continental or oceanic
what are the two kinds of crust that a tectonic plate may contain
collide, separate, and slide
what are three ways that tectonic plates can move relative to each other
large mountains
what can form when compression squeezes rocks at a convergent boundary
the global positioning system
what do scientists use to measure the rate of tectonic plate movement
iron
what element makes up most of the earth's core
same plant and animal species rocks and mountain ranges climatic conditions
what kinds of evidence supported Wegener's theory
oxygen, silicon, and aluminum
what three elements make up most of the crust
volcanic mountains
what type of mountain range is formed when magma rises to the earth's surface and erupts
folded mountains
what type of mountain range is formed when rock layers are squeezed and forced upward?
fault-block mountains
what type of mountain range is formed when tension causes large blocks of crust to drop down
reverse fault
when compression pushes rock together, it creates a ________________________________
convection current
when hot rock from deep within the earth rises but cooler rock near the surface sinks
strike-slip fault
when opposing forces cause rock to break and move horizontally, they create a ____________________________________
sink below the surface
when rock cools, it becomes more dense and tends to _________________________________________.
rise
when rock is heated, it becomes less dense and tends to __________________.
fault
when rock layers break, the resulting surface they break and slide on is called a ___________________
mountain ranges
when tectonic plates collide, folds and faults can become_______________________________
normal fault
when tension pulls rock apart, it creates a ___________________________________
rebound
when the earth slowly springs back into elevation
the continental crust is pushed upward and crumples and folds
when two plates with continental crust collide, what happens to the continental crust
all of them transform creates the most
which type of boundary produces earthquakes
transform boundaries
which type of boundary produces strike-slip faults
each tectonic plate fits next to the plate that surrounds it
why are tectonic plates like the pieces of a jigsaw puzzle
heavier elements are pulled towards the center of the earth by gravity
why do less dense compounds make up earth's crust while the densest compounds make up the core
magma from underwater volcanoes give clues about the ocean floor
why do scientists look at the ocean floor to research the mantle
it contains more iron, calcium, and magnesium
why is oceanic crust denser than continental crust
a seismic wave will travel more quickly through a solid because a solid is denser than a liquid
will a seismic wave travel more quickly through a solid or a liquid and why
Mid ocean ridges
Areas where sea floor spreading occurs
New oceanic lithosphere forms
In the process of sea floor spreading, what happens when magma rises to earths surface and solidifies
Magnetic reversals
The process that happens when earths magnetic poles change place
Pangaea Gondwana Lauraisa continents
Wegener thought that all of the present continents were once joined 245 million years ago in a landmass he called ___________________. The single landmass split into two huge continents he called _______________ and _________________. when those two continents split 65 million years ago, the ________________ we know today formed.
Geologist Alfred Wegener noticed similar rocks & fossil remains were found on continents which seemed to fit together
What did Wegener notice
From the calculated strength of the rocks, it didn't seem possible foe the crust to move in this way
Why did many scientists reject Wegener's hypothesis
fault
a break in a body of rock along which one block slides relative to another; a form of brittle strain
syncline
a downward, troughlike fold in a rock layer
monocline
a fold where both ends of the rock layer are horizontal
asthenosphere
a layer of slowly flowing rock in the mantle it is not a liquid or a solid but like a thick paste
compound
a substance composes of two or more elements