Unit 4: Test
germane scientist ______ _______ came across a paper listing identical _______ _______________ he began to question
Alfred weaner fossils on either side of the Atlantic Ocean
rock isn the asthenosphere is ________. The rock of the asthenosphere is _____ like _______.
abl to flow soft, putty
Lava comes from deep beneath the ground and gives us ____ about the _____ inside the Earth
clues conditions
result from ________ _____
compression force
_______ _______ is less dense and contains mostly silica-rick minerals, whereas _________ is denser and contains more iron-bearing minerals. ________ is also thicker than oceanic crust
continental crust oceanic crust continental crust
the continents appear to fit together like puzzle pieces. this clue was the starting point of the development of a hypothesis about Earth's moving crust called the
continental drift hypothesis
the crust is made up of the _______, __________, ________, _________
continents, continental crust, ocean floor, oceanic crust
Flow of the rock is in the asthenosphere is due to _____.
convection
a ______ boundary formed when two plates move together
convergent
earthquakes also happen at divergent boundaries as plates move apart releasing pressure. These earthquake tend to be smaller than those that happen at ____ or _______ boundaries
convergent or transform
the centermost part of the Earth's interior is called the
core
at a transform boundary, ______ us better made or ______, instead the gates grind past one another horizontally
crust destroyed
as the ____ plate beings to subduct bent the _____ ______ plate, gravity starts to pull the subduction plate into the ______
denser less dense mantle
tectonic plate motion causes pressure to build. the sudden relate of this pressure causes an _____. This can happen in several ways
earthquake
magic eruptions are usually nonexplosive. felsic magma usually results in _______ ______
explosive eruptions
the pressure caused by tectonic plate movement can break the crust further into the plate forming a ____. the formation of a fault releases the pressure as does movement of rocks along a preexting fault. both events can cause an ______
fault earthquake
_____ magma is rich in silica and aluminum. it has a high viscotiy
felsic
Wegener noticed that deposits of _____ ______ have been found on opposite sides of an ocean
glacial sediment
as new crust is forming at the spreading center. it pushes the older crust part. because of this, the oceanic crust contains symmetrical patterns of crustal crock ages. these rocks _______ in age as their ______ from the _______-______ ____ increase
increase distance mid-ocean ridges
the centermost part of the core, the ________ is solid. The pressure on the inner core is so great, it does not _______.
inner core melt
scientists know that s waves cannot travel through _______.
liquid
therefore, they could infer the presence of an outer, ______________ called the core
liquid portion of the core
_____ magma is rich in iron and magnesium. it has low viscosity
mafic
the tectonic plates that make up earth's lithosphere "float" above the mantle? what is that called
mantle convection
beneath the asthenosphere, the pressure is too great for rock to flow. This deeper lawyer of the mantle where rock cannot flow is called the
mesosphere
the core is mostly _______, _______, ______ though it possibly contains small amounts of sulfur
metal, iron, nickel
at seafloor spreading centers, the _____-______ ______ constitutes an area of high elevation on the sea floor
mid-ocean ridge
new oceanic crust is formed at _____-______ _____ = oceanic rift zones where crust is pilled apart (_____) plates move apart and ________ ________ _________ occurs
mid-ocean ridges divergent sea floor spreading
the convergence of 2 continentals plates produces a _______
mountains
mantle convection drives the formation of oceanic crust, the ______ ______ _______ ________.
movement of the plates
transform boundaries can occur under the _____ or _______
ocean or land
________ ________ forms continually as lava rises from the mantle at mid-ocean ridges and cools into hard rock. _______ ______ is also continually recycled as it sinks back into the mantle in deep ocean trenches through the process of subduction
oceanic crust oceanic crust
new _____ _____ is continually being formed at seafloor spreading center. older crust is continually being destroyed at ______ _____
oceanic crust subduction zone
divergent boundary can occur between two _____ plates or two ______ plates
oceanic or contiental plates
divergence does not occur between an ______ plate and a _________ plate
oceanic or continental
this type of boundary can form between two _____ plate, two __________ plates, or an ______ and a _________ plate (convergent)
oceanic, continental
It makes up approximately ______ of Earth's mass
one-third
____ ____ are compressional body waves. They cause rock to expand and contract as they pass through. P Waves are the _____-___ seismic waves
p waves fastest moving
Wegener proposed that about 300 million years ago al the continental were joined together to forma a supercontinent which he named _____. The continents drifted slowly over time to their current positions
pangaea
volcanoes form along ______ boundaries at _____ _____
plate hot spots
this further drives tectonic plate movement in a process called
ridge push
a ____ _____ is a valley that forms between tectonic plates that are moving apart
rift valley
as scientists studied recording of earth waves, or seismograms, they noticed a shadow zone through which some waves called _______ do not pass
s waves
__ _____ are transverse or shear waves. They cause rock to move up-and-down or side-to-side, perpendicular to the directions hat the waves are traveling. S waves cannot travel through ______ or _____. They are the _____ ______ seismic waves
s waves liquids or gases second fastest
______ _______ is the process by which new oceanic lithosphere forms at mid-ocean ridges. as tectonic plates move away from each other, madam rises from Earth's interior. it then cools and solidifies in the center of the ridge. the rising madam pushes up between the plates and drives them _____ apart
sea floor spreading further
earthquakes produce body _____ waves that move through Earth's interior and surface seismic wave that move only along the ground.
seismic waves
what are three types of volcanoes
shield, composite, cinder cone
this further drives tectonic plate movement in a process called _______ _____
slap pull
oceanic plates can slide down this higher elevation toward a ______ _____
subduction zone
when an oceanic plate converges with a continental plate, the denser oceanic crust sinks below the continental crust along a unique region called a _______ _____
subduction zone
can form a _____ _____ (oceanic-continental) or a ______ _____ (continental-contiental)
subduction zone convergence zone
tectonic plates are destroyed at _____ ______. __________ ______ beneath a less dense plate. The diner plate then melts in Earth's _____.
subduction zones (2) mantle
______ _____ are the _____ seismic waves. the ground shaking they produce cause most of ______ from earthquakes
surface waves slowest damage
the brittle nature of the lithosphere causes it to crack under stress. The lithosphere is broken into large pieces called
tectonic plates
result from _____ or ______ forces
tension or extensional
lava comes from the top art of the mantle called
the asthenosphere
the outer, rocky layer of Earth that we love on and observe directly is called
the crust
together with the top part of the underlying layer, the mantle, these two types of crust make up the brittle part of the Earth which is called
the lithosphere
this layer is separated into tectonic plates. the tectonic plates are constantly moving together and apart. this phenonmeon is known as the
theory of plate tectonics
a ______ boundary forms when two plates slide past one another horizontally
transform
a ____ is a deep valley that outline a subduction zone
trench
thick layer makes up ________ of Earth's mass
two-thirds
a _______ ____ is a series of volcanoes that forms behind an ocean-ocean subduction zone
volcanic arc
a _____ is a geological feature that forms around fissure in Earth's crust
volcano
The deepest mines are about ______ _____ deep, the center of the Earth is about ________ _____
2 miles 4,000 miles