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75 terms

science

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The continent they think the continets were once all a part of?
Pangea
Who had the continental drift idea in 1915?
Alfred Wegner
What evidence was found proving that the continetal drift happened?
fossils rocks and mountain ranges
Coastline evidence?
the shape of the coastlines were evidence
How was the ocean depth determined?
technology using sound waves
Best fossil evidence of animals?
land animals
How were the fossils found to be evidence?
It was believed the living things fossils were distributed
What could Wegner not explain?
He could not explain how they split apart
How did Wegner say htey split apart?
He said the seafloor seperated
Mid ocean ridge
system of mountain ranges on seafloor seperated by valleys
Who provided the idea of mid ocean ridge?
Hess
What did Hess think the magma did?
He thought the magma is buoyant and rises upward through the cracks in the crust
rift valley
long narrow depression
What was the evidence on the seafloor?
rocks and sediments
What happened when the rocks hardened?
magnetic property spread along the floor
What was the plate tectonics theroy?
Earths surface is made of slabs of rigid rock that move over Earths upper mantle
What makes up the bottom part of the plate?
Solid layer of mantle
What makes up the top mantle?
Oceanic crust
Convergent plat boundaries
collide
subduction
where the plates dive underneath eachother
divergent
moving apart
transform plate boundary
moving horizontallly
convection
collective movement of ensembles of molecules within fluids (i.e. liquids, gases) and rheids. It cannot take place in solids, since neither bulk current flows nor significant diffusion can take place in solids.

Convective heat transfer is one of the major modes of heat transfer and convection is also a major mode of mass transfer. Convective heat and mass transfer take place through both diffusion
ridge push
proposed mechanism for plate motion in plate tectonics. Because mid-ocean ridges lie at a higher elevation than the rest of the ocean floor,
slab pull
tectonic plate motion due to higher densities
most popular gas thats erupted
water vapor
runny lavas viscosity
low viscosity
cinder cone volcanoes
small, short eruptions
shield volcanoes
broad falt structures composed of layers of lava low viscosity flow
composite volcanoes
large, steep shield, layers of lava and ash
shield volcano
forms above hot spots
earths outer core
liquid
lithoshere
crust and uppermost mantle combined
athenosphere
tectonic plates move on top of the upper mantle
what happens when pressure increases to the rock?
melting point of rock increases
magma
liquid stored inside the earth
what happens when magma is forced upward?
causes a split in the rock
what happens when magma reaches the surface?
causes a volcano
convergent boundaries
plates combine
hot spots
areas of volcanic activity where magma moves towards earths surface
viscosity
measure of fluid resistance to flow
low viscosity
flow more slowly
chemical composition
affects viscosity
silica
common in magma SiO2
pyroclastic material
solid material that erupts from a volcano
small particles
volcanic ash
large particles
volcanic cinder
earthquake
sudden movement or vibration of the ground that occurs when rocks slip and slide
where earthquakes occur
in tectonic plate boundaries
what percent occur along plate boundaries?
95 percent
what occurs when energy is realesed?
earthquake
forces applied to rocks along plate boundaries cause
earthquakes
compression stress
object is squeezed or shortened
tension stress
stretched or lengthened
shear stress
different parts move in different directions
torsion stress
object is stressed
plastic deformation
material changes shape as a stress is applied
fault
crack in earths crust
elastic rebound
sudden release of strain energy as rock moves along a fault
focus
point of origin of a earthquake
epicenter
directly above the focus
p waves
fastest travel through solids and liquids
s waves
slower only through solids
surface waves
only travel on the surface from side to side
richter scale
measures energy realesed during an earthquake , measures amplitude
mercalli scale
ranks earthquakes on intensity and amount of damage
damage is the greatest when
it is near the epicenter
what materials are the strongest
the ones that bend
what do seismic waves do?
help scientists investigate the earth
when waves chaneg speed they aslo can
change direction
refraction
change that causes a wave to bend and change direction
discontinuity
boundary between two layers of material that have different density
what are discontinuity identified by
seismic waves
shadow zones
areas on earths surface where no seismic waves are recorded
when do shadow zones occur?
shadow zones occur when s waves cant travel through earths outer core