10.1 - 10.3 Notes Flashcards
What causes liquids to rearrange in layers
density
a thin outer layer of Earth
crust
made of basaltic rock more dense
oceanic crust
made of granitic rock
continental crust
what does MOHO stand for
mohorovicic discontinuity
what does the moho do
separates the crust from the underlying mantle
do earthquake waves increase or decrease speed when they reach the MOHO
increase
a soft weak layer beneath the lithosphere
asthenosphere (plastic mantle)
what are rocks close to in the asthenosphere
their melting point
what moves the soft hot rock towards the surface and the cooler rock further into the earth in the plastic mantle
convection currents
where do plates move
in the direction of the convection currents
earths outermost layer
lithosphere
what does the lithosphere consist of
crust and rigid mantle
a solid rocky shell that extends to a depth of 2890 km
lower mantle -stiffer mantle
the mantle composition was determined from
rocky meteorites
the deepest layers of the earth
core
what is the core composed of
iron and nickel
is outer core solid or liquid
liquid
the outer core has none of which waves
s-waves
does p-wave velocity increase or decrease in the core
increases
the p waves are _____ by the liquid outer core
refracted
the s waves are _____ by the liquid outer core
absorbed
oceanic crust is more or less dense
more
oceanic crust has more or less basalt
more
oceanic crust is thicker or thinner
thinner
oceanic crust is younger or older
younger
continental crust is more or less dense
less
continental crust has more basalt or more granite
more granite
continental crust is thicker or thinner
thicker
continental crust is younger or older
older
what are evidence of continental drift
the continental puzzle, matching fossils, rock types and landforms, ancient climates
Starting 10.2
whose continental drift hypothesis stated the continents once joined together to form a super continent
alfred wegener
the continents look as if they were pieces from what
a giant jigsaw puzzle
several of the same fossil organisms found in different landscapes is evidence of what
continental drift
several mountains belts that end at one coastline reappear on what
landmasses across the ocean
glacial striations and till are found in several continents that are now
warm
why did most scientists reject Wegener’s hypothesis
he could not explain how the continents moved
theory that the Earth’s surface is composed of several large, rigid plates that move because of convection currents in the mantle
plate tectonics
10.3 notes
hypothesis that the continents were moving and used to be one large landmass called Pangea
continental drift
theory that the earth is broken up into several plates that move because of convection currents in the mantle
plate tectonics
evidence of previous magnetic orientation preserved in the rock record
paleomagnetism
strongest evidence of seafloor spreading
strips of alternating polarity
how do strips of alternating polarity lie on the ocean floor
in mirror images
when rocks show the same magnetism as the present magnetic field
normal polarity
when rocks show the opposite magnetism as the present magnetic field
reverse polarity
the youngest oceanic crust is at the ridge crest and the oldest oceanic crust is at the continental margins
ocean drilling
ocean drilling proves
seafloor spreading
scientists found a close link between earthquakes, what, and what
plate boundaries and volcanoes ex. ring of fire
concentration of heat in the mantle capable of producing magma which rises to earths surface
hot spot
what moves over a hot spot producing the Hawaiian islands
the pacific plate
what do hot spots support
the evidence that plates move over earths surface
