discussion questions Flashcards
why study the formation and structure of the ocean floor
to understand organisms
what is the continental drift hypothoesis
tectonic plates move apart as new crust is formed at the boundary
what is uniformitarianism
the forces are still working and the earth is still changing
what is bathymetry
mapping ocean floor
what is echo sounding used for
bounces sound off the floor and times to see how long it takes to come back to work out distance to the floor
what is the principle of satellite altimetry
gravity pulls water towards objects
what is a gravimeter
spring that extends over denser materials
what does seismology tell us about the earths interior
heterogeneous layers
compare and contrast P and S waves
P type goes through solid and liquid but S can only travel through solid
what are some other sources to determine Earth’s structure and composition
rock sampling, lava, magma and comets and asteriods
what are the major layers of the Earth
crust, lithosphere, asthenosphere, mesosphere, core
what is the densest layer of the earth
inner core
which layer is liquid
outer core
besides liquid outer core what materials are the other layers
lithosphere and mesosphere and inner core are rigid. asthenosphere is plastic
what is isostatic equilibrium
a cool ridged lithosphere is supported by hot asthenosphere. solid material on top displaces melted material below
what is older, oceanic or continental crust
continental
where can you find earths oldest rocks
on the continent 280 million years
what is pangea
supercontinent
what are mid ocean ridge basalts and where are they formed
formed at diverging ocean plates, mid-atlantic and east pacific rise
what is granite and how does it differ from basalt
on continent and low iron
what are magnetic stripes and how are they formed
formed by reversal of magnetic field, particles cool and solidify with certain direction
what is the seafloor spreading hypothesis
new oceanic crust formed as plates pulled apart
what are the major sources of the earths heat
radioactive decay
how does heat move from the interior to the surface of the earth
conduction and convection
Hawaii islands are generally classified as what type of volcanism
hot spot mantle plume at a fixed point as crust is moving
where is earths fresh water mainly sorted
glaciers
would global warming reduce or increase fresh water
reduce
which is larger, average depth of the ocean or average land elevation
ocean
where is earths tallest mountain
hawaii
where is earths tallest elevation
everest
where is earths deepest part
mariana trench
where are earths seismic activities located
seismic plate boundary
what is the pacific ring of fire
converging plate boundaries
what are the 3 major types of plate boundaries
diverging, converging and transform
what is the difference between abyssal hills, guyots and atolls
abyssal hills are faulted plate movement
guyots - volcanoes that didn’t break the surface, extinct and flat
atolls - formed when volcanic islands subsides from barrier reef
what does a hypsometric curve tell us about the surface area of the earth
deepest trench is taller than shortest mountain
what are the two main subdivisions of the seafloor
continental margin and deep ocean basin
what are the two types of continental margins
active- converging plate boundaries and passive
what are the 4 components of the continental margins
continental shelf, continental slope, continental rise and shelf break
what kind of plate boundary do oceans form
diverging
how can you tell the difference between a slow-spreading and fast-spreading center?
fast spreading has little variation in height - pacific
slow spreading has abysall hills - atlantic
describe igneous
formed by cooling magma or lava
describe sedimentary
layers of sediment under pressure form sedimentary rocks
describe metamorphic
other rock types change into this due to heat, pressure and other physical and chemical conditions
why do dominant rock types differ between the most abundant within the crust and on the earth’s surface
ingenous on crust and sedimentary on the surface. weathering and biological process on the surface
what are the two main types of sediment
clastic - pre existing rocks physically transported
non-clastic - chemical or biological precipitation
differentiate between neritic and pelagic sediments
neritic is mainly terrigenous sediments
pelagic is biogeneous
what are the common organisms that cause oozes
diatoms - siliceous
forminifera - calcium carbonate
