Type of mountain, extinct volcanoes, rise more than 1000m, but do reach surface, flat topped seamounts are called guyots – tops removed through wave action

steep-sided, long, narrow depressions or basins, - deepest regions on earth, these Are found close to land, nestled against continental margins, assoc. w/ earthquakes

in marianas trench, deepest point in the earth's oceans

10,924 meters below sea level

1885

giant puzzle- how does it fit together

fern in india, australia, s. africa, s. america

contraction hypothesis

1912

"could these land masses have been joined together at one point and subsequently drifted apart"

Pangaea 200 million years ago

1. fit: 2 seas: pathalassa and tethys sea

2. mountains- appalachian extend to greenland, united kingdom, and norway

3. glaciers- s. america, s.africa, tip of india, australia, and antarctica (huge glacier stuck together at s. pole or one world wide iceage)

4. fossils- fern in australia and antarctica, and reptiles in africa and s. america

.4% 

35-40 km

low density rocks made of aluminum, silicon, and oxygen 

68.1%,

~2900km,

dense, hot rocks of magnesium, iron, silicon, and oxygen  

o   31.5%

~3500km

outer core- liquid

inner core-solid made of iron and nickel

1950s

found underwater trenches

WW2 kept his depth recorder on all the time

noticed: 

extensive mountain ridges in the center of ocean basins

deep ocean trenches at the end of ocean basins

very thin sediment in deep ocean

o   New ocean crust formed at ridges

o   Volcanoes that form along the ridge are originally close to the surface of the ocean where they can be eroded flat on top

o   Deep ocean trenches are where the seafloor finally descends back into the mantle

o   Mud and sediments deposited on the ocean floor are thin toward the mid-ocean ridges is because the age of the seafloor gets younger, thus less and less time to accumulate sediments

o   P.s He failed his first course in mineralogy at Yale and was told he had no future in the field…Harry Hess

first measured the magnetic field in 1835

·      Flips- every 200,000 years on average- of course this is variable! However, the time between reversals is highly variable

·      The last time Earth’s magnetic field flipped was 780,000 years ago, according to the geologic record of Earth’s polarity

·      Time for a flip? Needs to be far below 8 for a flip

heat passing through a substance

(spoon in hot water)

flow of heated material itself

(air, water, molten rock)

1. continents plow through ocean basins

calculations showed this to be incorrect

2. continents moved because of gravitational attraction of equator and sun/moon

forces are too small