Earth science exam 2
Terms
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- Alfred Wegener
- A scienctist who was also trained in astronomy and geophysics and was a professor of geophysics and meteorology
- Pangaea
- name of the single landmass that broke apart 225 million years ago and gave rise to today's continents.
- Gondwanaland
- supercontinent in the Southern Hemisphere, which included South America, Africa, peninsular India, Australia, and Antarctica
- Lauraisa
- supercontinent that broke off from the Pangaean supercontinent in the late Mesozoic era. It included most of the landmasses which make up today's continents of the northern hemisphere
- Evidence for continental drift
-
match of continental drift
Continuity of Mountain Belts
Geological Formations
Fossils of the Upper Paleozoic fern,
Glascial Deposits & Paleoclimate(occur in southern hemisphere) - Why was he theory of the continental drift rejcted?
-
continent fit wasnt perfect, correlation of rock units was weak, tillites werent glacial deposits, northern hemisphere colas werent tropical.
wegener wasnt a geologist so his credicility was attacked
No mechanism - layers of the Earth
- Crust, Lithosphere, Mantle, Inner Core, Outer Core
- Crust
- outer skin and very thin. 25-70 miles thick
- Lithosphere
- uppermost part of the mantle. oceanic and continental crust
- Mantle
- thickest layer
- Inner Core
- behaves like a solid due to the increased pressure
- Outer Core
- liquid which generates the Earth's magnetic field
- Evidence for Plate Techtonics
- Paleomagnetism, seafloor spreading, patterns of earthquakes and valcanoes, hot spots
- lithosphereic plates
- Euraisian Plate, Pacific Plate, Antartic Plate, North American Plate, South American Plate, African Plate, Caribbean Plate, Indo-Australian Plate
- Plate Boundaries
- Divergent, convergent (oceanic oceanic, oceanic continental, continental continental) Transform
- Divergent
- moving apart-rifts- valcanoes (not explosive)
- Convergent
- coming together
- oceanic oceanic
- islands are valcanoes (explosive)
- Ocanic continental
- mountains/valcanoes (explosive)
- continental continental
- mountains, stacking (earthquakes)
- transform
- earthquakes
- subduction
- downwellign of the earth's lithosphere
- valcano
- a valcano is a weak spot in the crust where magma, comes to the surface
- where are valcanoes found
- aroudn the ring of fire
- why does magma rise?
- rises because liquid magma is less dense than the surrounding solid material, gasses dissolved in magma rush out
- what determines if a valcano will erupt?
- viscosity, gas content, and temperature, silica content
- parts of a valcano
- crater, lava, pipe, vent, magma chamber, magma, side vents,
- 3 stages of a valcano
- active, dormat, extint
- active
- one that is erupting or has shown signs that it may erupt in the near future
- dormat
- one which is expected to become active in the future
- extinct
- volcano has typically not erupted for thousands of years and is unlikely to erupt again
- sheild valcanoes
- layers of lava pour out of the vent and harden on top of previous layers, lave flows gradually build up a wide, gently sloping mountain
- cinder cone
- ash cinders and bombs build up and pile around the vent in a steep cone-shaped hill
- composite valcano
- tall cone shaped mountains in which layers of lava flows alternate with explosive eruptions of ash, cinder, and bombs
- what is an earthquake
- the vibration of earth produced by the rapid release of energy
- focus
- poitn beneath earths surface where rick breaks under stress and causes an earthquake
- epicenter
- the point on earths surface directly above and earthquakes focus
- what are earthquakes associated with?
- earthquakes are associated with faults
- p waves
- push and pull waves, they can travel through all mediums, they arrive first
- s waves
- right angle waves, they can only travel through solids, they arrive second
- surface waves
- up and down and side to side motion, produce most damnage and arrive last
- what is a tsunami
- waves produced by the tidal effect of the moon or the sun