Exam 2 Flashcards
U.S.S Atlantis (1931)
First research ship built specifically for ocean studies.
Meteor Expedition (1925)
First use of an echo sounder
HMS Challenger (1951)
Discovered the deepest part of the oceans deepest trenches.
Glomar Challenger (1968)
First deep sea drilling vessel
NOAA
- largest federal agency concerned with marine environment
- 2014 budget: $5.4 billion
The Big Bang Theory
A tremendous burst or energy and matter about 13.7 billion years ago.
What two pieces of evidence support Big Bang?
- Nearly all galaxies are rushing away from each other.
- the farther away a galaxy is, the faster it is moving away. - There is uniform background radiation throughout the universe that appears to be the left over heat from the Big Bang.
**the universe began long before Earth existed. **
What is our galaxy called?
The Milky Way
How galaxies are in the universe?
100 billion
What is a galaxy?
Rotating clusters of stars, dust, gas, and debris held together by gravity.
What is our neighboring galaxy?
Andromeda
Solar systems form by what?
Accretion
Where did the ingredients for Sun and planets come from?
- chemical reactions (deaths) of ancient stars = supernova
- energy, atoms released into space to form solar nebulae
What is accretion?
The process of smaller particles in the spinning nebular cloud clumping together to form larger objects.
How did earth form?
It formed as part of the accretion process during the condensation of the solar nebula.
How did earth become density stratified?
- as heat built up, earth began to melt
- melting caused the heavy iron & nickel to sink to the center, forming the core.
- more heat was released
- lighter materials (silicon, magnesium, aluminum) moved toward the surface forming the early crust.
- ** 1st surface 4.6 bya
How was the early atmosphere created?
Out gassing!
- no oxygen then
- methane, ammonia, and high amounts of carbon dioxide
Where did our water come from?
- out gassing
- icy comets
- oceans in place 4 bya
How long is a year? What is a solar year?
- 365 days
- time it takes for earth to complete one orbit around the sun
Closest to sun in early January:
Perihelion
Furthest from sun in early July:
Apihelion
Why do we have seasons?
- the earths tilt. 23.5 degree tilt
How long does it take the moon to orbit earth?
28 days. (1 month) lunar month
Lunar day:
24 hrs, 50 minutes.
It’s longer because the moon orbits the earth in the same direction that the earth rotates on it’s own tilted axis.
What are the 4 principle oceans?
- Pacific
- Atlantic
- Indian
- Arctic
Plus…
- Southern or Antarctic Ocean
What is a sea?
A division of an ocean or a large body of salt water partially enclosed by land
What is a gulf?
An arm of a sea or ocean partly enclosed by land
- larger than a bay
What is a strait?
A narrow passageway connecting two large bodies of water
What is a bay?
An indentation of a shoreline larger than a cove but smaller than a gulf
What is a sound?
A large sea or ocean inlet larger than a bay, deeper than a bight, wider than a fjord.
What is a river?
A natural watercourse, usually FRESHWATER, flowing toward an ocean, lake, sea, or another river.
What is a peninsula?
A geographical formation consisting of an extension of land from a larger body, surrounded by water on three sides.
What is a cape?
A headland that dramatically affects ocean currents.
The seafood can be divided into three distinct provinces:
- Continental margins
- Deep ocean basins
- Mid-oceanic ridges
What are continental margins?
Shelf + break + slope + rise
- the submerged edges of the continents
- covered by sediments eroded from the land.
Continental shelves are?
The shallow submerged edge of the continent.
Shelf breaks:
The abrupt transition from continental shelf to continental slope
What are continental slopes?
The transition between the continental shelf and deep-ocean floor.
What are continental rises?
Thick accumulations of sediment found at the base of the continental slope.
Passive vs. Active continental margins:
Passive:
- little or no seismic, volcanic activity
- smooth transition from continental crust to oceanic crust
- generally wide
Active:
- volcanic activity
- little or no shelf
- steep slope
- trench, no rise
What are submarine canyons?
Common features of continental shelves and slopes.
- turbidity currents (underwater landslides or avalanches) flow down submarine canyons.
- debris settles out, forms submarine fan at the base of the canyon.
What is the deep ocean province?
It’s between the continental margins and the mid-ocean ridge
What are abyssal plains?
Broad, flat area of sediment-covered ocean floor.
What are abyssal hills?
Most are small, extinct volcanoes.
- less than 1000 meters in height.
What are seamounts?
Volcanoes that rise up from the sea floor but DO NOT STICK UP ABOVE SEA LEVEL
What are guyots?
Flat topped seamounts
- once above the surface
- eroded flat by wave action and then sank further down.
What are oceanic trenches and how are they formed?
- deepest parts of the sea floor
- formed by subduction (one plate divides beneath another)
What are volcanic island arcs?
- curve-shaped group of islands
- often associated with deep ocean trenches.
Midoceanic ridge province:
- continuous submarine mountain range.
- covers 1/3 of the ocean floor
- extends 60,000 km around the Earth
What is the lithosphere?
Zone where crust fused with upper mantle
- strong, rigid
- makes up tectonic plates
- thicker in continental regions
What is the asthenosphere?
Beneath the lithosphere.
- weaker, deformable
- partially melted, like hot asphalt
What is the mesosphere?
Beneath asthenosphere.
- boundary of mantle and core
What is the order from less deep to more deep of the mantle layers?
Lithosphere
Asthenosphere
Mesosphere
What is waxing?
New moon to full moon
What is waning?
Full moon to new moon
What is the order of bodies of water from big to small?
Ocean - sea - gulf - bay
What is the average depths of our oceans?
4,000 meters
13,000 feet
Passive (. ) margins.
Atlantic
Active( ) margins
Pacific
The layers of the earth (blank) in temperature, density, and pressure from inside to outside.
Decrease
What are the two types of crust?
Continental crust: granitic rock
Oceanic crust: basaltic rock
Which is more dense, oceanic or continental?
Oceanic crust. Basaltic rock.
Name all the layers of the earth from outside to inside.
- Crust: Continental Oceanic - Mantle: Lithosphere Asthenosphere Mesosphere - Outer core - Inner core
What are the earths layers based on?
Temperature and density
