Ocean Water and Sea Basins Flashcards
Oceans cover __ percent of the Earth’s surface
70
The ____ of ocean water is still under scientific debate
origin
The land on the globe is concentrated in the ______ hemisphere
northern
The Southern Hemisphere is primarily…
oceans with very little land
which hemisphere contains all of our major continents?
northern
Does the uneven distribution of land affect large scale ocean water circulation?
Yes
the uneven _____ of land affects large scale ocean water ______
distribution, circulation
What are the four main, main,interconnected ocean basins comprising the world ocean?
Pacific, Indian, Atlantic, and Southern
when all of the continents were joined in the supercontinent Pangea, ocean currents were..
very simple
As the continents split apart, ocean currents became more…
complex
Where is the deepest part of the ocean? How deep is it?
- Marianas Trench
- 11km at its deepest. 4.5 km average
The overall topography of the ocean floor: there is a continental _____ that is part of the crust that _____ downward to the ocean _____.
shelves, slopes, floor
What is the ocean floor also called?
the abyssal plain
Oceanic crust, on average, is ______ then continental crust
younger
How old is the oldest oceanic crust?
200 million years
Oceanic crust is younger because it is rapidly _____ through ______ at subduction zones and ______ at mid ocean ridges
renewed, destruction, formation
margins between continents can be either _____ or _____
active, passive
margins between continents can be either active or passive depending on…
tectonic activity at the margin
margins between continents can be either active or passive depending on ______ activity at the margin.
tectonic
Is there a lot of sediment deposited in the deep ocean floor?
No
why is there scarce sediment deposited in the deep ocean floor?
because it is too far away form any source of sediment (land)
what is one way that sediment reaches the ocean floor?
turbidity currents
turbidity currents are like ______ under the water
landslides
Turbidity currents can be considered as avalanches that flow down the ______ slope
continental
where do turbidity currents flow from?
the continental slope
why is the sediment layers in turbidity currents?
As the sediment flows it divides itself up into different sized particles
where do turbidity currents deposit their load?
At the base of the slopes
Is the sediment in turbidity currents more for less dense than the ocean water?
more
what is sediment-rich water that is denser then the rest of the ocean water and flows along the ocean floor to deposit?
turbidity currents
the salt content of seawater is ___ percent
- 5
- this means that if you had 100 gallons of seawater and you evaporated all of the water you would be left with about 3.5 gallons of salt
The salt material in oceans comes from the ______ or rock and ______ to sea by rivers
weathering, transport
Can volcanic activity add salt to seawater?
yes
evaporation and freezing tend to _____ in sea water
concentrate
why does evaporation and freezing tend to concentrate in sea water?
because when water evaporates or freezes it tends to leave the salt behind
when water evaporates in an ocean basin, only the ____ evaporates and the _____ is left behind
water, salt
How can slat be removed from the ocean?
by biological organisms who use it in their metabolism or to make their shells.
Seawater is diluted by…
freshwater influx from precipitation and rivers
freshwater can travel far into the ocean before it completely ______ with the ocean water
disseminates
