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Flashcards in Oceanography Deck (47)
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1
Q

what is thermocline?

A

the thermocline is the transition layer between surface layer and bottom layer. (temperature)

2
Q

what is the halocline?

A

the halocline is the transition layer between fresh water and salt water

3
Q

what is the measurement for salinity?

A

ppt–parts per thousand

4
Q

what is salinity? how much salt is in the ocean?

A

salinity is the measure of salt dissolved in water.

3.5% or 35ppt = salinity in ocean

5
Q

what is upwelling? what does it bring up?

A

wind blows water and then cold water rises. that water brings up fish and food.

6
Q

what is downwelling? what does it bring down?

A

water goes downward. brings down oxygen, food, heat

7
Q

why does ice float?

A

ice freezes and then expands. the way ice freezes is water molecules create a 102 degree angle which creates the crystal shape. then the crystal shape causes it to expand. it is less dense than water.

8
Q

what temperature is water most dense at?

A

4 degrees Celsius

9
Q

how can you increase density of sea water?

A

by taking away fresh water.

evaporation and freezing

10
Q

how can you decrease the density of sea water?

A

by adding more fresh water.

water melts from LAND, rain/snow, rivers

11
Q

what is oceanography?

A

study/ mapping of the ocean floor

12
Q

how is the water distributed in the world?

A

97%=saltwater: oceans

3%=freshwater: ice caps, rivers, lakes, underground

13
Q

what are 3 ways sea levels change?

A

temperature, plate tectonics, melting ice

14
Q

how does temperature affect sea levels?

A

when temp rises, water expands, sea level rises.

when temp falls, water condenses, seal level falls.

15
Q

how does plate tectonics affect sea levels?

A

rising and falling of the sea floor

16
Q

how does melting ice affect sea levels?

A

when ice from land masses melt, goes into ocean, level rises.
when ice forms on land, takes away from ocean, level drops

17
Q

how much of the world is covered by oceans?

A

71%

18
Q

list the 5 oceans by size

A

Pacific, Atlantic, Indian, Antarctic, Arctic

19
Q

which ocean is shrinking? why?

A

Pacific; because of subduction zones, the continents are getting pushed together

20
Q

which ocean is growing? why?

A

Atlantic; because of mid oceanic ridge, new sea floor

21
Q

what is the new ocean?

A

Ethiopian ocean, 10 million years is expected

22
Q

what are the 3 characteristics a body of water needs to be classified as a sea?

A

partially/mostly land locked
saltwater
part of water (ocean) circulation

23
Q

how is water a good buffer?

A

water stores heat. it absorbs heat during day and releases it at night. this allows for less drastic temp swings

24
Q

what is a salt? what is most common salt in ocean?

A

a metal + a non metal

NaCl is most common in ocean

25
Q

what is the density of sea water?

A

1.02 - 1.03 g/cm3

26
Q

how is the density of oceans affected?

A

by temperature and salinity

27
Q

how far can light travel in the ocean? and what light goes farthest?

A

100 meters.

red is absorbed first, blue goes farthest

28
Q

no surface layer = ?

A

no thermocline

29
Q

Gyers do not cross the ___

A

equator

30
Q

gyers in the northern hemisphere move ____

gyers in the southern hemishpers move ____

A
northern= clockwise/right
southern= counterclockwise/left
31
Q

what do gyers move around?

A

heat

32
Q

what is the longest mountain ridge on Earth?

A

the mid Atlantic ridge

33
Q

where does the hydrothermal vent get its heat?

A

earth’s mantle/magma

34
Q

when did oceanography begin and what was the first vessel to explore the ocean floor?

A

began in late 1800s

The Challenger

35
Q

ocean temps can very from ___

A

-2 to 35 degrees Celsius

36
Q

land temps can vary from ___

A

-70 to 35 degrees Celsius

37
Q

Water becomes denser until ___ and then ___

A

4 degrees C ; expands

38
Q

In the Pacific, the ridge is ___ faster than new floor created which means the ocean is getting ___

A

subducting, smaller

39
Q

what is the salinity in the subtropical and why?

A

37ppt; increased evaporation increases salt ions

40
Q

what is the salinity in the tropics and why?

A

32-33ppt; lots of rain= more fresh water

41
Q

salt water freezes at ___

A

-2 degrees Celsius because takes more energy to freeze salt ions

42
Q

ancient seas and todays seas have same salt levels. how do we know?

A

evidence found in old and new sea shells and fossils

43
Q

what creates the densest sea water?

A

high salinity + cold temp = densest water

44
Q

water ___, leaves behind ___, cold water sinks beneath ice and becomes ___ and ___, then ___ and migrates to the ___

A

freezes, salt, saltier, denser, sinks, equator

45
Q

why do gyers not cross the equator?

A

because southern and northern hemisphere currents are opposite

46
Q

where the sea floor drops off quickly?

A

slope

47
Q

what is the flattest part of earth?

A

abyssal plains