Ocean - Water cycle

Question 1

Ocean cover ___% of Earth’s surface

Answer 1

71

Question 2

Ocean max depth

Answer 2

11 km

Question 3

The average depth of the ocean

Answer 3

4.5 km

Question 4

The average volume of ocean

Answer 4

1.35 (10)^18 m3

Question 5

Primary constituents of ocean salinity:

Answer 5

chlorine, sodium, sulfate, magnesium, calcium, potassium, bicarbonate

Question 6

Sources of ions in the ocean

Answer 6

dissolved load delivered from land from rivers, and from submarine volcanic activity (at mid-ocean ridges)

Question 7

Sinks of ions at the ocean

Answer 7

precipitation of minerals, sequestration by living organisms to produce shells, sorption of clay minerals, and reaction of basaltic seafloor rocks

Question 8

precipitation removes the following ions from the oceans:

Answer 8

sodium, chlorine, sulfate

Question 9

sequestration removes the following ions from the oceans

Answer 9

calcium, bicarbonate

Question 10

Sorption of clay minerals removes the following ions:

Answer 10

potassium and sodium

Question 11

The residence time of ions

Answer 11

The average time an ion spends in seawater

Question 12

The residence time of ions depends on:

Answer 12

the flux of an ion into seawater and the rate at which the ion is removed from seawater

Question 13

Distribution of salinity is high where:

Answer 13

high in regions of high evaporation and low precipitation

Question 14

salinity is low where:

Answer 14

river water enters the oceans

Question 15

Ocean currents play a major role in:

Answer 15

Ocean salinity

Question 16

Ancient ocean composition

Answer 16

Iron concentrations (Fe2+) were higher in proterozoic seawater, and thick banded iron formations were deposited as atmospheric oxygen increased and iron oxidized

Question 17

Areas on earth with the highest ocean temperature

Answer 17

Temperature is highest in the tropical pacific ocean and Indian oceans and decreases poleward

Question 18

The distribution of ocean temperature depends on

Answer 18

ocean circulation and amount of sunlight it is exposed to

Question 19

Temperature variation with oceanddepth

Answer 19

temperature decreases with depth

Question 20

Why temperature decreases with depth

Answer 20

cold water is denser and therefore sinks

Question 21

Thermocline

Answer 21

the upper zone of rapid temperature change in the oceans

Question 22

Salinity increases with:

Answer 22

depth

Question 23

Why salinity increases with depth

Answer 23

saline water is denser and sinks

Question 24

Holocene

Answer 24

a region of rapidly shifting salinity change in the coean

Question 25

Seawater density _____ as depth increases

Answer 25

increases

Question 26

Why seawater density increases with depth

Answer 26

due to decreasing temperatures, increasing salinity, and compression of liquid water with depth

Question 27

Pynocline

Answer 27

zone of rapid density change in the ocean

Question 28

Ocean currents are caused by

Answer 28

air currents (wind) interacting with the surface of oceans, sinking of denser (colder or more saline) water, and due to the rotation of the earth

Question 29

Deep currents are driven by

Answer 29

dense, cold, high salinity water descending at the poles

Question 30

Thermohaline circulation

Answer 30

the result of the density-driven movement of water in the oceans

Question 31

Thermocline circulation plays a critical role in controlling ______.

Answer 31

global climate

Question 32

How does the sun drive ocean currents

Answer 32

the sun heats the planet unevenly, resulting in energy differences that lead to wind directions. Frication acting between wind and water drives water movenet.

Question 33

Surface circulation is dominated by gyres driven by the ________.

Answer 33

Coriolis effect

Question 34

Coriolis effect

Answer 34

The surface of the solid earth is rotating about its vertical axis everywhere but the equator. Objects moving in a straight line then appear to curve relative to the solid earth beneath them.

Question 35

The earth is rotating ____ in the northern hemisphere

Answer 35

counterclockwise

Question 36

The earth is rotating ____ in the southern hemisphere

Answer 36

clockwise

Question 37

Objects moving in a straight line on the northern hemisphere appear to curve _____ relative to the earth beneath them

Answer 37

clockwise (right)

Question 38

Objects moving in a straight line on the southern hemisphere appear to curve _____ relative to the earth beneath them

Answer 38

counterclockwise (left)

Question 39

Ekman transport

Answer 39

The Coriolis effect causes wind-driven currents in the northern hemisphere to be clockwise of the actual wind direction. Deeper currents are progressively rotated CW because of slower water velocity. The net water movement is 90 degrees in the direction of the wind.

Question 40

Overall average water movement is _____ to wind in the northern hemisphere

Answer 40

90 degrees clockwise

Question 41

Overall average water movement is _____ to wind in the souhern hemisphere

Answer 41

90 degrees anti-clockwise

Question 42

Upwelling

Answer 42

Movement of deep, nutrient-rich ocean water to the surface where transport direction is offshore.

Question 43

Downwelling

Answer 43

occur where transport direction is onshore.

Question 44

Biotic life has ___ productivity in areas of upwelling

Answer 44

high

Question 45

Biotic life has ___ productivity in areas of downwelling

Answer 45

low

Question 46

El Nino

Answer 46

Normally, the coast of south america is one where Ekman transport drives the upwelling of nutrients to the surface. During an El Nino, upwelling will decline and trade winds reverse in the west pacific having an effect on weather patterns.

Question 47

In a normal year, surface currents off the coast of South America move ___, and Ekman transport causes ____ and movement of water ____.

Answer 47

northward
upwelling
offshore

Question 48

In a normal year, trade winds ___ which halts ___.

Answer 48

stop/reverse

upwelling

Question 49

Why El Nino is bad for fisheries

Answer 49

Water at the top few hundred meters warm-up lowering oxygen and nutrient concentrations due to slowed upwelling. Fish then have to go to greater depths to survive.
Red algae at the surface also cause mass death of fish.

Question 50

El nino frequency

Answer 50

4 years