Ocean Circulation

Question 1

reasons we study the ocean

Answer 1

food, transportation, recreation, influences atomsphereic weather and climate

Question 2

earth’s five ocean basins

Answer 2

pacific, atlantic, indian, arctic, southern

Question 3

mid-ocean ridges

Answer 3

longest mountain range in the world

Question 4

active continental margins

Answer 4

tectonically active zones, subduction zone, small width and sediment input (left side of south america)

Question 5

passive continental margins

Answer 5

are within plates and low tectonic activity, generally wide, receive large influx of sediment input (right side of south america); not a plate boundary

Question 6

list the three major layers in the oceans regarding density

Answer 6

surface layer,transition/thermocline, deepzone

Question 7

surface layer

Answer 7

warmest, 100 m deep. makes up only 2%

Question 8

transition/thermocline layer

Answer 8

makes up 18%, 1500 m, just above freezing point

Question 9

deep zone

Answer 9

makes up 80%, temperature is low and constant

Question 10

seawater

Answer 10

salinity is around 3.5%, salt can be removed by biological organisms, common evaporation and freezing, salinity in oceans is essentially constant

Question 11

salitinity increases when…

Answer 11

evaporation, chemical weathing from land release elements, volcanic eruption, freezing of sea water

Question 12

salinity decreases when

Answer 12

fresh water from land/preciptation, plant and animals take elements

Question 13

ocean surface motion

Answer 13

caused by winds that drag the surface of the water, sun energy, controlled by wind

Question 14

ocean depth motion

Answer 14

the deep water flow and surface current is quite different, driven by temperature and salinity, controlled by density

Question 15

when there is high salinity

Answer 15

there is high density and water tends to sink

Question 16

when there is low salinity

Answer 16

there is low density and water tends to float

Question 17

thermohaline circulation

Answer 17

“the great ocean conveyor belt,” driven by differences in temperature, salinity, and density

Question 18

importance of thermohaline circulation

Answer 18

distributes solar energy, maintains earth’s climate by transporting heat from the equator to the poles, nutrient distribution, oxygen distribution

Question 19

since the majority of the world population live within 100 km of the coast line…

Answer 19

we depend of the ocean as a resource and means of transportation, for human activities, and humans are vulnerable for hazards from the ocean

Question 20

long-term sea level change

Answer 20

global climate change, expansion and contraction of ice caps, imperceptible with human life time but significant over a geologic time

Question 21

short-term sea level change

Answer 21

tides, perceptible by human, caused by gravitational attraction of moon and sun, the attraction of the sun is weaker than the moon