Lec 2

Question 1

The solid Earth is composed of plates floating

Answer 1

on liquid mantle

Question 2

Oceans are formed when

Answer 2

2 plates separate from eachother

Question 3

In the middle, ascending mantle material makes a

Answer 3

mid ocean ridge

Question 4

subduction zones

Answer 4

In areas where two continents are pushing against each other, one sinks underneath the other producing these that create deep trenches

Question 5

what displaces more volume? solid or liquid water

Answer 5

solid water (ice) displaces more volume (therefore it floats)

Question 6

Water can dissolve more things than any other natural substance, including

Answer 6

salt, gases, and organic molecules

Question 7

Seawater contains

Answer 7

many solutes, mostly salts in the form of ions (1 kg of seawater has approximately 35 grams of dissolved salts)

Question 8

whats heavier? seawater or pure water

Answer 8

sea water

Question 9

seawater also contains

Answer 9

dissolved gases that are exchanged with the atmosphere: gas exchange (vital for living organisms)

Question 10

the ocean is usually

Answer 10

stratified/layered

Question 11

The number of ocean layers vary with

Answer 11

environmental conditions and is determined on the physical properties of water masses (density - temperature and salinity)

Question 12

ocean layers are separated by

Answer 12

thermoclines (transitional areas in which there is a sudden change in temp) and haloclines (…sudden change in salinity)

Question 13

3 ocean layers

Answer 13

• surface layer (mixed) down to 100-200m (mixed by wind and currents)
• Intermediate layer: down to 1,000-1,500 m (separated by the main thermocline)
• Deep layer: below 1,500 m (very stable conditions)

Question 14

Ocean circulation and movement is caused by:

Answer 14

The Coriolis effect and wind patterns
Thermohaline circulation
Tide forces
Wave action

Question 15

Coriolis effect is caused by

Answer 15

curvature and rotation of the Earth

Question 16

The Coriolis effect creates

Answer 16

circular movement of water and air particles
(Currents rotate in opposite directions in the northern and southern hemispheres)

Question 17

wind is caused by

Answer 17

heat energy

Question 18

ekman transport/spiral

Answer 18

The movement from the surface layer of water is transmitted to the water below, but also at a 45 degree angle caused by the Coriolis effect

Question 19

most visible result of Coriolis effect

Answer 19

ocean surface circulation

Question 20

thermohaline circulation

& produces

Answer 20

Because denser water sinks (colder and saltier), it leaves a void that it is filled in by less dense water
& produces great ocean conveyer

Question 21

The tidal force

Answer 21

produced by the Moon and the Sun on the Earth’s ocean is the vector difference between the gravitational force exerted by the Moon or the Sun on water particles, and the gravitational force that would be exerted on water particles if they were located at the center of mass of the Earth

Question 22

spring tide

Answer 22

During new and full moon the Sun, Moon and Earth line up – tidal forces due to the Sun reinforce those of the Moon

Question 23

neap tide

Answer 23

When the Moon is at first or third quarter, the Sun and Moon are separated by 90° – the forces due to the Sun partially cancel those of the Moon

Question 24

types of tides

Answer 24

• Semidiurnal: two high tides and two low tides each day
• Diurnal: one tidal cycle per day
• Mixed. (most places) Because of the diurnal contribution, there is a difference in height (the daily inequality) between the two high tides on a given day

Question 25

Waves are caused by

Answer 25

winds but in some rare cases by earthquakes and landslides

Question 26

The size of wind waves depends on the

Answer 26

fetch, the span of open water over which the wind blows