Water Properties

Question 1

is water polar or non-polar?

Answer 1

polar

Question 2

why is water polar?

Answer 2

asymmetry of hydrogen atoms

Question 3

what are the benefits to water being polar?

Answer 3

• good solvent
• high heat capacity -> 1 calories to raise 1g of water by 1C
• high heat of fusion
• high heat of vaporization

Question 4

are all the elements in seawater not constant?

Answer 4

no they are all in constant proportions in all oceans

Question 5

what elements are used to measure salinity by chlorinity?

Answer 5

chlorine
sodium

Question 6

what is used to measure salinity by conductivity?

Answer 6

elements make saltwater conductive

Question 7

what is salinity?

Answer 7

of grams of elements in 1000g of water

Question 8

what makes salinity vary?

Answer 8

varies by latitude due to evaporation and precipitation
- more locally by sea ice formation and river input

Question 9

what are thermoclines?

Answer 9

vertical temperature
- gradient in temp

Question 10

what are haloclines?

Answer 10

salinity gradients

Question 11

what kind of water is dense and sinks?

Answer 11

cold saline water

Question 12

how much of Earth is covered by water?

Answer 12

71%

Question 13

what % of oceans are deeper than 2000m?

Answer 13

84

Question 14

what is the deepest point in oceans?

Answer 14

11 000m - Mariana Trench
- Challenger Deep

Question 15

what are marginal seas?

Answer 15

semi-enclosed regions affected by local climate
- shallow

Question 16

what are the regions of the oceans?

Answer 16

continental shelf
canyons -> channels sediment movement downwards
abyssal plain -> basic ocean floor
mid-oceanic ridges
shelf-slope break

Question 17

what is the ocean floor made of?

Answer 17

plates

Question 18

are tectonic plates static?

Answer 18

no - constantly moving

Question 19

what forms at ridges?

Answer 19

new crust

Question 20

can the seafloor be dated?

Answer 20

yes

Question 21

what shows polar reversals?

Answer 21

magnetic stripes

Question 22

what is the kind of evidence that suggests that continents were once united?

Answer 22

fossils

Question 23

which hemispheres has more water?

Answer 23

southern - 80% compared to north which has 61

Question 24

what is the Deepsea Challenger?

Answer 24

Cameron got to the bottom of Trench and back in 2h37min

Question 25

is the rate of descent or ascent slower during Deepsea?

Answer 25

descent bc of the pressure under water

Question 26

what are examples of Marginal Seas?

Answer 26

Strait of Georgia Gulf of Mexico Mediterranean Sea

Question 27

what are marginal seas affected by?

Answer 27

- regional climate -> microclimate - precipitation-evaporation balance -> salinity affected - river input of fresh water and dissolved solids -> Hudons' Bay closer to river is less salty - limited exchange with open ocean - geological history -> Salish Sea in Georgia Depression formed by collision of plates

Question 28

what is seafloor spreading?

Answer 28

oceanic crust is formed at ridges, moved laterally and destroyed by subduction, which forms trenches

Question 29

what is a good example of seafloor spreading?

Answer 29

hotspots - regions where the hot mantle rises in stationary plume forming volcanoes

Question 30

where is a hotspot located?

Answer 30

Hawaii - islands are formed by seafloor moving over hotspot - chain of volcanic islands - when crust moves then little volcanoes form

Question 30

what causes continental drift?

Answer 30

continents are embedded in ocean crust so when crust moves then continents move

Question 31

who was the first to figure out theory of continental drift?

Answer 31

Alfred Wegener

Question 31

what are the 4 evidences for continental drift?

Answer 31

- fossils - seafloor mapping/radiometric dating -> seafloor younger than continental crust - magnetic anomalies -> magnetic stripes on ocean floor near spreading ridges show movement of oceanic crust -> Earth's magnetic field switches so polarity becomes opposite

Question 32

what is the strongest bond?

Answer 32

covalent - b/w oxygen and hydrogen and between water and other ions

Question 33

what is a weak bond?

Answer 33

hydrogen - between water molecules - gives sticky properties - creates surface tension

Question 34

what does polarity allow for?

Answer 34

ability to form bonds with other ions

Question 35

does it take a lot of energy to break H bonds?

Answer 35

yes - lots of energy to heat up and lose energy - water has a large thermal buffer capacity and acts like a climate buffer - energy transported by water in ocean currents is large -> water from the S brings heat to the N (water holds onto heat)

Question 36

t or f: water has a low latent heat of fusion

Answer 36

f- highest of all common materials

Question 37

does water hold onto heat?

Answer 37

no - heats and cools faster than adjacent water bodies -> northern land masses do not necessarily experience Arctic climates bc of warm water currents - water transports heat and cold over vast distances -> water from Artic can affect Antarctic waters

Question 38

does deep water have a wide range of temperature?

Answer 38

no 2-4 C

Question 39

does the surface of deep water have a large latitudinal range?

Answer 39

large -1.9 to 40C

Question 40

describe shallow temperate ocean?

Answer 40

Hudsons Bay - thermocline is less drastic in the summer bc water mixes - in winter the water temp is consisten bc the surface is consistent temp

Question 41

why are there latitudinal temperature differences?

Answer 41

- latitudinal gradient of solar heating + - geothermal heating + - internal friction + - water vapor condensation + - back radiation off surface - - convection of heat to atmosphere - - evaporation -

Question 42

what controls salinity?

Answer 42

adds salt by evaporation and sea-ice formation removes salt by precipitation and river runoff

Question 43

what is chlorinity?

Answer 43

grams of chlorine per l of seawater

Question 44

what does salinity =?

Answer 44

1.81 x chlorinity (2 times)

Question 45

how to measure chlorinity?

Answer 45

- chemical titration - conductivity -> most reliable, changes based on temp - index of refraction -> more stuff in ocean them more stuff for light to refract off of

Question 46

what is used to measure salinity in seawater?

Answer 46

CTD- conduction, temp, depth - tests how conductivity varies with temp and depth - conductivity is a measure of salts in water - main salt is chloride

Question 47

what is Principle of Constant Element Ratios?

Answer 47

Forchhammer's Principle - ratio b/w many major elements are constant all over the oceans even though salinity varies - residence time of Na, Cl and Sr is on the order of millions of years -> salts come from river input to the oceans over millions of years - mixing time of water is on order of thousands of years - ocean is mixed well

Question 48

what occurs at mid-latitudes?

Answer 48

excess of evaporation over precipitation

Question 49

what occurs at the equator?

Answer 49

excess of precipitation over evaporation at equator

Question 50

t or f: the maximum density of seawater is at 4C?

Answer 50

F - density influenced by salt and temp

Question 51

when does density increase?

Answer 51

with increasing salinity and decreasing temp

Question 52

what does temp and salinity give rise to?

Answer 52

vertical gradients of density

Question 53

describe shallow water

Answer 53

warm - more saline - less dense

Question 54

describe deep water

Answer 54

cold - less saline - more dense

Question 55

does saltwater freeze at a colder temp than freshwater?

Answer 55

yes

Question 56

what is brinicle?

Answer 56

saltwater sinks, seawater freezes and grows downward, touches the seafloor and kills everything bc it freezes