Geology 101 Quiz 11

Question 1

water and weathering

Answer 1

water makes dissolution possible, expanding ice widens cracks, and glaciers can pluck boulders from mountain sides and pulverize them

Question 2

water and erosion

Answer 2

rivers and glaciers transport weathered rock great distances

Question 3

water and rock formation: igneous rock

Answer 3

water lowers the melting temperature and influences the rate of crystal growth

Question 4

water and rock formation: metamorphic rock

Answer 4

water facilitates exchange with dissolved ions (hydrothermal)

Question 5

water and rock formation: sedimentary rock

Answer 5

water transports dissolved and particulate minerals, and creates depositional environments

Question 6

water and volcanism

Answer 6

water affects viscosity of magma and gas pressure

Question 7

water and slope stability

Answer 7

water usually decreases the stability of a slope

Question 8

life is possible in large because

Answer 8

water is liquid in the 0-100*C temperature range

Question 9

unique properties of water

Answer 9

1. melting-boiling temperatures 0-100*C
2. polar molecule
3. solid water is less dense than liquid water
4. unusually high heat capacity

Question 10

water has a ? structure; its peculiar shape results in ?

Answer 10

bent; a negative and positive side

Question 11

the polar nature of water results in

Answer 11

1. dissolution and transport of ions
2. creation of surface tension
3. attraction to sediment particles

Question 12

the polar nature of water and its dissolution and transport of ions means water

Answer 12

increases weathering and assists in moving nutrients in and wastes out of organisms

Question 13

the polar nature of water and the creation of surface tension means water

Answer 13

reduces evaporation rates and creates an entire habitat for surface organisms

Question 14

the polar nature of water and its attraction to sediment particles means water

Answer 14

makes sediment particles stick together and causes capillary rise

Question 15

many nutrients and waste products in organisms are ions, which means they are

Answer 15

easily dissolved and transported into and out of organisms

Question 16

non-polar liquids like gasoline are good at dissolving ?, but not very good at dissolving ?

Answer 16

uncharged organic molecules; charged ions found in minerals

Question 17

polarity creates surface tension because

Answer 17

the negative and positive sides of water molecules align to form weak bonds at the surface

Question 18

one good thing that comes from surface tension is that evaporation is slower - why?

Answer 18

water has to break free from the surface tension to pass into the vapor phase

Question 19

one good thing that comes from surface tension is that water striders can be water striders - how?

Answer 19

surface tension will support the weight of dense objects that will sink if they break through the surface tension; water striders take advantage of surface tension to walk on water

Question 20

capillary rise

Answer 20

water is drawn upward into unsaturated sediments

Question 21

where groundwater is shallow, roots can get water delivered by ? even if the roots do not extend to the water table

Answer 21

capillary rise

Question 22

ice is less dense than water, and therefore floats, because of

Answer 22

the particular arrangement of water molecules in ice

Question 23

water has an unusually high heat capacity, meaning

Answer 23

it takes more heat energy to raise the temperature of water compared to other substances

Question 24

the heat capacity of water plays an important role in

Answer 24

climate control

Question 25

over large bodies of water, heat exchange between the air and water changes the temperature of the ? more

Answer 25

air

Question 26

only about ? of the earth's water supply is available to drink, and most of this is sitting underground

Answer 26

1%

Question 27

despite contamination, we still have water to drink because

Answer 27

water on earth does not exist in a static condition

Question 28

water is continuously cycled and purified through what is called the

Answer 28

hydrologic cycle

Question 29

hydrologic cycle steps

Answer 29

evaporation, condensation, precipitation, infiltration, evapotranspiration

Question 30

transpiration

Answer 30

transfer of water to the atmosphere through leaves

Question 31

if water filled plant cells and stopped, the flow of nutrients would stop - what keeps the water flowing through the plant?

Answer 31

transpiration

Question 32

does water vapor automatically precipitate?

Answer 32

no

Question 33

for precipitation, conditions in the atmosphere have to change to cause the water vapor to condense - this generally happens by

Answer 33

b

Question 34

there are three common ways an air mass gets cooled, but all have to do with

Answer 34

the air cooling as it expands (as an air mass rises, it expands)

Question 35

what are the three common ways an air mass gets cooled?

Answer 35

1. orographic lifting 2. frontal lifting 3. convective lifting

Question 36

orographic lifting

Answer 36

caused by an air flow over mountains

Question 37

rain shadow

Answer 37

dry region on downward side of mountain range because air rising on the upwind side rains out as it rises; as air travels down the far side, it compresses and warms so no more water condenses

Question 38

frontal lifting

Answer 38

caused by moving cold or warm fronts

Question 39

cold front

Answer 39

cold air is more dense, so it ploughs its way underneath warmer air in front of it; as the warmer air rises, it expands, cools, and precipitates

Question 40

warm front

Answer 40

warm air is less dense, so it slides up over the top of the colder air in front of it; as the warmer air rises, it expands, cools, and precipitates

Question 41

convective lifting

Answer 41

caused by heating air near the ground

Question 42

convective lifting is often associated with

Answer 42

cities where building and pavement absorb sunlight and radiate it out as heat

Question 43

water that stays in the ground is known as

Answer 43

groundwater

Question 44

groundwater can be divided into two regions

Answer 44

the saturated zone and the unsaturated zone

Question 45

unsaturated zone

Answer 45

contains air and water in pores (a well in the unsaturated zone will be dry)

Question 46

saturated zone

Answer 46

pores are completely filled with water (a well completed in the saturated zone will fill with water)

Question 47

water table

Answer 47

top of unconfined saturated zone

Question 48

aquifer

Answer 48

a geologic unit that transmits water in sufficient quantity to supply a well

Question 49

confined aquifer

Answer 49

aquifer bounded on top by an impermeable layer

Question 50

artesian well

Answer 50

water rises in a well above the top of the aquifer

Question 51

flowing artesian well

Answer 51

water rises above the ground surface

Question 52

potentiometric surface

Answer 52

the height to which water will rise in a cased well

Question 53

influences on groundwater flow: porosity

Answer 53

ratio of pore volume to total volume (ex: if solid particles fill half the total volume, the porosity is 0.5 or 50%)

Question 54

influences on groundwater flow: permeability

Answer 54

ability of a medium to transmit a fluid (water)

Question 55

we tend to think that higher porosity always leads to higher permeability - is this true?

Answer 55

often, but not always

Question 56

poorly sorted sediments have (lower/higher) porosity and (lower/higher) permeability

Answer 56

lower; lower

Question 57

more compacted, more tightly packed sediments have (lower/higher) porosity and (lower/higher) permeability

Answer 57

lower; lower

Question 58

tightly packed sand has a (lower/higher) porosity than loosely packed clay, and a (lower/higher) permeability

Answer 58

lower; higher

Question 59

if the shape and packing are the same, different grain sizes (do/do not) change the porosity

Answer 59

do not

Question 60

smaller particles will (decrease/increase) permeability and why?

Answer 60

decrease; because of attraction between the water and solid surfaces

Question 61

good aquifers (high porosity and permeability) examples

Answer 61

sand, gravel, sandstone, karst limestone

Question 62

karst

Answer 62

lots of dissolved caves and passageways

Question 63

intermediate to poor aquifers

Answer 63

silt, glacial till, fractured rock, unweathered limestone

Question 64

not aquifers

Answer 64

clay, shale, unfractured crystalline rock

Question 65

one way a spring can form: if water accumulates on an impermeable layer intersected by a slope, water will

Answer 65

eventually seep out the side of the hill slope

Question 66

one way a spring can form: fractures cutting through a confined aquifer will

Answer 66

provide conduits for pressurized water to reach the surface

Question 67

when we start to pump water from a well, what happens to the water table or potentiometric surface?

Answer 67

a cone of depression (drawdown cone) forms

Question 68

if pumping from multiple wells exceed annual recharge, the entire water table will begin to ?, which increases pumping costs and can cause ?

Answer 68

lower; wells to go dry and the ground surface to subside

Question 69

subsidence

Answer 69

decrease in surface elevation due to collapse or compression of underlying material

Question 70

subsidence in unconfined aquifers: draining water from unconsolidated sediments often causes ?, so the ground surface settles downward

Answer 70

compaction (compacted sediments take up less space)

Question 71

subsidence in confined aquifers: confined aquifers are ?, but pumping relieves pressure, which allows the aquifer to ?

Answer 71

pressurized; compress (the ground surface drops)

Question 72

subsidence in caves

Answer 72

a cave with a thin or weak roof may collapse if pumping drops the water level below the top of the cave

Question 73

a depression or hole caused by a collapsed cave roof is called

Answer 73

a sinkhole

Question 74

total dissolved solids (TDS)

Answer 74

the total mass of all dissolved ions and molecules per liter of solution

Question 75

we divide water into different types based on TDS:

Answer 75

fresh, brackish, saline, brine

Question 76

water in quartz sand (SiO2) tends to have (low/high) TDS< with dissolved ? as primary ion

Answer 76

low; silica

Question 77

water in limestone (CaCO3) is fresh, but tends to have (lower/higher) TDS, with ? and ? as primary ions

Answer 77

higher; calcium and bicarbonate

Question 78

water in halite (NaCl) forms a brine, (very low/very high) in TDS, with ? and ? as primary ions

Answer 78

very high; sodium and chloride

Question 79

contaminants come in a variety of different forms

Answer 79

salts, metals, bacteria, agricultural and pharmaceutical chemicals, radioactive waste, organic liquids

Question 80

organic liquids are divided into two groups

Answer 80

LNAPL and DNAPL

Question 81

LNAPL

Answer 81

light non-aqueous phase liquid (floats on water)

Question 82

DNAPL

Answer 82

dense non-aqueous phase liquid (sinks in water)

Question 83

Which are harder to clean up and why? (LNAPL or DNAPL)

Answer 83

DNAPL because they continue moving downward in an aquifer and get hung up in little pools wherever the permeability is slow