Glg 121

Front 1

What is the hydrologic cycle?

Back 1

Hydrologic cycle: the cycle through which water in the hydrosphere moves.

Front 2

What are the main reseviors and the directions and relative magnitudes of the fluxes between these reseviors

Back 2

Several reservoirs: oceans (97%), glaciers, groundwater, surface water, biosphere, soil moisture, and the atmosphere.
Includes processes (fluxes) such as evaporation, precipitation, surface runoff and groundwater flow.

Front 3

What is residence time and how is it calculated?

Back 3

Residence time = size of reservoir / rate of influx.

Front 4

What is a stream? What is a drainage basin?

Back 4

Stream: flowing water in a channel.
Drainage basin (or watershed): the region from which surface water drains into a particular stream

Front 5

Defense of Property (D/P)

Back 5

Defense of property requires that someone be able to use reasonable force to prevent the commission of a tort against her or her personal property (though she cannot cause death or substantial bodily harm).

- Request to desist unless futile
- Doesn't continue, ends w/ tort
- Not available w/ person w/priv
- Mistake NOT allowed re: privilege, unless D r/ably believes no priv bc of P conduct
- No DF unless invasion = serious threat of bodily harm

Front 6

What is discharge and how is it calculated?

Back 6

the amount (volume) of water flowing past a given point over a particular time interval, (m2) (m/s) = m3/s

Front 7

What is alluvium?

Back 7

general term for particulate stream sediment

Front 8

What are the four ways in which streams carry sediment?

Back 8

bed load, saltation, suspended load, dissolved load

Front 9

What is stream capacity and what factors exert the principal controls on it?

Back 9

Stream capacity: how much material a stream can carry as total load --depends upon: Discharge: more and faster water can move more sediment
and Sediment availability: compare alluvium and bedrock stream beds.

Front 10

What is the difference between active and passive continental margins with respect to the types of coastlines that develop at each?

Back 10

Active: cliffs above the waterline, narrow continental shelf and steep drop to oceanic depths offshore. Passive: broad continental shelf and broad beaches/sandy offshore islands

Front 11

What is a wave? What are wave fronts and wave normals?

Back 11

Wave: energy moving through water.
Wave fronts = lines along crest
Wave normals = lines perpendicular to fronts - show wave travel direction

Front 12

What are the three factors that control the size of waves?

Back 12

wind velocity, duration of wind activity and distance over which wind blows (fetch)

Front 13

How do shapes of waves and trajectories of water movement within waves change as they enter shallow water?

Back 13

Near coastline, friction between bottom and wave causes elliptical wave trajectories (asymmetrical wave shape).

Front 14

What are wave refraction and longshore drift?

Back 14

Wave refraction: bending of wave fronts as one part of wave reaches shallow water (and thus slows down) before another part.
Longshore drift: Transportation of sediment along the beach

Front 15

What is the gradient of a stream?

Back 15

the slope (steepness) of a stream channel

Front 16

What is a beach?

Back 16

gently sloping surface washed over by waves and covered by sediment (usually sand or gravel)

Front 17

What are barrier islands?

Back 17

narrow, flat, long (up to 100 km) islands of sand parallel to coast

Front 18

What is a spit? What is a sea cliff?

Back 18

Spit: finger-like ridge of sediment extending into deeper water due to longshore currents (ex: cape cod)

Sea cliff: created by wave erosion of stronger materials.

Front 19

How does a gradient change over the length of a typical stream and how does this affect size of the material it can carry?

Back 19

Gradient typically decreases downstream (overall)

Front 20

What is a graded stream and how do base level changes affect a stream?

Back 20

Graded stream: a stream showing a balance between its transporting capacity and the amount of material supplied to it
Closer to base level, streams flows more slowly

Front 21

What is a braided stream? A bedrock stream? A meandering stream?

Back 21

Braided: numerous intertwining channels
Bedrock: channel is carved into bedrock
Meandering: single sinuous channel

Front 22

What are the various feature of a meandering stream?

Back 22

Meanders, cut bank, point bar, thalweg, sinusoity, cut off meander, oxbow lake, floodplain

Front 23

Why does groundwater represent such an obvious source of fresh water?

Back 23

1) Abundance - Largest reservoir of unfrozen fresh water
2) Ubiquity - Often present even where there is little surface water
3) Purity - Flow through granular material tends to rid water of bacterial contaminants
4) Quality - More consistent than that of surface water

Front 24

What is an aquifer?

Back 24

Aquifer: Rock or unconsolidated deposits that are sufficiently porous and permeable to be useful as a source of water.

Front 25

What are the zone of saturation, the zone of aeration and the water table?

Back 25

Zone of saturation: where pore spaces are completely filled with water (phreatic zone)
Zone of aeration: where pore spaces contain soil moisture and soil gas (vadose zone)
Water table: the top of the zone of saturation

Front 26

What are porosity and permeability?

Back 26

Porosity: voids in soil, sediment, or rock.
Permeability: a measure of how readily fluids pass through porous material – interconnectedness of pore spaces is the main control.

Front 27

What is karst and how is groundwater flow different in karst aquifers than in sand and gravel aquifers?

Back 27

Karst: a type of landscape that is formed over soluble rocks and is characterized by sinkholes, caves, disappearing streams, and rapid underground drainage
Lack of filtration by granular materials results in higher potential for groundwater quality problems in karst areas

Front 28

What weak acide is responsible for the dissolution of bedrock in most karst areas and what is its source/

Back 28

Carbonic acid and it forms when occurs when rain water absorbs atmospheric carbon dioxide (CO2) and when infiltrating groundwater absorbs bacterially-produced CO2 from soil gas.

Front 29

What is a cone of depression and why does it occur during pumping of groundwater?

Back 29

a broadly conical depression of the water table or potentiometric surface caused by pumped GW withdrawal.

Front 30

What are the most common results of over pumping of groundwater?

Back 30

water table decline, reversal of water table slope, subsidence, saltwater intrusion and sinkhole formation

Front 31

What are the common measure of water quality?

Back 31

Dissolved ions, biological populations, synthetic chemicals

Front 32

From where does Oxford obtain its water?

Back 32

Four Mile Creek Valley Aquifer and the Seven Mile Creek Aquifer.

Front 33

What is a buried glacial valley and how does one form?

Back 33

Buried outwash valleys contain mostly sand and gravel that transmit and filter groundwater very well. They form when glaciers melt into valley and water and sediment are left behind.

Front 34

What are fossil fuels? What is the ultimate source of most of the energy at the earth's surface?

Back 34

combustible deposits of altered organic material that originated through the slow transformation of the remains of ancient plants and animals.
Electromagnetic radiation from the sun is the ultimate source of energy.

Front 35

Why are fossil fuels considered non-renewable?

Back 35

Because they are limited amounts of it on earth.

Front 36

What is petroleum and from what and how does it form?

Back 36

Petroleum = “rock oil”: crude oil and natural gas formed from the remains if microscopic marine organisms

Front 37

What are tar sands and oil shales?

Back 37

Tar sands: Sediments saturated with asphalt-like dense hydrocarbons
Oil shale: Fine-grained clastic rock (shale-like) contains solid waxy material called kerogen.

Front 38

What is coal and from what and how doesi it form?

Back 38

Coal: a readily combustible, hydrocarbon-rich rock formed from the compaction and heating of plant remains

Front 39

Where and when did most of the world's coal form?

Back 39

Most coal is from Carboniferous Period (360 to 290 Ma) because abundant warm tropical coastal locations and sea level changes due to glacial fluctuations

Front 40

Which do we have more of, petroleum or coal?

Back 40

Coal

Front 41

Which burns more cleanly, petroleum or coal?

Back 41

Petroleum

Front 42

What "ingredients" in coal contribute to acide mine drainage and acid rain?

Back 42

Sulfur and nitrogen create acids that cause acid rain and acid mine damage

Front 43

What are some alternative energy sources?

Back 43

Nuclear fission, gas hydrates, nuclear fusion, solar power, hydropower, biomass, geothermal, wind power, fuel cells

Front 44

Which alternative energy sources are renewable? Which ones are non-renewable?

Back 44

Non renewable: nuclear fission, gas hydrates. Renewable: nuclear fusion, solar, hydropower, geothermal, biomass, windpower, fuel cells

Front 45

Which alternative energy source is probably the best "bet" for the long run?

Back 45

Solar

Front 46

How are unconfined and confined aquifers different from each other?

Back 46

An unconfined aquifer is not overlain by an aquitard, and thus receives recharge over its entire extent.
A confined aquifer occurs when a permeable layer is sandwiched between less permeable layers.Recharge occurs only where the permeable layers exposed at the surface

Front 47

What is recharge and how does it occur?

Back 47

Recharge: replenishment of groundwater by infiltration of surface water

Front 48

Why is industry considered the largest water user, but agriculture is the largest water consumer?

Back 48

Because industry uses non consumptive water use in which the water used is returned to the source it came from whereas agriculture uses consumptive water use.

Front 49

What are some ways that water loss due to agricultural use can be decreased?

Back 49

Drip irrigators and improved delivery systems have reduced evaporative and leakage losses by up to 95%
Relying less on livestock for food would reduce water demand

Front 50

What are meteroids, meteors and meteorites?

Back 50

Meteoroid: a sand to boulder-sized particle of debris in the Solar System.
Meteor (shooting star): very small (commonly ~1 mm, but always <1 m) pieces of rock or metal that are heated to incandescence and vaporize (due to frictional heating) upon traveling through Earth's atmosphere
Meteorite: a piece of space rock or metal that passes through the atmosphere to collide with Earth.

Front 51

What are primitive (stony) and evolved (iron) meteorites?

Back 51

Primitive (aka Chondritic) – parent body did not experience differentiation
Evolved (aka Nonchondritic) – parent body experienced differentiation

Front 52

Describe the appearance and origin of primitive meteorites

Back 52

Primitive meteorites are similar in composition to the igneous rocks of Earth's mantle (ultramafic), containing lots of olivine and pyroxene.
Parent bodies were too small to undergo sufficient heat accumulation for differentiation no changes since formation.

Front 53

Describe the appearance and origin of evolved meteorites

Back 53

Parent bodies were fragmented by post-differentiation collision(s)
Very similar in composition to Earth's core (iron + nickel)
Typically have blackened outer crust from frictional heating and surface melting during entry into Earth's atmosphere

Front 54

How might meteorites impacts be associated with the origin of life on Earth? How are thye connected to mass extinction events?

Back 54

Meteorite impacts caused several mass extinctions during Earth history.
Perhaps helped with origin of life as some meteorites (carbonaceous chondrites) contain protein-related amino acids, building blocks of life

Front 55

How much meteorite matieral "hits" the earth everyday?

Back 55

Every day approximately 100 tons of meteorites strike Earth's atmosphere (10 large dump truck loads).

Front 56

How does the behavior of small (<1m) meteoritc particles differ from that of larger (>1m) ones?

Back 56

Most are small enough (<1 m) to be vaporized by frictional heating as they fall through atmosphere.
Larger objects (>1 m & >350 tons) are not slowed and hit Earth with very high speed (80,000 km/hr), producing impact crater.

Front 57

What are the predicted effects of a 10 km meteorite impact and how often do we expect such events?

Back 57

10-km meteorite impact would be the ULTIMATE global natural disaster and result in mass extinction, perhaps including humans.
But collision of 10-km meteorite probably occurs only every 100 m.y.
Effects: tsunami, massive earthquake, melting of large part of crust, possibly acid rain and global warming

Front 58

What size of a meteorite could destroy an entire nation?

Back 58

1-km meteorite can devastate most nations.

Front 59

What size meteorite could destroy a large city?

Back 59

50-100 m objects could level whole cities.

Front 60

How might we prevent a significant impact from occurring? Are we close to having this capability at present?

Back 60

First need to detect and track near earth objects (NEOs)
Then would need to change the orbit of any NEO on a collision course with Earth.
Yes, but we would probably need much advance warning (~10 yr)

Front 61

What are tekites?

Back 61

Tektites: small glassy pieces produced by melting of rock during impact.

Front 62

What happened in Siberia (Tunguska) in 1908?

Back 62

Massive fireball streaked across sky, causing explosion and incredible blast of heat
Sound from explosion heard several hundred km away
Trees over >1,000 km2 destroyed and charred on one side
No crater

Front 63

Why is Serpent Mound in Ohio thought to be an impact crater?

Back 63

The Serpent Mound structure has the characteristics of an impact structure, including a central uplift surrounded by a ring of lower elevation, and then an outer uplifted ring.

Front 64

Where do streams get their water?

Back 64

Direct precipation, surface runoff and groundwater

Front 65

How do we calculate recurrence levels

Back 65

Data needed = maximum daily discharge data for each year over at least 10 years.
T = (N + 1) / M; where:
t=total number of years of data
m=rank of discharge event of interest

Front 66

How do beaches change from winter to summer?

Back 66

Summer: gentle winds lead to less energetic waves that tend to move the sand back onto the beach
Winter: Stronger winds create larger waves that tend to remove sand from the beach and into deeper water

Front 67

Describe seawalls and groins and What are the problems with these coastal eriosion mitigation methods?

Back 67

Seawalls: onshore walls of concrete or rock debris (riprap) Problems--Often fail as wave energy goes around sides or is reflected downwards, Also cuts off sediment supply
Groins: walls of concrete, rock, wood, or sandbags built perpendicular to beach in order to trap moving sand and to hinder sand loss. Problems--Usually successful on upcurrent side, but cuts off sediment supply on downstream side

Front 68

Describe jetties and breakwaters and what are the problems with these coastal eroison mitigation methods?

Back 68

Jetties: pairs of long groins placed on either side of the mouth of a harbor, river mouth, etc. Problems -- Because of their usually greater length, jetties can completely cut off sand migration to the beach
Breakwaters: offshore walls parallel to coast. Problems -- quiet water causes deposition and this requires an endless cycle of removing sediment

Front 69

Describe beach replenishment

Back 69

Beach Nourishment: bringing sediment to the beach to replace the sand that is lost to the waves

Front 70

What are the most effective solutions to coastal erosion?

Back 70

Move buildings and roads back to safer locations, Use vegetation to help stabilize sand dunes behind beaches. No new dams on rivers that discharge into coastal areas with erosion problems,
Do not modify the beach by clearing driftwood, etc., and mining sand/gravel from beaches should be prohibited,Remove and prohibit buildings from cliff tops

Front 71

What is an alluvial fan, how does it form and why are they not good areas from development?

Back 71

Alluvial fan is a fan shaped deposit of sand and gravel at the mouth of a mountain canyon. where the stream gradient flattens at the main valley floor.
Where the mountain side intersects the valley floor,it reaches a local base level of the larger valley. This loss of slope causes water to slow, which in turn causes the deposition if sediment. The locus of deposition changes over time to distribute the sediment in a fan-shaped deposit, Alluvial fans should not be developed on, potential for debris flows.

Front 72

How do meanders form?

Back 72

Start where stream channel is slightly easier to erode. Outsides of bends experience preferential erosion, whereas the insides of bends have deposits.

Front 73

What is a hydrograph?

Back 73

a plot of discharge vs. time.
Higher discharge is usually caused by large precipitation events or snowmelts, especially when the ground is saturated

Front 74

What are some typical flood control measure?

Back 74

Channelization: modify the stream channel to increase the amount of water it can “handle”.
Levees: artificial banks on the side of a river channel.
Dams: control the amount of downstream flow.
Restrictive zoning, retention ponds