Exam 3 Flashcards
(135 cards)
1
Q
Where is groundwater present?
A
Where minerals in the crust have pores or fractures
1
Q
What is an aquifer?
A
An underground layer of water-bearing, permeable rock
2
Q
What is an aquitard?
A
An impermeable or low permeability sediment or rock that hinders water flow
3
Q
Where is most freshwater found?
A
In the ground as groundwater
4
Q
What is a water table?
A
A boundary zone which separates unsaturated zones from saturated zones
5
Q
How does the water table rise and fall with the seasons?
A
Water table is higher during wet seasons, and lower during dryer seasons
6
Q
What is porosity?
A
The total volume of open space within sediment or rock
7
Q
What is the difference between primary and secondary porosity?
A
Primary forms within the sediment, while secondary develops later
8
Q
What is permeability?
A
The flow of water due to the connectedness of pore space
8
Q
What is an unconfined aquifer?
A
An aquifer which intersects/ comes in contact with the surface
8
Q
What is a confined aquifer?
A
An aquifer which exists beneath an aquitard
8
Q
What is a disadvantage of an unconfined aquifer?
A
They can be easily contaminated
9
Q
What is Darcy’s law?
A
An equation that describes the flow of a fluid through any porous space
10
Q
What is a recharge area?
A
An area which water permeates the rock into an underground reservoir or an aquifer
11
Q
What is the difference between a connected and disconnected losing stream?
A
The placement of the water table
12
Q
What is hard water?
A
Water with high levels of calcium or magnesium
13
Q
How can deserts be classified?
A
Based on how much rainfall it receives per year (Less than 25 cm)
14
Q
Are deserts always hot?
A
No
15
Q
What is the orographic effect?
A
As the air cools, water precipitates and falls
16
Q
Is climate change normal? What isn’t normal about our sudden increase in climate?
A
Climate change is normal, but the rate of modern-day climate change isn’t
17
Q
How is the heat of the planet controlled?
A
By the oceans
18
Q
What is a major factor that determines where the location of deserts?
A
Atmospheric moisture circulation
19
Q
At what latitudes are deserts found at?
A
30 degrees North, 30 degrees south
20
Q
What are some other factors which contribute to the formation of desserts?
A
Cold ocean currents adjacent to a tropical desert, poor management of farmland, deforestation
21
What is an important geological agent when it comes to the formation of deserts?
Wind
22
What is suspension?
Silt carried in suspension produces well-sorted deposits with distance
23
What is loess?
Silt left by continental glaciers
24
What are desert pavements?
Deposit of sediment after fine grains blow away
25
What is a yardang?
Rock outcrop sculpted by sand abrasion
26
What are some factors which determine how sand dunes are created?
Abundant of loose sediment, energy to move sediment, obstacle to trap sediment and a dry climate
27
How are arid landforms created
They can be shaped by water, thus flash floods are common
28
What are playa lakes?
Products of rainfall and evaporation (usual ephemeral pools of water in a desert)
29
What is desertification?
When land loses its vegetation and turns into a desert
30
What is a glacier?
A thick mass of recrystallized ice, which lasts all year long
31
How are glaciers formed?
Snowfall accumulates and survives the following summer, snow burial causes compaction
32
What are the three conditions to form a glacier?
Cold climate, snow must be abundant (more snow than snow melt), snow must not be removed by other agents
33
What are the two types of glaciers?
Alpine (mountain) and continental (ice sheets)
34
What is the flow of alpine glaciers?
Flow from high to low elevation in mountainous settings
35
How do continental glaciers flow?
Ice flows out from the thickest part of the ice sheet
36
Where are two major ice sheets on Earth?
Greenland and Antarctica
37
How does glacial ice move?
Basal sliding, and plastic deformation
38
What is basal sliding?
Meltwater forms at the base of glacier, water decreases friction as ice slides downwards
39
What is plastic deformation?
Under high pressure, rather than breaking, ice bends much like plastic
40
At what depth does plastic deformation occur?
60 m
41
What factors impact how fast a glacier moves?
Steeper hills, wet bottoms, and greater velocity are seen at the centre
42
What is the zone of accumulation?
The area of net snow addition
43
What is the zone of ablation?
The area of net loss
44
Where does the zone of accumulation and ablation meet?
The equilibrium line
45
What happens when accumulation = ablation?
If ablation and the glacial toe stays in the same place
46
What happens if accumulation > ablation?
The glacial toe advances
47
What happens if accumulation < ablation?
Glacial toe will retreat upslope
48
What is the difference between tidewater glaciers and ice shelves?
Tidewater glaciers are valley glaciers entering the sea while ice shelves are continental glaciers
49
What is sea ice?
Nonglacial ice formed by frozen sea water
50
What is a cirque?
Bowl-shaped basins on a mountain
51
What happens when ice in a cirque melts?
Creation of a tarn (lake)
52
What is an arete?
A mountain formed by the edges of two cirques
53
What is a horn?
Formed by three or more cirques which surround a peak
54
What is a fjord?
U-shaped glacial troughs flooded by the sea
55
What is a hanging valley?
Valley which has been deeply scoured by glacial ice, leaving the tributary valley “hanging” above the main valley
56
What is a roche moutonee?
An asymmetric hill
57
What is (glacial) plucking?
Wind removing sediment from other end of a mountain
58
What do glaciers act like?
Large-scale conveyor belts which pick up, transport and deposit sediment
59
What is the debris at the toe of a glacier called?
An end moraine
60
What is a moraine?
Unsorted debris deposited by a glacier
61
What is a lateral moraine?
A moraine which forms along the side of a valley glacier
62
What is a medial moraine?
A moraine formed from the merging of two lateral moraines
63
What are the different types of glacial sedimentary deposits
Glacial till, erratics, glacial marine sediments, glacial outwash, loess, glacial lake-bed sediment
64
What is glacial till?
Sediments dropped by glacial ice - consists of all grain sizes
65
What is an erratic?
A boulder transported long distances by glacial ice
66
What is a glacial marine?
Sediment from an oceanic glacier
67
What is glacial outwash?
Sediment transported by meltwater - mud is removed while grains are rounded
68
What is a majority of outwash composed of?
Sand and gravel
69
What are glacial lake-bed sediments?
Rock flour settles out of suspension in deep lakes
70
How are kettle lakes formed?
Stranded ice blocks
71
What are drumlins?
Along, align hills of molded till
72
What is an esker?
A long sinuous ridge of sand and gravel
73
What are some consequences of continental glaciation?
Ice loading and sheet rebound, rise in sea levels, the draining of lake Agassiz
74
How stable is the Earth's surface?
It is mostly unstable
75
What is mass wasting?
Downslope motion of rock, soil, sediment, snow and ice
76
How fast can mass wasting occur?
Fast or slow
77
What is mass movement?
Costly natural hazards
78
Why is mass movement important to the ck cycle?
It is the initial step in sediment transport and an agent of landscape change
79
What are the four factors which classify mass movement?
Type of material, velocity of movement, nature of the mass, and movement environment
80
Rank mass movement from slowest to fastest
Creep, slumping, lahars and mudflows, debris flow, and rock slides
81
What is a creep?
A slow downhill movement caused by soil expansion and contraction
82
What is solifluction?
Low downhill movement of tundra
83
What is slumping?
Sliding regolith of coherent rocks
84
What three distinct features does a slump have?
Head scarp, toe, discrete faulted slices
85
What do mudflows, debris flows, and lahars have in common?
They have H2O rich movement
86
Where are mudflows most common?
In tropical settings with rainfall
87
What is the difference between debris/mudflows and lahars?
A lahar can only be classified as such if mud or debris originated from a volcano
88
What are the three types of submarine masses?
Submarine slumps (semicoherent blocks), submarine debris flows (broken materials move as slurry), turbidity currents (Sediment moves as clouds)
89
What are the two dynamic forces in slope stability?
Downslope (gravity) and resisting forces (material strength)
90
Where are larger forces present?
In steeper slopes
91
What is the "Angle of repose"?
Loose granular minerals assume a sloped angle
92
What is loading?
Adding weight to the top of a slope
93
What is angle?
Steepening a slope beyond the angle of repose
94
What changes can affect the strength of a slope?
Weathering (weakens regolith), vegetation (stabilizes slope), water (reduces slope strength)
95
What are several factors which are significant to mass movements?
Relief and climate (more rainfall creates more water-based problems)
96
How can we prevent mass movement?
Geologic mapping, revegetation, terracing etc.
97
What is orogenesis?
Mountain building
98
What are some processes involved in mountain building?
Uplift, deformation, jointing etc
99
What do young mountains look like? What to older mountains look like?
Young mountains are high and steep while older mountains are eroded remnants lowered by erosion
100
What is the difference between undeformed and deformed rocks?
Undeformed beds are horizontal with no folds or faults, deformed beds are tilted with metamorphic alteration and have folds and faults
101
What is strain?
Change in shape caused by deformation
102
What are the three types of strain?
Stretching, shortening, and shearing
103
What are the two major types of deformation?
Brittle and ductile
104
What factors does deformation depend on?
Temperature, pressure, deformation rates, and composition
105
What is brittle deformation and where does it occur?
Rocks break by fracturing and it only occurs in the shallow crust
106
What is ductile deformation and where does it occur?
Rocks deform by flowing and folding, occurs at 10 - 15 km in depth
107
What is compressive stress?
Takes place when object is squished, shortens and thickens material
108
What is horizontal tension?
Occurs when object is pulled apart, lengthening and thinning material
109
What occurs during shear stress?
Surfaces slide past each other, neither thickens or things material
110
What is a strike and a dip?
A strike is a horizontal intersection with a tilted surface, while a dip is the angle of a surface down from the horizontal
111
What is the purpose of joints and veins?
Water often flows through joins and dissolved minerals precipitate through veins
112
What are the three types of faults?
Dip slip, strike-slip, oblique slip
113
What is the difference between a reverse fault and a normal fault? (Dip slip faults)
Reverse fault: hanging wall moves up fault slope
Normal fault: hanging wall moves down fault slope
114
What is a thrust fault?
A reverse fault with a gentle dip
115
How are strike-slip faults classifed?
By sense of motion (Right lateral and Left lateral
116
What is the amount offset by faults called?
Displacement
117
What special terminology is used to describe folds?
Hinge: The curvature
Limbs: Curved side
Axial plane: Connects hinges of the layers
118
What is an anticline?
Fold which looks like an arch
119
What is a syncline?
Fold which opens up like a trough
120
What is a plunging fold?
Has a tilted hinge
121
Where are the oldest rocks located in domes and basins?
Domes: Oldest rock in the centre
Basin: Younger rocks centre
122
What is a flexural slip?
Layers slide past each other
123
When does passive flow form?
In hot, soft and ductile rock at high temperatures
124
What does both horizontal and shear compression do to rocks?
Horizontal compression causes rocks to buckle while shear causes rocks to fold
125
What is a craton and what are the two types?
A crust which hasn't been deformed in 1 GA -- shields and platforms
126
What is the difference between shields and platforms?
A shield is made up of Precambrian metamorphic rocks and igneous rocks -- platforms are shields which are covered by a layer of Phanerozoic strata
127
What is a barchan (Crescentic) dune?
Strong wind in one direction, small sand and limited vegetation
128
What is a transverse dune?
Weak wind in done direction, large sand, perpendicular to wind, limited vegetation
129
What is a parabolic dune?
Arms stabilized by upwind vegetation, semi-circular blowouts that elongate
130
What is a longitudinal dune?
Winds flowing in opposing directions, two slip faces which align with the wind
131
What is the fastest growing dune and why?
Star dunes because of multidirectional wind
