Exam 2 Flashcards
(234 cards)
1
Q
A map of the distribution of earthquake epicenters would most closely resemble a map of A. magnetic anomalies B. plate boundaries C. shorelines D. all of the above
A
B) Plate boundaries
2
Q
The earliest known evidence for continental drift was A. seafloor magnetic anomalies B. the jigsaw puzzle fit of continental margins C. the existence of oceanic ridges D. the global distribution of earthquakes
A
B Jigsaw puzzle fit of continental margins
3
Q
What is the relationship between age and the character of the ocean floor? Which statement is TRUE? A. Deeper regions of the ocean floor tend to be younger B. The Pacific is larger than the Atlantic because it contains older oceanic floor C. Oldest oceanic crust is only present near trenches D. Youngest oceanic crust is near the ridges
A
D) Youngest oceanic crust is near the ridges
4
Q
Divergent plate boundaries have mainly A. reverse faults and basalt flows B. normal faults and andesite flows C. normal faults and basalt flows D. reverse faults and andesite flows
A
c) normal faults and basalt flows
5
Q
Convergent plate boundaries have mainly A. reverse faults and basalt flows B. normal faults and andesite flows C. normal faults and basalt flows D. reverse faults and andesite flows
A
D) reverse faults and andesite flows
6
Q
Review the map of the plates and answer the following question. The ocean floor becomes progressively ______ moving from the east coast of South America toward location L.
A) Older
B) Younger
A
B) Younger
7
Q
This is part of a magnetic profile across an oceanic ridge system. The profile shows both positive and negative magnetic anomalies. Based on the symmetry of the patterns, where is the axis of the ridge located?
A
D
8
Q
The schematic cross sections (a to d) illustrate four models of relative plate motions and plate boundary geometry. Which of the cross sections best represents the characteristics of the plate boundary at location 9?
A
B
9
Q
The schematic cross sections (a to d) illustrate four models of relative plate motions and plate boundary geometry. Which of the cross sections best represents the characteristics of the plate boundary at location 8?
A
D
10
Q
Which of the schematic diagrams below best represents mantle convection associated with plate tectonics?
A
A
11
Q
Examine the map and answer the question that follows. How many plates are present?
A) 3
B) 4
C) 5
D) 6
A
C) 5
12
Q
Examine the diagram to the right that shows oceanic and continental crust surrounding a plate boundary. Based on the current plate tectonic setting, location X is moving toward ____?
A
B
C
D
A
C
13
Q
A and B are located on two plates separated by a transform boundary (see diagram below). What direction is plate B moving given that plate A is moving northeast (NE)?
A. northeast
B. northwest
C. southwest
D. southeast
A
C) Southwest
14
Q
During the strain accumulation phase of the earthquake cycle,
A. rocks are deformed elastically.
B. major seismic activity occurs.
C. the major release of elastic deformation occurs.
A
A) rocks are deformed elastically
15
Q
Earthquakes occur in the .
A. mantle
B. lithosphere
C. inner core
D. outer core
A
B) lithosphere
16
Q
The S-wave (or shear wave) is the seismic wave that
A. travels through solids
B. travels through both solids and liquids
C. travels fastest
D. travels slowest
A
A) travels through solids
17
Q
Surface waves are produced by
A. faults rupturing the Earth’s surface.
B. the absorption of S-waves by a liquid medium.
C. the reverberating effects of buildings shaking in response to high frequency P-waves.
D. P-waves and S-waves reaching the surface.
A
D) P-waves and S-waves reaching the surface
18
Q
What determines the magnitude of an earthquake
A. the type of plate boundary where it occurs
B. the amount of damage
C. the amount of energy released by the movement of the rocks
D. the depth of the focus
A
C) the amount of energy released by the movement of the rocks
19
Q
How does earthquake magnitude differ from intensity?
A. Magnitude is a result of the amount of shaking, which is determined by intensity
B. The two terms are the same, referring simply to the size of an earthquake
C. Intensity reflects energy release, while magnitude reflects the amount of shaking
D. Magnitude reflects energy release, while intensity reflects the amount of shaking
A
D) Magnitude reflects energy release while intensity relects the amount of shaking
20
Q
The primary effect of earthquakes that causes damage is
A. tsunamis
B. landslides
C. ground cracking
D. ground shaking
A
D) Ground shaking
21
Q
According to this figure, which of the following is true, given that all other conditions in an earthquake are the same?
A. Hard igneous rock shakes more than sedimentary rock.
B. Sedimentary rock shakes more than alluvium.
C. Alluvium shakes more than silt and mud.
D. Alluvium shakes more than sedimentary rock.
A
D) Alluvium shakes more than sedimentary
22
Q
Faults which lock or stick will
A. never produce earthquakes
B. accumulate strain until a large earthquake occurs
C. creep slowly and produce only small earthquakes
D. deform in a plastic fashion
A
B) accumulate strain until a large earthquake occurs
23
Q
Which of the following statements is false?
A. Seismic gaps indicate areas in which strain is accumulating
B. Soil liquifaction is a precursor of a large earthquake
C. Tsunamis are the most devastating effect of submarine earthquakes
D. Ground amplification is caused by differing geologic materials
A
B) Soil liquifaction is a precursor of a large earthquake
24
Q
Why are most active volcanoes associated with plate tectonic boundaries?
A. Plate tectonic boundaries are created by volcanism.
B. Spreading or sinking plates interact at plate boundaries with other materials to produce magma.
C. Earthquakes at plate boundaries bring large amounts of magma to the surface.
D. In reality, most volcanoes are in the plate interiors rather than at plate boundaries.
A
B) Spreading or sinking plates interact at plate boundaries with other materials to produce magma
25
Viscosity of a magma is determined by
A. temperature and silica content
B. the type of volcanic eruption
C. the size of the eruption
D. all of the above
A) temperature and silica content
26
Intermediate magma (andesitic) can be produced by partial melting of
A. granite
B. peridotite
C. basalt
D. rhyolite
C) Basalt
27
How explosive a volcanic eruption is depends on
A. the viscosity of the magma
B. the amount of dissolved gases
C. the duration of the eruption
D. both A and B
E. A, B, and C
B) both A and B; viscosity of magma and amount of dissolved gases
28
Shield volcanoes:
A. form in continental rift zones
B. form along transform faults
C. form at subduction zones
D. form over mantle "hot spots"
D) form over mantle hot spots: THINK HAWAII
29
Mt. Jefferson in the Cascades, pictured to the left, is composed of andesitic (intermediate) lava flows and pyroclastic material. It is an example of what type of volcano?
A. shield volcano
B. composite volcano (stratovolcano)
C. cinder cone
D. volcanic dome
B) composite volcano(stratovolcano)
30
When a stratovolcano erupts, most damage results from ?
A. toxic gas emissions
B. pyroclastic flows and floods in valleys
C. fast-moving lava flows
D. extensive lava flows
B) pyroclastic flows and floods in valleys
31
Seismic activity serves as a tool of volcanic forecasting because
A. moving magma causes earthquakes.
B. earthquakes and dangerous volcanoes are both associated with subduction zones.
C. seismic activity indicates emission of volcanic gases.
D. earthquakes usually cause the volcanic summit to collapse, setting off an eruption.
A) moving magma causes earthquakes
32
Why is topographic monitoring sometimes useful in forecasting a volcanic eruption?
A. A volcano sometimes swells as lava moves into the upper magma chamber.
B. Volcanic eruption is more likely as an area undergoes tectonic uplift.
C. Seismic activity occurs as the volcano rises.
D. Topographic monitoring reveals the likelihood of mudflow generation.
A) a volcano sometimes swells as lava moves into the upper magma chamber
33
Where would be the safest location to build a volcano observatory?
A. Top of a composite volcano
B. Top of a shield volcano
C. Top of a cinder cone
B) top of a shield volcano
34
The zone of leaching in a soil profile contains which soil horizons?
a) A and B
b) A and E
c) B and C
d) A, B, and C
B) A & E
35
The B-horizon of a soil
a) contains most of the organic matter in the soil
b) is where leaching is most effective
c) is where secondary minerals are deposited
d) all of the above
C) is where secondary minerals are deposited
36
Which of the following climates will lead to the development of the thickest soil profiles?
a) high rainfall & high temperature
b) high rainfall & low temperature
c) low rainfall & high temperature
d) low rainfall & low temperature
A) high rainfall and high temps
37
Soil development is slowest in
a) warm, humid climate
b) warm, dry climate
c) cool, humid climate
d) cool, dry climate
D) cool, dry climate
38
The USDA soil classification system (soil taxonomy) is based on
a) the processes that formed different soils.
b) physical and chemical properties of the soil profile.
c) divisions and subdivisions of soil texture.
d) the organic matter content of the B horizon.
B) physical and chemical properties of the soil profile
39
Which arrow represents nitrogen fixation by plants?
a) arrow 1
b) arrow 2
c) arrow 3
d) arrow 4
Atmosphere |
| 1 |
biosphere | 4
| 2 | 3 |
Soil zone ------ |
A) Arrow 1
40
Weathering processes are primarily responsible for the concentration of what type of ore?
a) gold
b) cadmium
c) aluminum
d) copper
C) aluminum
41
In what ways are soil surveys useful for land-use planning? In what ways are soil surveys useful for
land-use planning?
a) They provide the basis for rating limitations for specific land uses.
b) They provide maps showing the shrink-swell potential of soils.
c) They provide the basis for determining land valuation.
d) They show where existing soils have been covered by urbanization
A) they provide the basis for rating limitations for specific land uses
42
The portion of rainfall that flows off the land and directly into a river is called
a) watershed
b) flood magnitude
c) baseflow
d) overland flow
D) overland flow
43
What is the discharge of a stream in a rectangular channel that is 10 meters wide, 6 meters deep, 40 kilometers long, and has a velocity of flow of 5 meters per second?
a) 21 cubic meters per second
b) 300 cubic meters per second
c) 1200 cubic meters per second
d) 2400 cubic meters per second
B) 300 cubic meters per second
44
A stream channel is narrowed by bridge construction. How will the velocity of flow change if the depth and discharge of the stream remain constant?
a) velocity will increase
b) velocity will decrease
c) velocity will not change
A) velocity will increase
45
The gradient of a stream is
a) the volume of water passing a point per unit time
b) the product of velocity times width times depth
c) steepest near the stream's head (upper end)
d) steepest near the stream's mouth (lower end)
C) steepest near the streams head
46
What is river base level?
a) the lowest level to which a river may erode
b) the river discharge that is maintained year round
c) the elevation of the stream bed
d) the smallest amount of sediment a stream can transport
A) the lowest level to which a river may erode
47
Silt and clay are transported by streams primarily as ?
a) dissolved load
b) suspended load
c) bed load
B) suspended bed load
48
Which of the following statements about infiltration and overland flow is **false**?
a) the presence and type of vegetation do not affect the rate of infiltration
b) permeability is one factor controlling the rate of infiltration
c) overland flow occurs when the rainfall rate exceeds the infiltration capacity of a soil
d) overland flow is necessary for flooding to occur
A) the presence and type of vegetation do not affect the rate of infiltration
49
What is the best description of the "10-year flood?"
a) a flood that can occur only once every 10 years
b) a flood that has a 10% chance of occurring each year
c) a flood that occurred within the last 10 years
d) a flood that lasts for approximately 10 years
B) a flood that has a 10% chance of occurring each year
50
Consider the effects urbanization on streams. Which of the following is true?
a) overland runoff and peak discharges will increase
b) overland runoff and peak discharges will decrease
c) lag time from rain event to flood peak will increase
d) lag time from rain event to flood peak will decrease
e) both a and d
E) both a and d; overland runoff and peak discharges will increase and lag time from rain event to flood peak will increase
51
In what way can structures designed to control floods (like dams and levees) actually increase flood damage?
a) by decreasing impervious cover in the urban environment
b) by increasing runoff in the upper portions of drainage basins
c) by encouraging development on the floodplain
d) by making the water transmitting capacity of the stream less efficient
C) by encouraging development on the floodplain
52
Ocean floor is all younger than:
200 million years
53
Sea floor spreading:
Ocean ridges are zones of weakness
Magma rising from the uppermantle, erupts at mid-ocean ridges and new crust is created
Seafloor moves laterally away from the ridge
As new seafloor moves away from the ridge, it cools and becomes denser
54
Where do earthquakes occur
At plate boundaries
55
Ocean crust is created at?
Mid-ocean ridges
56
At subduction zones, ocean crust descends back into the mantle and...
is destroyed
57
The major driving force in transforming rocks:
Earth's internal heat
58
Theory of Plate Tectonics
Earths outer layer is broken up into rigid plates that are in motion because of forces associated with planets interior heat
59
Deformation involves shape or volume called:
Strain
60
3 types of stress:
Compression
Tension
Shear
61
What type of stress pushes on rocks from opposite directions causing them to shorten?
Compression Stress
62
What type of stress pulls on rocks from opposite directions resulting in the rocks becoming stretched or lengthened?
Tension Stress
63
What type of stress is when rocks are squeezed in an uneven manner causing them to become skewed such that different sides slide or move in opposite directins?
Shear Stress
64
What is the elastic limit?
Point beyond which they no longer behave elastically and deformation becomes permanent
65
Fracturing is when a rock becomes brittle and will
snap in two
66
Flowing/Ductile is when a rock will:
bend permanently (plastic deformation)
67
When rocks deform and slide past each other along the fracture plane, this is known as a
FAULT
68
Rocks near the surface are:
Brittle and will fracture
69
Rocks buried deep are:
Ductile and deform plastically
70
Super continent was named
Pangaea
71
What is a midocean ridge
A chain of submerged mountains
72
What is an abyssal plain
Deep, flat portions of the ocean
73
Why doesnt the earth get bigger with sea floor spreading?
Subduction zone recycling
74
What refers to the processes associated with the creation, movement, and destruction of lithospheric plates?
Plate Tectonics and Earth's Systems
These processes produce landorms such as ocean basins, continents, and mountains
75
What are PLATES
Rigid slabs of lithosphere
76
What are plate boundaries?
Where plates slide past, override, tear, and smash into each other
77
Plate tectonics is driven by?
Mantle convection
78
Lithosphere is divided into how many plates?
7 major and several minor plates
79
A Divergent Boundary is where
2 plates are moving away from each other (TENSION)
80
A Convergent boundary is where
2 plates move towards each other (compression stress)
ex: subduction zones where plates collide
--High seismic activity
--Low heat flow because cold slab of lithosphere is being pulled down into asthenosphere and chills asthenosphere
\* 3 types: Ocean/Ocean, Ocean/Continent, Continent/Continent
81
A Transform boundary is where
2 plates slide past each other (SHEAR stress) (San Andreas Fault)
--High seismic activity
--Low heat flow
--No creation or destruction of Lithosphere
\*EQs are generated by LATERAL SHEAR of rocks
\*\*Most transform boundaries are in oceans
82
Ocena/Ocean Convergent Boundaries
Older, denser ocean lithosphere subducts; younger less dense ocean lithosphere is overriding plate
- Oceanic lithosphere is destroyed
- Develop deep ocean TRENCH
- Develop Island Arc or Volcanic Area
--Get Andesitic and Rhyloitic Lava
83
Felsic
|
Rhyolite Magma
\*Intermediate
|
Andesite Magma
\*Mafic
|
Basalt Magma
Felsic creates Rhylotic Lava
Intermediate creates Andesitic Lava
Mafic creates Baslatic Lava
84
Ocean/Continent:
Ocean lithosphere subducts; continental lithosphere is overriding plate
Similar characteristics as ocean/ocean
Ocean lithosphere destroyed, intermediate to felsic volcanoes
Develop a mountain Arc: Basically a chain of volcanoes on continent (West coast cascade mountains)
85
Continent/Continent
Develop continental suture
Neither plate subducts, both too buoyant--push up MTN ranges
Seismic activity but no volcanism
Area of much metamorphism
EX: Himalayan Mts
86
EQ's happen primarily along
Plate boundaries
87
How EQ's occur:
Stress causes deformation (strain)
88
Elastic Strain
Deformation isnt permanent as long as strain is released
89
Elastic limit
Deformation past this point leads to permanent deformation
90
What is a rupture in a rock?
Breaking of brittle rock
91
What is rebound?
Broken ends snap back releasing their pent up energy (source of seismic waves)
92
Seismic waves:
Vibration waves that travel via Earth materials
93
Seismograph:
Instrument to measure seismic waves
94
The Focus of Hypocenter
Point of rupture within the earth
95
Epicenter of an EQ
Point directly above focus on Earth surface
96
What are Body Waves?
Waves that travel through Earth's interior; tell us about the internal structure of Earth
97
P-Waves or Primary Wave Characteristics:
Travel through solids and liquids
Travel fastest (primary), the waves compress and extend the earth, speed is a function of rock density and rigidity
98
S-Wave or Secondary Wave characteristics:
Travels through solids ONLY (shear wave)
arrives SECOND, 2/3 of speed of p-wave, moves in all directions perpendicular to wave advance
Speed is also a function of rock density
Both waves start at the same time, S wave is just slower
Moves up and Down
99
Surface waves:
Travel at the Earth's surface like waves on water surface
100
Surface waves characteristics:
Travel slowest, Rayleigh waves have Rolling motion and Love wave is more sideways motion
101
How to locate an EQ
Determine time of arrival of P and S waves at seismographs
Calculate the distance from seismograph to the epicenter based on lag times (s-wave behind p-wave)
Need seismograph data from at least 3 locations to determine epicenter location
Locating the focus is more complex
102
EQ Intensity is:
How people perceived and structures responded to the ground shaking
103
EQ intensity ranges are from:
I-XII (1-12)
104
Magnitude
Magnitude is an estimate of the approximate energy released by an EQ source
105
Richter Magnitude is calculated by
measuring the maximum amplitude of ground motion from seismograph records, corrected for distance from the source
-Logarithmic scale (each unit indicates 10 times more ground motion than previous number)
100 = 1
101= 10
102 = 100
103 = 1000
106
Moment Magnitude
Based on the dimensions of the fault plane that ruptured, the amount of movement and the rigidity of the rocks
- Method of determining magnitude preferred by scientific community
- Magnitude is the same no matter where its recorded
\*better estimate of energy release by EQ
107
Transform boundaries often in the ocean and exception is the:
San Andreas; Shear stress can cause considerable accumulation of strain, and more strain= bigger EQ
108
What type of plate always subducts?
Oceanic or Continental
Oceanic
109
What are intraplate EQs?
EQs that are occasionally strong and happen far from the boundaries of lithospheric plates
110
Which waves cause damage to human structures?
P-wave
S-Wave
Surface Wave
Surface waves-Lateral motion/up and down rolling motion
Ex: If land pushes left, a house will fall to the right
111
The abrupt decrease in velocity causes wave amplitude to increase, is called
Ground Amplification
112
The Energy of corresponding seismic waves steadily decreases as they travel away from a focus is called
Wave Attenuation
113
--Most dangerous EQs are ones with large magnitude and
Shallow focal depths
114
The frequency at which a building will naturall vibrate when ground shakes during an EQ
Natrual Vibration Frequency
115
Crawl Space collapse
Cripple wall failure
116
Soft-Story collapse
When open space is taller than the failure
117
What is pancaking?
When floors fall from their columns in tall buildings causing a domino effect
118
subduction zone EQs can develop
Tsunamis
119
When Sand-rich layers of sediment behave like fluid
Liquefaction
120
Rock falls and mudflows are examples of
Mass WAsting events
121
Large open cracks in the ground are called
Ground Fissures
122
What is an EQ precursor
Foreshocks, change in land elevation, water levels and dissolved gases in wells, unusual patterns of low-frequency radio waves
123
Sections of active fault where the strain hasnt been release for an extended period of time is called the
Seismic Gap
124
Magmas:
Peridotite-ultramafic (mantle)
- PAtially melt it and get Basalt/Gabbro Magma
- Partially melt Basalt for Andesite/Diorite (intermediate)
- Partially melt andesite and diorite for Rhyolite (feslic) and Granite
125
What occurs at divergent boundaries, subduction zones and hot spots?
Volcanism
126
Molten rock is called
Magma
127
What is found mainly along convergent boundaries?
Volcanoes
128
Basaltic Magma occurs from
partial melting of the upper mantle
Can find this type of magma: in divergent boundaries and hot spots under oceanic lithosphere
129
130
Partial melting of ocean lithosphere (basalt) produces intermediate magma called:
Andesitic Magma
131
What type of magma forms at hotspots under continental lithosphere?
Felsic (Rhyolitic) Magmas
132
Viscosity is the
Resistance to flow; it is affected by temperature
-When Si02 increases, ability of magma to resist flowing increases
Ex: water is thin = low viscosity
133
Basaltic magmas:
Volcanic style: Flowing (effusive)
Abundance: Most Abundant
Volcanic Landform: Shield volcanoes, cinder cones, basalt plateaus
Andesitic Magma:
Volcanic Style: Effusive and Explosive; Abundance= common, Landforms= Composite (stratovolcano), calderas, cinder cones, domes
RHYLOTIC MAGMA:
Volcanic style: Explosive, Abundance= Rare, Lanforms= Lava Dome or plug, and Pyroclastic Flows
134
A combo of solidified lava, and pulverized rock particles are called
Pyroclastic material
135
When lava flows and cools/solidifies into rock on the surface, it's called a
Lava flow
-Magma reaches the surface and begins to move across the land
136
When lava builds steep sided mountains, it's called a
Lava dome
137
Basaltic flows move 1/2 mile an hour on gentle slopes and 6 mph in steep terrain
Travel 30 miles away from vent and in HI, they travel as fast as 35 MPH
138
Rhyolitic lavas
Don't move fast or travel more than 10 miles away from the vent
139
What type of a volcano is composed primarily of pyroclastic material, smallest and more abundant cone shaped volcanic feature, and are often relatively short lived?
Cinder Cones
140
Composite Cones or Stratovolcanoes
Characteristic of Convergent margins, deposit alernating layers of lawa flows and pyrolcastic material, classic Steep sided cone profile
141
What is the eruptive style of a composite cone?
Explosive and violent
142
What forms when magma is erputed from magma chamber and collapses back in on itself?
Collapse Calderas
143
Plumes of hot partly molten material that rise from deep in the mantle are called
Hot Spots
144
What is rock and glass fragments \<2mm in diameter; extremely abrasive and dense, and can short circuit electrical equipment and shutdown power systems?
Volcanic Ash
145
When steep flanks of a volcano become unstable and underlying material can fail, it;s known as
Volcanic Landslide
-Triggered by heavy rains and EQs
146
What is a mix of ash and rock and water? Can reach speeds of 20-40 MPH, can be like a river of wet concrete and can happen without a volcanic eruption?
Volcanic mudflow
147
H20, co2, and so2 make up this % of volcanic gases
95%
148
Common name for loose, broken down rock fragments at earth surface
Dirt
149
Solid rock that is under the dirt
Bedrock
150
Soil is anything that can be removed without blasting
Engineer definition
151
Natural mixture of mineral and organic matter that is capable of supporting plant life
Soil scientist/geologist definition
152
weathered material that hasnt been transported
Regolith
153
Material that has been transported by wind, water, or ice
Sediment
154
Different soil layers that have developed due to continued weathering and downward transportation of material by infiltrating water
Soil Horizons
155
soils that form on original regolith that overlies solid rock
Residual soils
156
Which horizon is unweathered rock within a few meters from the surface? (unaltered parent rock material)
R-horizon
157
Which horizon is the uppermost organic rich zone (topsoil)
A horizon
158
Which horizon has the remaining mix of weathered material?
C-Horizon
159
Which horizon has enriched minerals like clay, iron, & Aluminum Oxide?
B-Horizon
160
Which horizon is known as the zone of accumulation?
B horizon
161
which horizone is known as the zone of leaching?
E-Horizon; where clay and other minerals have been flushed from upper soil zone by infiltrating water
162
Which horizon is the upper most soil area in low lying poorly drained areas with lush vegetation and exceptionally rich in organic matter?
O-Horizon
163
Soil color, texture, and \_\_\_\_\_\_\_\_are important in the soil profile
Structure
164
What soil is the best agricultural soil?
Loam- good drainage and fertility
165
The 1% of soil that develops from thick accumulations of organic material is known as the
Parent Material
166
Soil horizons develop rapidly in what climate?
Warm, humid climates
-A&C horizons take less than 100 years to form
a-b-c horizon sequence takes several hundred years
167
What color are horizons O & A
Rich dark brown
168
What can affect color of soil?
Drainage
169
E horizon is generally ______ in color
Light
170
Which horizon is highly variable in color and can be red or yellow/brown?
B horizon
171
Granular, blocky, prismatic, and platy are all kinds of _____ ?
Structure
172
soils that form on transported sediment
Transported soils
173
soils that have developed in place on the underlying bedrock
REsidual soils
174
In a dry climate soils are dominated by what kind of weathering?
Physical
175
In what climate are soils dominated by chemical weathering?
Wet climates
176
Climate, parent material, organisms, topography, and time are what kind of factors?
Soil forming factors
177
Fraction of sediment or rock that consists of void space
Porosity
178
Controlled by mineral composition and dipolar nature of water molecule
Draught resistance
179
When water molecules attract to each other its known as
Cohesive force
180
Water molecules attracted to other molecules on a solid surface is known as
Adhesive force
181
The ability of a fluid to flow through interconnected pore space is known as
permeability
182
The ability of a material to deform without breaking when force is applied is known as
Plasticity
183
plasticity increases with
Clay content
184
The ability to resist being deformed is known as
soil strength
185
How easy a soil will lose its strength when disturnbed is known as
Soil sensitivity
186
Ability of a material to compact and reduce its volume when places under a force or load is known as
compressability
187
Clay minerals capable of incorporating large numbers of water colecules within their structure are known as
Swelling/expanding clays
188
Compressability increases with
increasing clay content
189
The process whereby dissolved ions attach themselves to soil particles and are then removed in a selective manner by growing plants and by water moving through the soil zone is known as
Ion Exchange
190
The ability of a soil to supply elements necessary for plant growth is known as
Soil fertility
191
Critical Elements for plants like Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, and Sulfer are known as
Essential nutrients
192
Movement or transport of soil particles away from their place of origin is called
Soil erosion
193
a net loss of soil due to soil erosion exceeding rate of soil formation is called
Soil loss
194
Contour plowing, strip cropping, no-till farming, grassed waterways, terracing, stream buffers, silt fences, retention basins, and slope vegetation cover are all ways of:
Mitigating soil loss
195
Salinity of soil water increases to the point that plant growth is reduced is known as
Salinization
196
A Layer whose physical properties limit the ability of either roots or water to penetrate into the soil is known as
Hardpan
197
Subsurface horizon that remains frozen throughout most or all of the year
Permafrost
198
Weathering of feldspar-rich rocks in tropical environments leads formation of bauxite
Aluminum
199
Clay mineral that is produced from feldspar-rich rocks
Kaolinite
used in cermaics, cosmetics, glossy paper, paint, medicines
200
Used as a fuel, now used mainly in gardening and potting soil
Peat
201
detailed maps of soil types that have been completed for agricultural regions of the country
Soil surveys
202
Driving forces of the water cycle:
Solar energy and gravity
203
Evaportation, transpiration, precipitation, infiltration, overland flow, ground water flow, and stream runoff are:
Processes in the water cycle
204
Volume of water moving through a channel over a given time interval is known as
Stream discharge
usually measured in ft3/sec
referred to as runoff
205
Ground water that discharges into the surface environment is
Groundwater base flow
-Fairly continous
206
The upper portion of a drainage system is known as the
Headwaters
207
Lowest part of a water system that empties into an ocean, lake, etc.
Mouth
208
How individual drainage systems are separated from one another by a topographic line along crests in the landscape is known as
Drainage divide
209
Land area that collects water for an individual stream or river
Drainage basin (watershed)
210
Steepness of a channel is
Stream gradient
211
Lowest level to which a stream can erode
Base level
212
Process where water separated sediment grains based on their size, shape and density
Hydraulic sorting
213
Deposition on inner banks is helping to build a flat plain on the valley floor
Natural Floodplain
214
When sand falls out of suspension and gets deposits on the edge of the bank where velocity change occurs
Natural Levees
215
Poorly drained areas of the floodplain
Backswamps
216
When old floodplains are left high and dry while a river migrates
Stream terraces
217
Stream discharge is calculated as Velocity x Area
Discharge = Q
Q= A x V
Area= depth x width
Depth = 6, width = 10, velocity is 5 ft3/sec
6x10= 60; 60x5 = 300; Q= 300 ft3/sec
218
This occurs where stream gradient in stream is high
Downcutting Erosion
219
This is common in meandering streams (lower stream gradient)
Lateral Erosion
- Velocity is higher on outside of meander stream
- Develops a cutbank
- Overhanging material eroded
- Process leads to wide stream systems
220
Bed load is made of
Sand and gravel
221
Suspended loads are made up of
Silt and clay
222
Biggest particle a stream can carry is called
Competence
223
Total load in a stream
Capacity
224
Stream deposits are called
Alluvium
225
Height at which a river begins to overflow its banks
Flood Stage
226
statistical calculation representing the frequency at which a particular value of stream discharge can be expected to repeat itself
Recurrence Interval
RI= (N+1)/M
N= # of values in the record
M= rank of a particular discharge max
227
ability of land surface to absorb water
Infiltration capacity
228
Where a river in lower parts of a drainage basin leaves its channels, flowing out onto its floodplain and inundating large areas of the valley floor
Downstream Flood
229
Carrying excessive sediment off the landscape and into drainage basin
Sediment pollution
230
Nature of precipitation evens (intensity and duration), Ground conditions (infiltration capacity and moisture conditions), and vegetation cover are all
Natural factors that affect flooding
231
Upstream floods that are produced by a short, intense rain event over a small amount of time is
A Flash Flood
232
Dams, natural levees, flood walls and channelization are all:
Structural ways to deal with flooding
233
What temporarily stores runoff water and releases it slower to a stream
Retention ponds
234
