Exam 3 Flashcards
(141 cards)
1
Q
How have humans altered earth’s surface?
A
-Vegetation cover and biodiversity
-Energy exchange with atmosphere
-Hydraulic processes
-distribution of materials
-greenhouse gas emissions
-air, soil, and water pollution
2
Q
Important GHGs
A
Carbon Dioxide, Methane, Nitrous Oxide
3
Q
Why are global biogeochemical cycles important
A
-regulate atmospheric composition
-influences climate on geologic and human time-scales
-sustain life on earth
-result of life on earth
4
Q
amount of different elements in reservoirs
A
stocks
5
Q
rate of flow among reservoirs
A
fluxes
6
Q
what are global biogeochemical cycles associated with
A
environmental pollution, ocean and soil acidification, eutrophication, global warming
7
Q
how else are humans affecting global biogeochemical cycles?
A
affecting soil fertility, agriculture, industry, human health, ecosystem health, biodiversity on land and oceans
8
Q
Biological carbon cycle pt1
A
Photosynthesis; CO2 into autotrophs
9
Q
Net Primary Productivity (NPP)
A
energy available for other organisms in of ecosystem; NPP=G(lobal)PP-R(esperation)
10
Q
Biological carbon cycle pt. 2
A
Respiration; Autotrophs return CO2 to the atmosphere
11
Q
consumer relation to biological carbon cycle
A
breath in air from plants, breath out CO2
12
Q
relation of dead organic matter to biological carbon cycle
A
some carbon is not respired, stays in soil and biomass (NEP)
13
Q
Net Ecosystem Production
A
long-term sequestration of carbon and energy (NEP=NPP-R (R=respiration of consumers and decomposers))
14
Q
what other aspect is carbon present in the atmosphere
A
Methane from production in the absence of oxygen
15
Q
when are chlorophyll levels highest in the Northern Hemisphere?
A
Spring, lowest in winter
16
Q
Human effects of the carbon cycle
A
-fossil fuel burning and industrial emissions
-changes in land cover and land use:
–Deforestation and converion grasslands
–Agriculture
–Drainage of peatlands
–fire
-Anthropogenic sources of methane:
–cattle
–waste management
–rice paddies
–biomass burning
17
Q
Three ex of direct human effects on the carbon cycle
A
1.) agriculture affects photosynthesis
2.)Fossil fuel combustion releases more CO2 in the atmosphere
3.) respiration and decomposition due to land use
18
Q
wo major sources of humans’ CO2 emissions
A
-fossil fuel burning (91%)
-land use change (9%)
19
Q
biological nitrogen cycle
A
N2 from the atmosphere fixates on an organism which then turns it into ammonium and/or ammonia (organic N) making it now usable by plants, the soil then nitrates the organic Nitrogen, sending it back to the atmosphere, where it can go around agin or oxidize into Nitrous oxide which is a GHG
20
Q
HUman effects on Nitrogen cycle
A
Haber-Bosch process
21
Q
Haber-Bosch process
A
creation of fertilizer: Nitrogen from the air + Hydrogen from natural gas+ Iron catalyst and high pressure= gasses are cooled and ammonia turns to liquid- unreacted gasses recycle nd meet with nitrogen and hydrogen, get catalyzed, repeats
22
Q
HUman effects of nitrogen cycle- increase of what N-fixing crop plants
A
soybeans, and clover- greater N2 fixation results in more Nitrogen susceptible to oxidation
23
Q
Human effects on nitrogen cycle pt3
A
Increase in industrial N emissions
-NOx Acid rain and smog
24
Q
Atmospheric N deposition yearly trend
A
increases in reactive nitrogen circulating through earth
25
where else can NO3- go?
down into the aquatic ecosystems
26
place with high Nitrogen yeild
mississippi bassin
27
What do high nitrates cause?
algal blooms
28
Human effects on nitrogen cycle
increased rates of N cycling overall
29
How has agriculture affected biogeochemical cycles?
-reduced C and nutrient storage in soil by crop harvest and tillage
-fertilization increases reactive N and phosphorus
-Irrigation increases CO2, N2O, and CH4
30
How has fire affected biogeochemical cycles?
-Fire as a primary land clearing agent globally
-Reduces C storage, increased C emissions from biomass burning and decomposition
31
How as pastures affected biogeochemical cycles?
-reduced C storage in plant biomass
-Increased CH4 emissions
32
trend of pastures
rapid expansion pastures worldwide
33
what does Dr. Asmeret Asefaw Berhe do?
her research works to understand how soil helps regulate the earth's climate
34
What are soils composed of?
solid(mineral and organic) and pre spaces(water and air)
35
How are soil properties determined?
chemical, physical and biological processes which are influenced by state factors
36
How are soils classified?
based on their properties into soil orders, many of which show strong geographic patterns
37
Five functions of soils
-recycling system for nutrients and organic wastes
-habitat for soil organisms
-Engineering medium
-systems for water supply and purification
-Medium for plant growth
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percent of 4 main components
45% solid (mineral), 25% water(pore), 25% air (pore), 5% Organic matter (solid)
39
How is particle size important
important for determining surface area and reactivity, which affects nutrient content, and porosity, which affects water holding capacity, oxygen diffusion, and drainage
40
Soil texture
measure of particle size distribution
41
5 Important functions of soil water component
Important solvent, chemical reactions with clay minerals, transports and leeches elements and nutrients, plant growth, soil microbial processes (eg decomposition)
42
Soil profiles
Soils have well-defined vertical profiles
soil formation is governed by processes of addition, loss, translocation, adn transformation
43
Addition processes
-Rock and parent material weathering inputs
-energy from the sun
-water inputs
-Oxygen and C from atmosphere
-Salts and elements through deposition
-N via N-fixation or N-deposition
-plant inputs
-sediments via deposition
44
Loss processes
-energy by radiation and conduction
-water by evaporation and transpiration or flowpaths
-N bt denitrification (N2 and N2O)
-CO2 by respiration and microbial decomposition
-CH4 by anaerobic decomposition
-soil by erosion
-nutrients by leaching
-nutrients by plant uptake and harvest
45
Translocation processes
-clay, organic matter and nutrients in soluble form by water or particulate form by gravity
-nutrient and water gradients driven by plant root uptake
-soluble salts carried in soil water
-soil mixture by animals or ice
46
transformation processes
-Plant, animal and microbial biomass decomposition
-physical and chemical weathering and changes in soil texture
-changes in soil structure(aggregation)
-biogeochemical reactions (chemical forms)
-Oxidation/Reduction reactions
47
State factors influencing soil development (CLORPT)
CL-climate, O-organisms, R-topography(relief), P-patent material, T-time
48
first pass field description of soils relies on what
color
49
what is distribution of soil orders determined by
CLORPT
50
Entisols
key CLORPT control: Time (young)
51
Inceptisols
Key CLORPT factor: Time (young-ish
52
Andisols
Key CLORPT factor: Parent Material (volcanoes)-high soil fertility, high water holding capacities
53
Gelisols
key CLORPT factor: Climate (cold-permafrost)
54
Aridisols
Key CLORPT factor: Climate (dry)
55
Histosols
Key CLORPT factor: Relief and climate (peaty soils, high organic matter, typical in wetlands)
56
Vertisols
Key CLORPT factor: Parent Material and CLimate (basaltic rocks, shrink-swell, structurally unstable)
57
Alfisols
Key CLORPT control: Vegetation and climate (high Al and Fe, broadleaf forests, typically sandy)
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Mollisols
Key CLORPT factor: Vegetation and Parent Material (typical grasslands, prairies, or on limestone bedrock) soft dark very fertile
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Most highly weathered soil orders
Spodosols, Ultisols, Oxisols
60
Spodosols
key CLORPT control: vegetation, climate, time- acidic forest soils, strongly leached surface layer, transformation of organic matter and metals to depth
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Ultisols
key CLORPT control: vegetation, climate, time- clayey soils, typical of humid tropics
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Oxisols
Key CLORPT controls: Vegetation, climate, time- low fertility, most nutrients lost to leaching
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most common soil orders in wisconsin
Alfisols and Spodosols
64
Geomorphology
process of shaping earth's landforms
65
Internal geomorphology
-energy from earth's heat
-plate tectonics
-folding, faulting
-volcanism
66
external geomorphology
-energy from the sun powers biology, weathering, and transport by wind and water (erosion)
67
earth's layers overview
composed of concentric layers, varying in phase and composition
68
how composition is defined
terms of elements, minerals, and rocks
68
three main rock types
igneous, sedimentary, and metamorphic- linked by the rock cycle
69
different properties of rock influence..
geologic processes at the very large scale and weathering rates at smaller scales
70
radius of earth
6,400 km (4000 mi)
71
how far down have we drilled into earth's crust
12 km
72
how do we know stuff about the center of the earth
seismic-wave travel
73
what happens to pressure and temperature as goes to earth's center
increases
74
volume of earths layers
solid inner core: ~4%
liquid outer core: 11%
Mantle: 84% (largest volume)
crust: 1%
75
Mantle charicterisitics
lower mantle: solid
upper mantle: 1.) Asthenosphere-hot, malleable silicate rock, source of magma
2.) upper mantle above Asthenosphere: relatively cool, solid silicate rock
76
what makes up the lithosphere
upper mantle, crust, and soils
77
thickness of earth's crust
uneven; ranges from 5-40 km thick- this is thin! eggshell
78
where is crust of earth thicker
under continents (ave 40 km) rather than oceans (ave 8km)
79
three categories of rock
igneous, sedimentary, metamorphic
80
property variation among rocks
-hard to sof
-fracture vs bend vs warp
-when heated: melt vs remain solid
-easily weathered vs not-easily weathered
81
silicate minerals
(SiO subx): most abundant
-Quartz (SiO sub2) (I)
-Feldspars
82
Non-silicate minerals
-carbonates (contain CO3) (I)
--Limestone
--dolomite
-Oxides (Metal+O) (I)
--Hematite
--Magnetite
-Sulfates
-sulfides
-halides
83
Key processes of rock cycle
-cooling of molten magma or lava
-weathering, erosion, and deposition
-Burial, compaction, and cementation
-tectonic uplift
-metamorphism (high temp and pressure)
-melting and rise of magma
84
Igneous rock classification
intrusive vs extrusive (crystal size)
85
Intrusive (plutonic) igneous rock
-cooled beneath the surface
-cooled slowly; large mineral crystals
- ex Granite
86
Extrusive (volcanic) igneous rock
-cooled above the surface
-cooled quickly; small mineral crystals
-ex Basalt
87
Igneous rock classification
Felsic vs Mafic (chemical composition)
88
Felsic igneous rock
-light colored rocks
-low density rocks
-common elements: high silicon and oxygen content
-common minerals: feldspar, quarts
- ex Granite, rhyolite
89
Mafic igneous rock
-dark-colored rocks
-higher density
-common elements: magnesium and iron (lower silicon content)
-common minerals: olivine
-ex. Basalt, gabbro
90
Igneous rock grain
plutonic/ intrusive=coarse-grained
volcanic/ extrusive=fine-grained
color is dependent of content of Si- high=felsic, low=mafic
91
continental crust
dominated by granite
Felsic: silicate rick
light colored
thicker, low density
92
oceanic crust
dominated by basalt
mafic: magnesium and iron ricj
dark colored
thinner, higher density
93
basalt flows
black sand beach
94
extrusive igneous rocks
obsidian, andesite, pumice
95
sediments
formed by weathering, transport, and deposition
96
weathering
breaking down of existing rocks into smaller fragments and more stable minerals
97
transportaiton
by wind, water, ice to areas of deposition
98
deposition
in areas of low energy, low elevation, eg ocean floor, lakes, river valleys
99
sedimentary rocks
formed by deposition of sediments, subsequent compaction and cementing: -classified by grain size, mineral composition, and formation
-layers=strata
100
two major kinds of sedimentary rock
-fragments of pre-existing rock eg sandstone
-precipitation of soluble compounds or by chemical reactions eg coal and limestone
101
sedimentary rocks
-sandstone ; mining for silica (quartz) sand for hydraulic fracturing (fracking)
-limestone
-shale
-source of fossil fuel
102
metamorphic rocks key information
-formed by transformations by heat and pressure
-two major kinds --contact metamorphism, where magma contacts other rocks (heat) --rocks deep within crust under large volume of overlying rocks (pressure)
-classified according to grain size and parent material: --slate: fine crystals --schist: visible crystals --gneiss:bands of easily visible quartz, feldspar and mica
103
Metamorphic rocks
gneiss, quartzite, slate outcrop (from shale), Marble quarry (from limestone)
104
distribution of main rock types in the US
most of earth's crust (96%) is composed of metamorphic and igneous rocks, most exposed rock (75%) is sedimentary
105
Wegener's continental drift theory (1915)
-one super continent: pangaea
-proposed: gradual displacement and drifting apart of continents ('continental drift')
now called 'plate tectonics'
106
evidence of continental drift
-the 'jigsaw' continents
-similarity of rock types and mountain belts across continents
-similar coal deposits and evidence of past glacial deposits across continents
-fossils
-geographic distributions and evolutionary histories of living species
107
key problems of continental drift theory
-at the time, earth was though to be mostly solid and rigid (except for magma)
-unknown source of energy that would pull the plates apart
-earth was not thought to be old enough to occur
108
evidence supporting "continental drift"
- seafloor spreading evidence: --ocean floor magnetic reversals --ocean floor age --mid-oceanic ridges and deep-sea trenches
-plate boundaries: --volcanoes --earthquakes
-mechanisms: subduction, "slab pull"
-new methods to date age of earth
109
mechanisms for plate tectonics
-Heat produced deep in mantle by energy released by radioactive decay, melts mantle rock
-Asthenosphere is source of magma that rises at seafloor spreading zones. Cooling plate become thicker and denser away from ridge
-Denser oceanic plate moves below continental plate at convergent boundary -> Subduction
-“Ridge push” and “Pull slab” model of plate tectonic movement
110
proof of seafloor spreading
-increasing age of seafloor away from ridges
-magnetic stripe reversals in ocean crust (magnetic minerals in cooling rocks orient Earth’s magnetic field and that field has flipped at different times in Earth’s history)
- ocean floors are not flat (not a basin for sediment)
*Marie Tharp and ig Bruce Heezen
111
plate boundaries and earthquakes
earthquake activity is concentrated along mid-ocean ridges and deep sea tranches
112
earths tectonic plates
7 major plates (94% of surface area)
~ 20 plates (major and minor)
113
Supercontinent to continents timeline
-pangaea: 250 million years ago
-start to break: 225 million years ago
-large differentiation begins: 135 million years ago
-even further movement: 65 million years ago
114
Plate boundary key facts
-high geologic activity and hazards at plate boundaries
- three types of boundaries: convergent, divergent, transform
115
three convergent plate boundries
oceanic-continental, oceanic-oceanic, continental-continental
116
oceanic-continental
subduction occurs
volcanoes
earthquakes
-Andes Mouitains
117
oceanic-ocieanic
subduction
volcanoes (volcanic islands)
earthquakes
-deep sea trenches along eurasian, pacific, and philippine plates
118
continental-continental
no subduction
earthquakes most common
mountain building
-Himalaya
119
Pacific ring of fire
75% of world's earthquakes and volcanoes
120
divergent plate boundaries
Mid-ocean ridges (oceanic-oceanic)- ie Iceland
rift valleys (continenta-conitnental)- East African Rift Vally
121
Convergent boundary: tectonic uplift
-Oceanic plate subducting beneath continental plate at collisional boundary
-Flat subduction pushes
compression farther inland
122
Transform Plate Boundaries
horizontal motion, primarily
-along pacific plate and north american plate in california: earthquakes
123
Diastrophism
deformation of the crust, rocks break or bend due to pressure from either tectonic movement or rise of molten magma
124
Diastrophism: folding
crus subject to lateral compression; can form parallel folds
-most is subterranean; get exposes through erosion
125
Diastrophism: Faulting
crust breaks apart due to stress, displacement along zones of weakness, associated with earthquakes
126
fold types
monocline, syncline, anticline, overturned, overthrust
-ex Appalachian mountains, ouachita mountains
127
Fault types
normal, transverse faults (strike-slip), Compressional: throust, compressional: reverse
128
Normal faults
Tensional fault; vertical movement,
tension stress pulls crust apart
* Produces steeply inclined fault zone, scarp with upthrown and downthrown blocks
* Ex. Sierra Nevada mountains in CA and Kenya Rift Valley
129
Horst and Grabens
horst=middle goes up, graben=middle goes down
-both formed by normal faults
-ex basin and range province, Nevada
130
Reverse fault
compressional fault; vertical displacement due to compression stresses
* Upthrown block rises above downthrown block
* Landslides are common
131
Thrust fault
compression drives upthrown over
downthrown block
* Frequently leads to mountain building
* Can overturn strata (layers; older over younger)
132
strike-slip faults
lateral displacement
* Visible on landscape when features are offset
* Ex. along transform boundaries (but not exclusively)
133
volcanic activity
o Irregular distribution but associated primarily with plate boundaries:
A) Divergent: magma wells up at spreading zone
B) Convergent: subduction
o Granite (felsic): high viscosity, thicker, more explosive (pyroclastic); ex., Mt. St. Helen’s
o Basalt (mafic): hotter and more fluid, typically nonexplosive; ex., volcanoes on Hawaii
134
lava flows
flattening effect on topography
135
peaks
shield volcanoes, composite volcanoes, Lava dome, cinder cone
136
shield volcano
largest, quiet eruptions of lava, broad, gently sloping cone
-crust moves over hotspot
-basalt- over hotspots- non-violent
137
composite volcano
large, steep-sided, asymmetrical; intermediate, lava flows and pyroclastic explosions (fragments of rock and lava)
ex Mt. St. Helen's- may of 1980
-large eruptions of ash and aerosols can penetrate stratosphere and cool climate
-Mix of high silica (more reactive) and low silica (less reactive)
138
Lava dome
masses of very viscous lava, lava bulges from vent and dome grows by expansion
139
Cinder cone
smallest, ash hills, cone-shaped or saddle-shaped peaks
-big pile of rubble that occured over a pot of magma
140
caldera
basins formed when volcano explodes or collapses (cauldron)
-ex crater lake
