Exam 2 Flashcards
1
Q
warm front
A
When warm air invades colder air.
- ‘slides’ up the cool air (can’t displace it) and is represented by a series of cloud formations and often light rain. Can lead to temperature inversions and stagnant air at the surface (in the cold air area)
- less dense
- moves slower
2
Q
cold front
A
When cold air invades warmer air.
- marked by wind shift, adiabatic cooling, water
vapor condenses, lowering barometer (because of air uplift), and often violent weather (due to unstable air)
- more dense
- moves faster
- lowering barometer
3
Q
Cyclones
A
convergence and
uplift typically cause
condensation and precipitation
4
Q
Anticyclones
A
subsidence
causes air to be warmed,
producing clear conditions
5
Q
Midlatitude cyclone
A
midlatitude, subarctic, and subantarctic
zones. Range from weak disturbances to powerful storms
6
Q
Tropical cyclone
A
tropical and subtropical zones. Range from
mild disturbances to highly destructive hurricanes or typhoons
- not at the equator
- originate as an easterly wave or weak equatorial lows, and they involve warm moist air.
7
Q
Tornado
A
small intense cyclone of enormously powerful winds
Tornado much smaller in size than other cyclones, related to
strong, localized convective activity
8
Q
eye of a tropical cyclone
A
- protected from the winds due to high rotation. The Eye is calm and actually has descending air from high altitude
- The descending air warms adiabatically and causes re-evaporation = more energy
9
Q
Weather
A
what we observe day to day
10
Q
Climate
A
- the average weather of a region over time
- minimum of 30 years
11
Q
climograph
A
graphical representation of basic climates: monthly average temperature and precipitation, at a certain location.
12
Q
climate close to oceans
A
large variation in precipitation
small variation in temperature
13
Q
climate in the middle of continents
A
large variations in temperature
small variations in precipitation
14
Q
climate at higher elevations
A
temperature is cooler
precipitation follows the curve
15
Q
Desertification
A
(land degradation)
- reduced precipitation by decreasing atmospheric moisture and raising surface albedo, which reduces local convective circulation and rainfall
- “the process by which fertile land becomes desert, typically as a result of drought, deforestation, or inappropriate agriculture.”
16
Q
Köppen Climate System
A
System of letters to label climates Classification is based on:
• Mean annual values of temperature
• Mean annual values of precipitation
• Season of highest precipitation (high-Sun, low-Sun)
• Precipitation of the driest month
17
Q
Köppen Climate System categories
A
Tropical Mesothermal Microthermal Polar Highlands Desert/Dry
18
Q
soil
A
a body of sediment that has been affected by
weathering, translocation, addition of organic material, and other soil forming processes
19
Q
sediment
A
unconsolidated granular material that has been
eroded by the forces of nature and deposited in some location. This is the Parent Material of a soil
20
Q
White soil
A
Salts form a white surface deposit on a plateau in western Argentina. Salts in the soil are carried upward and accumulate as water
from infrequent rainstorms evaporates at the surface. Salt-tolerant plants form a spotty vegetation cover
21
Q
Black soil
A
Dark soil colors normally indicate abundance of organic matter (humus).
22
Q
Red soils
A
Red-brown soil is caused by iron oxides. Ancient soils are highly productive with proper treatment. Cedar Mountain, Virginia
23
Q
Regolith
A
the layer of unconsolidated rocky material covering bedrock
24
Q
order of soil size from largest to smallest
A
gravel
sand
silt
clay
25
best texture for aggriculture
clay
26
Soil structure
refers to the way in which soil grains are clumped together into larger masses, called peds. Particles are bound together by soil
colloids to create peds ranging from small grains to large blocks
27
types of soil structures
- granular
- platy
- columnar
- blocky
28
Soil horizons
distinctive layers found in soils that differ in physical or chemical composition, organic content, or structure.
29
cool moist soil pH
acidic
| - low base in ions
30
arid climates soil pH
alkaline
31
Translocation
(fine particles are transported downward by eluviation and accumulate in lower horizons by illuviation
32
Transformation
minerals from primary to secondary, decay of organics
33
soil horizon order (top to bottom)
O, A, E, B, C
34
Catastrophism
theories which proposed that the Earth’s surface features were created in only a few thousand years by a series of catastrophic events (generally relating to divine intervention).
35
what geological time period we live in
cenozoic
36
Uniformitarianism
- James Hutton
- allowed for the development of the geologic time scale
- Says the same physical processes active in the environment today have been operating
throughout geological time
- Uses the present landform characteristics to
interpret the past (past processes)
37
law of superposition
- fundamental geological law – older rocks/sediments are lower in a profile than younger rocks/sediments.
38
law of horizontality
- sedimentary layers that are deposited, tend to do so in a horizontal manner (relative to the
Earth’s surface)
39
stratigraphy
- the field that studies these sequences and applies relative dating to sedimentary layers
40
Relative time
a general order of events (younger to older)
41
Absolute time
when you assign an actual calendar age, or number of years to an event
(radiometric dating)
42
asthenosphere
a semi-rigid, or plastic, zone that contains pockets of increased heat from radioactive decay and is susceptible to slow convective
currents. Capable of ‘slow’ flow. This layer is responsible for the Plate Tectonics in the Uppermost Mantle region
43
Oceanic crusts
- composed of basalt
- more dense
- 5 miles thick
44
Continental crusts
- composed of felsic granite
- less dense
- 20 miles thick
45
most abundant elements in the Earth’s crust
* Oxygen (47%)
* Silicon (28%)
* Aluminum (8%)
46
rocks
composed of minerals
| - usually composed of two or more minerals. Many different minerals may be present
47
minerals
naturally occurring inorganic
| substances with a crystalline structure
48
Classes of rocks
(1) Igneous (2) Sedimentary (3) Metamorphic
49
Rock cycle
the cyclical transformation of earth surface
| materials between igneous, sedimentary, and metamorphic states.
50
Igneous rocks
form when molten rock cools,
| forming silicate mineral crystals.
51
Extrusive igneous rocks
cool rapidly on the land surface or ocean bottom and show small microscopic crystals
52
Intrusive igneous rock
cool slowly below the Earth’s surface and develop visible (large) mineral crystals
53
Felsic
minerals (feldspar/silica) are light colored and less dense.
54
Mafic
minerals (magnesium/iron) are dark colored and
| more dense.
55
Sedimentary rock
layers, or strata, of mineral particles found in other rocks that have been weathered or from newly formed organic matter. Most inorganic minerals in sedimentary rocks are from igneous rocks.
56
Clastic sedimentary rock
rock and/or mineral fragments
57
Chemically precipitated sedimentary rock
formed by chemical precipitation from sea
| water or salty inland lakes
58
Organic sedimentary rock
formed from organic materials, coal, peat
59
Metamorphic rocks
```
formed from preexisting rocks by intense heat
and pressure (often associated with orogeny [mountain building]), which alter rock structure and chemical composition.
```
60
Tectonic activity
the breaking and bending of the Earth’s crust
| under internal Earth forces. This tectonic activity usually occurs when great lithospheric plates come together
61
Passive continental margins
accumulate thick deposits of continental
| sediments (e.g., east coast of US)
62
Active continental margins
have oceanic trenches where oceanic crust is
| sliding beneath continental crust. (e.g., west coast of US)
63
midoceanic ridge
a central axial rift where crust is being pulled apart
64
Spreading boundary
(Divergent) – crust is being pulled apart (rifting).
65
Converging boundary
(Convergent) – one plate is subducted beneath another.
66
Transform boundary
two plates glide adjacent to each other (strike-slip)
67
anticlines
upfolds
| - n
68
synclines
downfolds
| - u
69
hogback (or razor back)
upsidedown ^ sticking out of the ground
70
Fault
a fracture created in the brittle rocks of the Earth’s crust (rock must move for it to be a fault otherwise it’s a fracture)
71
Normal faults
```
caused by extension (rifting) and produce
downdropped blocks (grabens) and upthrown locks (horsts)
```
72
Reverse fault
an overhanging scarp that slumps downward is formed
73
Overthrust fault
one rock mass slides up and over another.
74
Transform fault (transcurrent)
(strike/slip), where blocks slide past one another
75
Tsunamis
- or seismic sea waves, are caused by major earthquakes, usually centered on a subduction plate boundary
- The sudden movement of the seafloor, near the earthquake source, generates a train of water waves that travel over the ocean in circles.
- Volcanic explosions can also produce strong tsunamis
76
Liquefaction
a phenomenon in which the strength and
stiffness of a soil is reduced by earthquake
shaking or other rapid loading. Makes seemingly “solid” ground act like a liquid.
77
Ring of Fire
- frequent Volcanic activity along subduction boundaries
| - around the Pacific Rim
78
hotspots
generate volcanic activity
79
Main Types of Volcanoes
* Stratovolcanoes
* Shield volcanoes
* Cinder Cones
* Flood Basalts
80
Caldera
- larger depression often lakes form in them)
81
Magma chamber
where the magma is held
82
Magma
intrusive molten rock
83
Lava
extrusive molten rock
84
Main vent
the main tube the lava comes up out of
85
Stratovolcanoes
- tall, steep cones built of
layers of felsic lava and volcanic ash
- felsic eruptions are often explosive.
86
Shield volcanoes
- mafic lava (basalt)
- explosions are usually quiet, and the lava travels long distances to spread out in thin layers.
- broadly rounded domes with gentle slopes
87
infiltration
to pass into or through
88
Water table
- the boundary between saturated and unsaturated zones
| - It is highest under hilltops and divides, and it slopes to intersect the surface at lakes, marshes, and streams
89
artesian well
Since the elevation of the well that taps the aquifer is below that of the range of hills feeding the aquifer, pressure forces water to rise in the well
90
Subsidence
the sinking of the ground surface due to excessive groundwater withdrawal
91
Eutrophication
The process by which a body of water acquires a high concentration of nutrients, especially phosphates and nitrates. These typically promote excessive growth of algae. As the algae die and decompose, high levels of organic matter and the decomposing organisms deplete the water of available oxygen, causing the death of other organisms,
such as fish. Eutrophication is a natural, slow aging process for a water body, but human activity greatly speeds up the process.
92
Overland flow (sheet flow)
can eventually concentrate into drainages which are unique flow patterns that characterize rivers, streams, etc.
93
drainage basin, or watershed
- consists of a branched network of stream channels and adjacent slopes that feed the channels
- It is bounded by a drainage divide
- All water in a watershed ends up at the same place (typically a flowing river)
94
Floodplains
lowlying areas flanking a river. The area that
| becomes inundated during high water events
95
Terraces
- elevations where the river once flowed (abandoned floodplains). The higher terraces are older than the lower terraces
- can form through tectonic uplift or river downcutting (usually as a result of base-level adjustment). They can be paired or unpaired.
96
Exotic rivers
– rivers that cross the desert but derive their flow from regions having a water surplus (e.g., Colorado River, US)
97
Salinization
- and waterlogging are undesirable side effects of long-term irrigation
- Arid regions watered by exotic rivers are most affected
98
bedload
- that portion of the stream load moving close to the channel floor by rolling or sliding
- sand gravel, larger particles
99
dissolved load
- dissolved matter is transported invisibly in the form of chemical ions. all streams carry some dissolved ions created by mineral alteration
100
suspended load
- clay and silt are carried in susspension
| - they are held within the water by the upward elements of flow in turbulent eddies in the stream
101
different types of drainages
- perennial
- ephemeral
- intermittent
102
perennial
- a stream or river (channel) that has continuous flow in parts of its stream bed all year round during years of normal rainfall
103
ephemeral
mostly dry, these channels flow for relatively brief periods during snowmelt or after rainfall
104
intermittent
have flowing water periods during the wet season (winter-spring) but are normally dry during hot summer months
105
drainage morphologies
- dendritic
- meandering
- braided
- anabranching
106
dendritic
- there are many contributing streams (analogous to the twigs of a tree), which are then joined together into the tributaries of the main river (the branches and the trunk of the tree, respectively).
107
meandering
- a straight river becomes windy
- forms when moving water in a stream erodes the outer banks and widens its valley, and the inner part of the river has less energy and deposits silt.
108
braided
- a channel that consists of a network of small channels separated by small and often temporary islands called braid bars
109
anabranching
- a section of a river or stream that diverts from the main channel or stem of the watercourse and rejoins the main stem downstream
110
gravitational water
- free water that moves through the soil due to the force of gravity.
111
hygroscopic water
forms very thin films around soil particles and is not available to the plant. The water is held so tightly by the soil that it can not be taken up by roots.
112
wilting point
the minimal point of soil moisture the plant requires not to wilt
113
epicenter
on earths surface
114
focus
in earth
115
worst earthquakes occur where
- plate boundaries
- subduction zones
- convergent
116
P waves
- primary waves
- first
- shake ground from side to side
- fast moving
117
S waves
- secondary waves
- slow moving
- second
- shaking up and down
118
New Madrid seismic zone
- far from any active plate boundary
| - one of the highest hazard areas for earth quakes in the nation
119
footwall
angled so you could climb up
120
hanging wall
would hang off of it. could not climb up
121
horst
a block pushed upward by the faulting
122
graben
a block that has dropped due to the faulting
123
flood basalt
the result of a giant volcanic eruption or series of eruptions that coats large stretches of land or the ocean floor with basalt lava.
