Exam 2 Flashcards
warm front
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
cold front
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
Cyclones
convergence and
uplift typically cause
condensation and precipitation
Anticyclones
subsidence
causes air to be warmed,
producing clear conditions
Midlatitude cyclone
midlatitude, subarctic, and subantarctic
zones. Range from weak disturbances to powerful storms
Tropical cyclone
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.
Tornado
small intense cyclone of enormously powerful winds
Tornado much smaller in size than other cyclones, related to
strong, localized convective activity
eye of a tropical cyclone
- 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
Weather
what we observe day to day
Climate
- the average weather of a region over time
- minimum of 30 years
climograph
graphical representation of basic climates: monthly average temperature and precipitation, at a certain location.
climate close to oceans
large variation in precipitation
small variation in temperature
climate in the middle of continents
large variations in temperature
small variations in precipitation
climate at higher elevations
temperature is cooler
precipitation follows the curve
Desertification
(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.”
Köppen Climate System
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
Köppen Climate System categories
Tropical Mesothermal Microthermal Polar Highlands Desert/Dry
soil
a body of sediment that has been affected by
weathering, translocation, addition of organic material, and other soil forming processes
sediment
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
White soil
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
Black soil
Dark soil colors normally indicate abundance of organic matter (humus).
Red soils
Red-brown soil is caused by iron oxides. Ancient soils are highly productive with proper treatment. Cedar Mountain, Virginia
Regolith
the layer of unconsolidated rocky material covering bedrock
order of soil size from largest to smallest
gravel
sand
silt
clay
best texture for aggriculture
clay
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
types of soil structures
- granular
- platy
- columnar
- blocky
Soil horizons
distinctive layers found in soils that differ in physical or chemical composition, organic content, or structure.
cool moist soil pH
acidic
- low base in ions
arid climates soil pH
alkaline
Translocation
(fine particles are transported downward by eluviation and accumulate in lower horizons by illuviation
Transformation
minerals from primary to secondary, decay of organics
soil horizon order (top to bottom)
O, A, E, B, C
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).
what geological time period we live in
cenozoic
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)
law of superposition
- fundamental geological law – older rocks/sediments are lower in a profile than younger rocks/sediments.
law of horizontality
- sedimentary layers that are deposited, tend to do so in a horizontal manner (relative to the
Earth’s surface)
stratigraphy
- the field that studies these sequences and applies relative dating to sedimentary layers
Relative time
a general order of events (younger to older)
Absolute time
when you assign an actual calendar age, or number of years to an event
(radiometric dating)
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
Oceanic crusts
- composed of basalt
- more dense
- 5 miles thick
Continental crusts
- composed of felsic granite
- less dense
- 20 miles thick
most abundant elements in the Earth’s crust
- Oxygen (47%)
- Silicon (28%)
- Aluminum (8%)
rocks
composed of minerals
- usually composed of two or more minerals. Many different minerals may be present
minerals
naturally occurring inorganic
substances with a crystalline structure
Classes of rocks
(1) Igneous (2) Sedimentary (3) Metamorphic
Rock cycle
the cyclical transformation of earth surface
materials between igneous, sedimentary, and metamorphic states.