Unit 5 Flashcards
the process by which rocks break down into smaller pieces by physical means
Mechanical weathering
cracking and breaking of rock through greeze-thaw cycles
Mechanical weathering: ice wedging
the grinding and wearing of rock surfaces through the mechanical action of other rock or sane particles
Mechanical Weathering: Abrasion
Mechanical Weathering: plant and animal activity
roots of plants or movement of animals cause breakdown of material
the process by which a metallic element combines with oxygen
Chemical weathering: oxidation
a chemical reaction between water and another substance to form two or more new substances
Chemical weathering: hydrolysis
the conversion of a compound into a carbonate
Chemical weathering: Carbonation
precipitation, such as rain, sleet, or snow, that contains a high concentration of acids, often because of the pollution of the atmosphere
Chemical weathering: Acid precipitation
Differential weathering: What affects the extent and rate at which rocks weather
Rock composition, Amount of Exposure, Climate, Topography, human activities, plants and animal activities. Affect the extent and rate at which rocks weather
Describe soil characteristics
- soil texture describes the size of the soil particals
a horizontal layer of soil that can be distinguished from the layers above and below it
Soil profiles: Horizons
dark, organic material formed in soil from the decayed remains of plants and animals
soil profiles: humus
soil profiles: Describe the different soil layers
Surface litter: fallen leaves and partially decomposed organic matter
Topsoil: organic matter, living organisms, and rock particles
Zone of leaching: dissolved or suspended materials moving downward
Subsoil: larger rock particles with organic matter, and inorganic compounds
Rock particles: rock that has undergone weathering
Bedrock: solid rock layer
What is the effect of climate on soil
it influences weathering processes which influence soil composition
Identify agents of erosion
wind, water, ice, or gravity
improper plowing of furrows, or long, narrow rows
Soil erosion: gullying
the process by which water flows over a layer of soil and removes the topsoil
soil erosion: sheet erosion
what are the results of soil erosion
Constant erosion of the A horizon leaves less fertile land.
Why is soil conservation important?
methods to prevent/reduce erosion rates; especially those caused by human activities
Identify farming methods that help conserve soil
Contour Plowing: fields are plowed in contours to follow that shape of land
Strip-cropping: crops are planted in alternating bands
Cover crops
Terracing: the construction of steplike ridges that follow contours of a sloped field
Crop Rotation: the process of farmers rotating the type of crops that are planted
dramatic and destructive mass movements
Mass movement: Rockfalls and landslides
saturation of soils can also contribute to movement of soil
Mass movement: Mudflows, slumps
the slow, down slope flow of soil saturated with water in areas surrounding glaciers at high elevations
mass movements: solifluction
the slow downhill movement of weathered rock material
mass movements: creep
rounds sharp peaks and valleys and eventually wear a mountain away
landforms: erosion of mountains
Landforms: Erosion of plains and plateaus
Plain: flat landform near sea level
Plateau: broad, flat landform that has a high elevation
Produce and shape plateaus and can wear down into mesas and buttes
Diagram the water cycle: Exapotranspiration
the total loss of water from an area, which equals the sum of the water lost by evaporation from the soil and other surfaces and the water lost via transpiration from organisms
Diagram the water cycle. condensation
the change of state from a gas to a liquid; produces clouds
Diagram the water cycle: precipitation
any form of water that falls to Earth’s surface from the clouds; including rain, snow, sleet, and hail
Earths water budget: Global vs. local budget
Factors that affect local water budget include temperature, vegetation, wind, and the amounts of rainfall.
Water use can also impact the water budget for a local area.
Avg. person in the US uses approx. 21,000 gallons of water a year.
Waste water used by cities and industry is often returned to rivers or oceans but wastewater may contain harmful materials.
While Earth holds a lot of water, only a small percentage of that water is fresh waster that can be used by humans.
To maintain freshwater we can look to conservation and alternative sources.
Earths Water budget: Importance of water budgeting
to maintain freshwater,
Earth’s Water Budget
Desalination
a process of removing salt from ocean water
Parts of a River System
Tributaries
a stream that flows into a lake or into a larger stream
Parts of a River System
Watershed
the area of land that is drained by a river system
what contributes to channel erosion
stream load: materials other than water carried by the stream, Stream discharge: the volume of water the flows within a given time,
Stream gradient: the change in elevation over a given distance; the steepness of the stream’s slope
Stream load: Suspended
Suspended load consists of particles of fine sand and silt that is suspended and carried in stream.
Stream load: Bed
load is made up of larger, coarser materials; moves by sliding and jumping along bed.
Stream load: Dissolved
the mineral components dissolved and transported in the stream
Types of streams
straight, meandering, and braided
one of the bends, twists, or curves in a low-gradient stream or river
Meander
a stream or river that is composed of multiple channels that divide and rejoin around sediment bars
Braided Stream
a fan-shaped mass of rock material deposited at the mouth of a stream
Forms when a stream deposits sediment into another body of water
Size determined by waves, tides, offshore depths, and sediment load
Delta
a fan-shaped mass of rock material deposited by a stream when the slope of the land decreases sharply
Forms when a stream deposits sediment on land.
Alluvial fan
an area along a river that forms sediments deposited when the river overflows its banks
Floodplain
raised banks of streams produced from the accumulation of deposits along the banks
Natural levees:
Impacts on flooding:
Removal of vegetation can inhibit soil integrity and water can move more freely
Logging and clearing of land can increase the volume and speed of runoff
Flood control:
Dams
Artificial levees: artificially created barriers that prevent the overflow of water ways
Floodways: permanent overflow channels can provide a way to carry away excess water
the water that is beneath Earth’s surface
Groundwater:
body of rock or sediment in which large amounts of water can flow and be stored
aquifer
he percentage of the total volume of a rock or sediment that consists of open spaces
Porosity
the ability of a rock or sediment to let fluids pass through its open spaces, or pores
Permeability
the zone that lies between the water table and Earth’s surface; most of the pore space if filled by air but water can move through
Zone of aeration
the layer of an aquifer in which the pore space is completely filled with water
Zone of saturation
Water table
the upper surface of underground water; the upper boundary of the zone of saturation
a hole that is dug to below the level of the water table and through which groundwater is brought to Earth’s surface.
Well
how does groundwater reach earths surface
through wells and springs
natural flow of groundwater to Earth’s surface in places where the ground surface dips below the water table.
spring
how do hot springs and geysers form
when groundwater is heated when its passes through rock that has been heated by magma.
water that contains relatively high concentrations of dissolved minerals, especially calcium, magnesium, and iron
Hard water
water that contains relatively low concentrations of dissolved minerals
Soft water
a natural cavity that forms in rock as a result of the dissolution of minerals; also a large cave that commonly contains many smaller, connecting chambers
Cavern
Sinkhole
a circular depression that forms when rock dissolves, when overlying sediment fills an existing cavity, or when the roof of an underground cavern or mine collapses
a type of irregular topography that is characterized by caverns, sinkholes, and underground drainage and that forms on limestone or other soluble rock
Karst topography
a large mass of moving ice
Glaciers
an almost motionless mass of permanent snow and ice; typically found at high elevations and in polar regions
Snow fields
Formation of glacial ice:
Begins with snow; summer snow loss is less than winter gain; snow is compacted and through recrystallization through melting and refreezing remove air
Firn: granular, compacted snow with air removed from crystals through compaction and refreezing
Glacial ice: largest degree of compression and recrystallization
a narrow, wedge-shaped mass of ice that forms in a mountainous region and that is confined to a small area by surrounding topography
Alpine glacier
a massive sheet of ice that may cover millions of square kilometers that may be thousands of meters thick, and that is not confined by surrounding topography
Continental glacier:
the process that causes the ice at the base of a glacier to melt and the glacier to slide
Basal slip
the process by which glaciers flow slowly as grains of ice deform under pressure and slide over each other
Internal Plastic Flow
in a glacier, a large crack or fissure that results from ice movement
Crevasse
parts of ice sheets that may move out over the ocean as a continental glacier moves outward/expands
Ice shelves
large blocks of ice that may break from the ice shelves and drift into the ocean.
Icebergs
a deep and steep bowl-like depression produced by glacial erosion
Cirque
a sharp, jagged ridge that forms between cirques
Arete
large rock transported from a distant source by a glacier
Erratics
rock material carried and deposited by glaciers
Glacial drift
unsorted rock material that is deposited directly by a melting glacier
Till
a landform that is made from unsorted sediments deposited by a glacier
Moraines
a deposit of stratified drift that lies in from of a terminal moraine and is crossed by many meltwater streams
Outwash plains
a bowl-shaped depression in a glacial drift deposit
Kettles
a long, winding ridge of gravel and coarse sand deposited by glacial meltwater streams
Esker
Milankovitch Theory
the theory that cyclical changes in Earth’s orbit and in the tilt of Earth’s axis occur over thousands of years and cause climatic changes
3 periodic changes that occur:
Eccentricity: changes in the orbital shape
Tilt: variations in the tilt of the Earth
Precession: a gradual change, wobble, in the orientation of Earth’s axis
a form of wind erosion in which fine, dry soil particles are blown away
Deflation
any rock that is pitted, grooved, or polished by wind abrasion
Ventifact
fine-grained sediments of quartz, feldspar, hornblende, mica, and clay deposited by the wind
Loess
flattened features created due to erosion or deposition of waves
Terraces
what creates longshore currents
Waves moving at a shallow angle to the shoreline
a water current that travels near and parallel to the shoreline
Longshore current
forms when sea level rises or when the land sinks
Submergent Coastlines
when the land rises or when sea level falls
Emergent Coastlines
a long ridge of sand or narrow island that lies parallel to the shore; formed when sea level rises over a flat coastal plain
Barrier Islands
