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127 terms

Science Erosion, Weathering, Mass Movement

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Weathering
The process by which rock and other materials are broken down by the action of physical or chemical processes.
Mechanical Weathering
The breakdown of rock into smaller pieces by physical means.
Frost Action
The alternate freezing and thawing of soil and rock causes some mechanical weathering on rocks.
Ice Wedging
A type of Frost Action
Water seeps into cracks during warm weather. As temps drop, ice forms and expands, pushing against the crack in the rock and making it widen.
Abrasion
The grinding and wearing away of rock surfaces through the mechanical action of other rock or sand particles.
Wind Abrasion
When wind blows sand and silt against exposed rock, the sand eventually wears away the rock's surface.
Water Abrasion
As rocks and pebbles roll along the bottom of swiftly flowing rivers, they bump into and scrape against each other.
Gravity Abrasion
When rocks fall on one another, the force they exert on one another knocks pieces off.
Root Pry
Plants often send their roots into existing cracks in rocks. As the plant grows, the roots grow and can eventually put enough pressure on the rock that it can crack.
Chemical Weathering
The process by which rocks break down as a result of chemical reactions.
Acid Precipitation
Rain with high levels of acidity (from air pollution) can cause chemical reactions in a rocks minerals, breaking down the rock.
Acids in Groundwater
In some places, carbonic or sulfuric acids are found in the ground water and react with rocks like limestone creating caverns.
Acids from Living Organisms
Lichen and Moss produce an acidic waste products that break down rocks
Oxidation
a chemical reaction in which oxygen reacts with other elements to produce an oxide, like rust.
Differential Weathering
A process by which softer, less weather resistant rocks wear away and leave harder, more weather resistant rocks behind.
Surface Area
The amount of space on the suface of a rock. The more of this will make the rock weather faster
Soil
A loose mixture of small mineral fragments, organic material, water, and air that supports the growth of vegetations.
Parent Rock
The rock formation that is the source of the mineral fragments in a soil
Bedrock
The layer of rock beneath soil.
Residual soil
soils that remains above its parent rock. In this case, the parent rock is the bedrock.
Transported soil
is soil that has moved away from its parent rock due to water, wind, etc. The rock that is beneath the soil at its new location is the bedrock, but not the parent rock.
Soil Texture
The soil quality that is based on the proportions of soil particles
Soil Herizons
As soil forms, it develops separate soil layers
soil profile
is a cross section soil horizons
Mature Soil
Soil that has at least 3 layers and has taken 1000's of years to develop.
Immature Soil
Soil that 2 or less layers and has only been developing recently (less than 1000 yrs.)
Soil Fertility
The soils ability to hold nutrients and supply nutrients to a plant.
humus
which is the organic material formed in soil from the decayed remains of plants and animals
Tropical Rain Forest
Rich humus created by humid moist conditions, but heavy rains wash away soil, and soil left behind is sucked of nutrients quickly by density of plants needing nutrients.
Desert
Lack of rain means little chemical weathering, meaning soil is created at a slow rate. Lack of water means minerals can't dissolve and be sucked up by plants.
Temperate/Grassland
Enough rain so that minerals are dissolved to plant availability, but not so much that soil run's away.
Arctic
Basically a cold desert. Chemical weathering occurs slowly, soil formation occurs slowly. Humus forms slowly because decomposition of organic material is slow.
Soil Conservation
a method to maintain the fertility of the soil by protecting the soil from erosion and nutrient loss.
Desertification
occurs when plants can no longer grow in soil due to its condition. Land becomes a desert.
Erosion
the process by which wind, water, or gravity transport soil and sediment from one location to another.
Contour plowing
Prevents erosion during heavy rains
Terracing
Prevents erosion from heavy rains on steep hills
No Till Farming
Just enough tilling to plant seed.
Prevent erosion by proving cover that reduces water run off.
Crop Rotation
Rotate type of plant that uses land.
Prevents certain nutrients from being depleted.
Cover Crop
Grown a cheap crop that can decompose easily.
Restores nutrients to the soil
River System
A network of streams and rivers that drains an area of its runoff.
Tributary
A stream that flows into a lake or into a larger stream.
Watershed/Drainage Basin
The area of land drained by a water system.
Divide
Watersheds are separated from each other by an area of high ground
Channel
the path that a stream follows.
River
When streams become longer and wider
Gradient
The measure of the change in elevation over a certain distance.
Discharge
The amount of water that a stream or river carries in a given amount of time.
Load
The materials carried by a stream/river.
Bed Load
A stream can bounce large materials such as pebbles and boulders, along the stream bed.
Suspended Load
A stream can bounce large materials such as pebbles and boulders, along the stream bed.
Dissolved Load
A stream can bounce large materials such as pebbles and boulders, along the stream bed.
Young River
Its channels deeper than wide; fast flow; steep gradient; rapids and waterfalls; has few tributaries.
Mature River
Its channels are wider than deeper; slower flow; much smaller gradient; few falls or rapids; has many tributaries.
Young River
Its channels deeper than wide; fast flow; steep gradient; rapids and waterfalls; has few tributaries.
Old River
Low gradient; little erosive energy; River just deposits rock and soil along its channels; have wide flat floodplains along the banks.
Rejuvenated River
Found where land is raised up by tectonic activity; gradient becomes steeper and flows more quickly; Terraces can form.
Deposition
is the process in which material is laid down or deposited
Placer Deposits
Heavy minerals that are deposited at places in a river where the current slows down.
Delta
As a river's current slows when a river empties into a large body of water, the river often deposits its sediment creating a fan shaped pattern
Alluvial Fan
A delta, that forms on dry land.
Floodplains
The area along a river that forms from sediment being deposited when a river overflows its banks.
Flash flooding
As more land is being paved, more water is making its way into streams and rivers, which raises the natural level of these water sources. They often quickly flood covering road ways and destroying houses
Dam
A barrier that can redirect the flow of water.
Levee
A build up of the sides of a river by sediment, sand bags, or concrete walls.
Groundwater
Water located within the rocks and soil below Earth's surface.
Zone of Aeration (Upper Zone)
The zone that water passes through, near the surface, before it settles.
Zone of Saturation (Lower Zone)
-The area beneath the Zone of Aeration where the water collects, above the bedrock.
Water Table
-The boundary between the Zone of Aeration and Zone of Saturation
Aquifer
Rock layers that store groundwater and allow the flow of groundwater.
Good Porosity
A high percentage of open space between rock particles where water can hide.
Good Permeability
Allows water to pass through it easily.
The larger the rock particles are, the more permeable the rock is.
Rock that does not allow water to pass through it is impermeable
Recharge Zones
The ground surface where water enters an aquifer.
Artesian Formation
A sloping layer of permeable rock (aquifer) sandwiched between two layers of impermeable rock.
Cap Rock
The impermeable rock on top of the permeable rock (aquifer)
Artesian Spring
A spring whose water flows from a crack in the cap rock of an aquifer
If water gets heated by underground formations, the spring is a hot spring.
Wells
A human made hole that is drilled deeper than the level of the water table.
Cave
When underground water that contains weak acids (carbonic acid), and flow past a rock that easily weathers, a _____ will be created.
Dripstone Column
formed when a stalactite or stalagmite connect.
stalactite
roof in cave
stalagmite
floor in cave
Sinkholes
When a cave drys out, the roof of a cave can collapse leaving a circular depression in the ground
Point-Source Pollution
Pollution that comes from one specific site
Nonpoint-source pollution
Pollution that comes from many sources.
Primary Treatment
Water is passed through screens to catch solid objects
Water is put into a tank when small solids settle on the bottom
Secondary Treatment
Oxygen and bacteria is added to the water. Bacteria eat the waste materials.
Chlorine is added to disinfect the water, then it is released into a river, lake or ocean
60%, 32%, 8%
Houselod usage of Water:
Bathining, Laundry, Toilet:
Lawn, Pool, Car Washing:
Drinking, Cooking:
Shoreline
The place where land and a body of water meet.
Surf
name for breaking waves
Wave Period
time between breaking waves
Pounding Surf
The energy released when a wave breaks can cause a rock to crack or break apart, sending rock particles into the water or air and hitting other rocks.
Sea Cliffs
are formed when waves erode and undercut rock to produce steep slopes.
Sea Stacks
are offshore columns of weather resistant rock that were once connected to the mainland. Wave eroded the mainland leaving behind isolated columns of rock.
Sea Arches
form when wave action continues to erode a sea cave, cutting completely through the rock.
Sea Caves
form when waves cut large holes into fractured or weak rock along the base of sea cliffs (sed rock)
Headlands
are finger-shaped projections that form when cliffs made of hard rock erode more slowly than surrounding rock.
Wave-cut Terraces
form when a sea cliff is worn back producing a nearly level platform beneath the water at the base of the cliff
Beach
any area of the shoreline made up of material deposited by waves.
Longshore Current
A water current that moves sand in a zigzag pattern along the beach
Sandbar
An underwater or exposed ridge of sand, gravel or shell material
Barrier Island
A sandbar that has build up enough to have residents (Outer banks)
Barrier Spit
An exposed sandbar that is connected to the shoreline (Cape Cod)
Wind Erosion
An agent of erosion that removes soil, sand and other rock particles, and transports them from one place to another.
Saltaion
The skipping and bouncing movement of sand-sized particles in the direction the wind is blowing.
Deflation
The removal of fine sediment by wind.
Desert Pavement
fine particles are carried away, only soil left is pebbles and rocks.
Abrasion
The grinding and wearing down of rock surfaces by other rock or sand particles.
Wind Deposition
As wind slows down, it will begin to drop its load, just like water does when it is turning a bend.
Loess
Thick deposits of extremely fine grained sediment.
Dunes
When wind hits an obstacle, like a plant or a rock, the wind slows down and drops its sediment.
Glaciers
An enormous mass of moving ice
Alpine Glaciers
forms in mountainous areas: most common type
Valley Glaciers
glaciers from in the valleys created by stream erosion.
Continental Glaciers
Huge continuous masses of ice that spread across continents.
Till
Unsorted rock material that is deposited directly by the ice when it melts.
Stratified drift
A glacial deposit that is sorted into layers based on the size of the rock material.
Moraines
Most common type of glacial till
Lateral Moraines
form along each side of a glacier
Medial Moraines
form when valley glaciers with lateral moraines meet.
Terminal Moraines
form when sediment is dropped at the front of the glacier.
Mass movement
the movement of any material such as rock, soil, or snow, downslope.
Angle of Repose
The steepest angle, or slope, at which loose material will not slide downslope.
Land Slide
The sudden, rapid movement of a large amount of material down slope.
Rock Fall
Loose rock fall down a steep slope.
Not as massive a movement as a landslide
Mudflow
A rapid movement of a large mass of mud due to large amounts of rain or snow melt.
Lahar
mudflows of volcanic ash that occur if large amounts of rain fall after volcanic ash has settled after an eruption.
Creep
The extremely slow movement of material downslope.