GRADATION

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GRADATION par Mind Map: GRADATION

1. WATER

1.1. GLACIERS

1.1.1. continental

1.1.1.1. A broad ice sheet resting on a plain or plateau and spreading outward from a central névé, or region of accumulation. Continental glaciers are much larger than alpine glaciers but it can be more difficult to see how they have eroded the landscape. Sediments Larry are scraped away then the exposed bedrock is carved and polished by the passing ice. This happens much faster if there are lots of rocks and sand poking out from the bottom of the ice.

1.1.2. alpine

1.1.2.1. A glacier that moves down from a high valley. As the glacier grows, the ice slowly flows out of the cirque and into a valley. Several cirque glaciers can join together to form a single valley glacier. When valley glaciers flow out of the mountains, they spread out and join to form a piedmont glacier. Alpine glaciers pluck and grind up rocks creating distinctive U-shaped valleys and sharp mountain peaks and ridges.

1.1.3. abrasion

1.1.3.1. Sediment such as sand carried in the turbulent water can wear down rock surfaces along and below the water line. The sandpaper-like action scours rock surfaces and generally leaves them very smooth.

1.1.4. alluvial fan

1.1.4.1. fan-shaped deposits of water-transported material (alluvium) at the base of mountains. They are usually created as flowing water interacts with mountains, hills, or the steep walls of canyons. As a stream flows down a hill, it picks up sand and other particles—alluvium.

1.1.5. arête

1.1.5.1. a thin, almost knife-like, ridge of rock which is typically formed when two glaciers erode parallel U-shaped valleys. The arête is a thin ridge of rock that is left separating the two valleys. rêtes can also form when two glacial cirques erode headwards towards one another, although frequently this results in a saddle-shaped pass, called a col. The edge is then sharpened by freeze-thaw weathering, and the slope on either side of the arete steepened through mass wasting events and the erosion of exposed, unstable rock

1.1.6. attrition

1.1.6.1. A form of coastal or river erosion, when the bed load is eroded by itself and the bed. As rocks are transported downstream along a riverbed, the regular impacts between the grains themselves and between the grains and the bed cause them to be broken up into smaller fragments.

1.1.7. cirque

1.1.7.1. An amphitheatre-like valley head, formed at the head of a valley glacier by erosion. Cirques are created by glaciers, grinding an existing valley into a rounded shape with steep sides. The floor of the cirque ends up bowl shaped as it is the complex convergence zone of combining ice flows from multiple directions and their accompanying rock burdens, hence experiences somewhat greater erosion forces.

1.1.8. corrosion

1.1.8.1. The process in which some materials are dissolved by sea water.

1.1.9. tombolo

1.1.9.1. When a sand pit will grow long enough that it joins an island to the mainland.

1.1.10. crag

1.1.10.1. A rocky hill or mountain, generally isolated from other high ground. Crags are formed when a glacier or ice sheet passes over an area that contains a particularly resistant rock formation (often a granite, volcanic plug or some other volcanic structure). The force of the glacier erodes the surrounding softer material, leaving the rocky block protruding from the surrounding terrain.

1.1.11. tail

1.1.11.1. Frequently the crag serves as a partial shelter to softer material in the wake of the glacier, which remains as a gradual fan or ridge forming a tapered ramp (called the tail) up the leeward side of the crag.

1.1.12. drumlin

1.1.12.1. An elongated hill in the shape of an inverted spoon or half-buried egg formed by glacial ice acting on underlying unconsolidated till or ground moraine.

1.1.13. esker

1.1.13.1. A long, winding ridge of stratified sand and gravel. Most eskers are argued to have formed within ice-walled tunnels by streams which flowed within and under glaciers. Eskers may also form above glaciers by accumulation of sediment in supraglacial channels, in crevasses, in linear zones between stagnant blocks, or in narrow embayments at glacier margins. Eskers form near the terminal zone of glaciers, where the ice is not moving as fast and is relatively thin

1.1.14. hanging valley

1.1.14.1. A valley carved out by a small tributary glacier that joins with a valley carved out by a much larger glacier. The degree to which glaciers can erode down into the landscape is dictated by their size: the larger the glacier, the deeper the valley it can erode. A hanging valley is a shallow valley carved by a small glacier and thus the elevation of the valley floor is "hanging" high above the elevation of the valley floor carved out by the larger glacier (the main valley).

1.1.15. kettle lake

1.1.15.1. A shallow, sediment-filled body of water formed by retreating glaciers or draining floodwaters. Kettles are fluvioglacial landforms occurring as the result of blocks of ice calving from the front of a receding glacier and becoming partially to wholly buried by glacial outwash.

1.1.15.1.1. glacier outwash

1.1.16. plucking

1.1.16.1. A glacial phenomenon that is responsible for the erosion and transportation of bedrock especially large joint blocks. As a glacier moves down a valley, friction causes the basal ice of the glacier to melt and infiltrate joints in the bedrock. The freezing and thawing action of the ice causes cracks in the bedrock through hydraulic wedging. Eventually these joint blocks come loose and become trapped in the glacier.

1.1.17. lateral erosion

1.1.17.1. This process makes a river wider. This occurs mostly in the middle and lower stages of a river.

1.1.18. roche moutonnée

1.1.18.1. A rock formation created by the passing of a glacier. The passage of glacier ice over underlying bedrock often results in asymmetric erosional forms as a result of abrasion on the "stoss" (upstream) side of the rock and plucking on the "lee" (downstream) side.

1.1.19. tarn

1.1.19.1. a mountain lake or pool, formed in a cirque excavated by a glacier. It is formed when either rain or river water fills the cirque. A moraine may form a natural dam below a tarn.

1.2. COASTAL

1.2.1. abrasion

1.2.1.1. Sediment such as sand carried in the turbulent water can wear down rock surfaces along and below the water line. The sandpaper-like action scours rock surfaces and generally leaves them very smooth.

1.2.2. attrition

1.2.2.1. A form of coastal or river erosion, when the bed load is eroded by itself and the bed. As rocks are transported downstream along a riverbed, the regular impacts between the grains themselves and between the grains and the bed cause them to be broken up into smaller fragments.

1.2.3. corrosion

1.2.3.1. The process in which some materials are dissolved by sea water.

1.2.4. tombolo

1.2.4.1. When a sand pit will grow long enough that it joins an island to the mainland.

1.2.5. headland

1.2.5.1. A coastal landform. It is a point of land usually high and often with a sheer drop, that extends out into a body of water. They are formed when the sea attacks a section of coast with alternating bands of hard and soft rock. The bands of soft rock (eg. sand, clay) erode more quickly than those of more resistant rock (eg. chalk).

1.2.6. longshore drift

1.2.6.1. Waves usually approach shorelines on an angle; thus, the sand driven up the by the swash is transported along the beach horizontally. This is the zizag movement of sand along the beach in this particular way.

1.2.7. CONSTRUCTIVE

1.2.7.1. Build beaches adding sand to it. They occur on beaches with gentle slopes.

1.2.7.1.1. swash

1.2.8. DESTRUCTIVE

1.2.8.1. Destroys beaches by dragging sand back into the ocean. Occurs on steep slopes.

1.2.8.1.1. backwash

1.2.9. stack

1.2.9.1. A landform consisting of a steep and often vertical column or columns of rock in a body of water near a coast. They are formed over time by erosion processes

1.2.10. estuary

1.2.10.1. a body of water near the ocean that will rise and fall with the tides.

1.2.11. headward erosion

1.2.11.1. This makes a river longer. This erosion happens near its source. Surface run-off and and throughflow causes erosion at the point where the water enters the valley head.

1.2.12. stump

1.2.12.1. Formed by continuing wave action attacking a stack until it collapses

1.2.13. rias

1.2.13.1. Long, flooded river valleys that have been created by land subsiding or sea levels rising

1.2.14. fjord

1.2.14.1. Deep U-shaped glacial troughs created when a glacier eroded a river valley to the ocean.

1.3. GROUNDWATER

1.3.1. aquifer

1.3.1.1. A body of saturated rock through which water can easily seep through. Aquifers must be both permeable and porous.

1.3.2. artesian well

1.3.2.1. A confined aquifer containing groundwater under positive pressure. This causes the water level in a well to rise to a point where hydrostatic equilibrium has been reached. A well drilled into such an aquifer is called an artesian well if water reaches the ground surface under the natural pressure of the aquifer, in which case the well is called a flowing artesian well.

1.3.3. Karst

1.3.3.1. a distinctive topography in which the landscape is largely shaped by the dissolving action of water on carbonate bedrock (usually limestone, dolomite, or marble). It is characterized by underground drainage systems with sinkholes and caves

1.3.4. sink hole

1.3.4.1. a depression or hole in the ground caused by some form of collapse of the surface layer. Some are caused by karst processes—for example, the chemical dissolution of carbonate rocks or suffosion processes. They may be formed gradually or suddenly.

1.3.5. stalactite

1.3.5.1. A type of formation that hangs from the ceiling of caves, hot springs, or manmade structures such as bridges and mines. Forms when water flows through the Earth and into a cave. This water carriers a dissolved mineral called calcite and it is carried through cracks in the cieling.

1.3.6. stalagmite

1.3.6.1. A type of rock formation that rises from the floor of a cave due to the accumulation of material deposited on the cave floor from ceiling drippings.

1.4. RIVERS

1.4.1. alluvial fan

1.4.1.1. Alluvial fans are fan-shaped deposits of water-transported material (alluvium) at the base of mountains. They are usually created as flowing water interacts with mountains, hills, or the steep walls of canyons. As a stream flows down a hill, it picks up sand and other particles—alluvium.

1.4.2. attrition

1.4.2.1. A form of coastal or river erosion, when the bed load is eroded by itself and the bed. As rocks are transported downstream along a riverbed, the regular impacts between the grains themselves and between the grains and the bed cause them to be broken up into smaller fragments.

1.4.3. abrasion

1.4.3.1. Sediment such as sand carried in the turbulent water can wear down rock surfaces along and below the water line. The sandpaper-like action scours rock surfaces and generally leaves them very smooth.

1.4.4. corrosion

1.4.4.1. The process in which some materials are dissolved by sea water.

1.4.5. deltas

1.4.5.1. A landform that forms at the mouth of a river, where the river flows into an ocean, sea, estuary, lake, or reservoir. Deltas form from deposition of sediment carried by a river as the flow leaves its mouth. Over long periods, this deposition builds the characteristic geographic pattern of a river delta.

1.4.6. tributary

1.4.6.1. A stream or river that flows into a main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river serves to drain the surrounding drainage basin of its surface water and groundwater leading the water out into an ocean.

1.4.7. falls

1.4.7.1. A steep descent of the water of a river.

1.4.8. AGE

1.4.8.1. youth

1.4.8.1.1. 1. Steep slope. 2. Fastest river speed. The steeper the river, the faster the river. 3. Direction of erosion is vertical, headward. 4. Slope of valley walls is a narrow V-shape. 5. Few number of tributaries. Stream channels are just starting to be created.

1.4.8.2. mature

1.4.8.2.1. 1. Moderate slope. 2, Moderate river speed. 3. Direction of erosion is vertical, lateral. 4. Slope of valley walls is Open V-shape. Flood plain begins to formed. 5. A lot of tributaries. Stream channels are now well developed and effectively drain the interfluves.

1.4.8.3. old

1.4.8.3.1. 1. Small slope. 2. Slowest river speed. The flatter the slope, the slower the speed. 3. Direction of erosion is Lateral only. Deposition may occur. 4. Slope of valley walls is categorized as a wide valley floor. Peneplain stage where interfluve (a region between the valleys of adjacent watercourses) has been vertically eroded to meet the widening flood plain. 5. Few tributaries. The tributaries have fed the main river which now slowly meanders through the flood plain.

1.4.9. flood plain

1.4.9.1. An area of land adjacent to a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge.

1.4.10. levees

1.4.10.1. An elongated naturally occurring ridge or artificially constructed fill or wall, which regulates water levels.

1.4.11. meanders

1.4.11.1. A bend in a sinuous watercourse or river.

1.4.12. oxbow lake

1.4.12.1. a U-shaped body of water that forms when a wide meander from the main stem of a river is cut off, creating a free-standing body of water.

1.4.13. solution

1.4.13.1. Minerals are dissolved by river water and carried away in this manner.

1.4.14. split

1.4.14.1. A deposition landform found off coasts. At one end, spits connect to a head, and extend into the nose. A spit is a type of bar.

1.4.15. vertical erosion

1.4.15.1. This type makes a river channel deeper. This happens more in the upper stages of a river.

1.4.16. lateral erosion

1.4.16.1. This process makes a river wider. This occurs mostly in the middle and lower stages of a river.

2. MASS WASTING

2.1. TYPES

2.1.1. avalanche

2.1.1.1. mass of snow and ice that breaks away and slides down a mountain slope.

2.1.2. soil creep

2.1.2.1. It is the extremely slow and gradual movement of soil down a slope.

2.1.3. landslide

2.1.3.1. Extremely fast and dangerous downward movement of rock/soil. The fallen rocks at the bottom of the rock fall are known as scree or talus. In addition the resulting figure is called a scree slope, an unstable slope of angular rock.

2.1.4. slump

2.1.4.1. A section or slab of land that breaks away and slips a short distance downslope. In a slump, the top layer of soil and vegetation often remains completely intact. Slopes with considerable clay content usually slide or slump.

2.1.5. mudflow

2.1.5.1. A process where soil absorbs so much water that it all simply flows down. Sandy soilds can absorb water readily and tend to flow.

2.2. HUMAN CAUSES

2.2.1. logging

2.2.2. urban development

2.2.3. road construction

2.3. thermal expansion

2.3.1. Expansions and contradictions of rock causes splitting-off fragments; this process usually occurs in desert regions.

2.4. scree

2.4.1. A collection of broken rock fragments at the base of crags, mountain cliffs, volcanoes or valley shoulders that has accumulated through periodic rockfall from adjacent cliff faces.

2.5. oxidation

2.5.1. Occurs when oxygen combines with other elements in rocks to form new types of rock. These new substances are softer; thus, it is easier for other forces to erode these new substances.

2.6. hydrolysis

2.6.1. Occurs when rocks are decomposed by chemical reactions involving water; thus, allowing other forces to more easily break them apart.

2.7. hydraulic action

2.7.1. a form of erosion that occurs when the motion of water against a rock surface produces physical weathering. It is the process by which the force of water currents collide with the banks or bed of a river; thus, breaking and transporting the rock particles. Within this form of erosion, there are a number of more specific processes, including abrasion, attrition, corrasion, saltation, and traction.

2.8. exfoliation

2.8.1. The separation of successive thin shells from a massive rock. The thickness of these individual sheets can be from a few millimetres to a few metres.

2.9. abrasion

2.9.1. Sediment such as sand carried in the turbulent water can wear down rock surfaces along and below the water line. The sandpaper-like action scours rock surfaces and generally leaves them very smooth.

3. DESERT

3.1. plateau

3.1.1. An area of highland that is relatively flat.

3.1.1.1. mesa

3.1.1.1.1. Form when pieces of plateau seperate.

3.2. Hamada

3.2.1. When all the sand is removed from a desert leaving behind only the underlying rock.

3.3. playa

3.3.1. Flat-bottom depression found in interior desert basins, regularly covered by water that slowly filtrates into the ground water system or evaporates into the atmosphere, causing the deposition of particles along the bottom and around the edges of the depression.

3.4. canyon

3.4.1. Deep, steep-sided valleys called canyons formed during erosion by rivers.

3.5. DUNES

3.5.1. transverse

3.5.1.1. A continuous sand ridge. Forms in areas of abundant sand and in right angles to wind direction.

3.5.2. parabolic

3.5.2.1. Have horns that are usually anchored by vegetation and that point up wind. Forms around a blowout.

3.5.3. barchans

3.5.3.1. A migratory dune and has horns that point downward. They form over small obstruction.

3.5.4. seifs

3.5.4.1. Form in areas of little sand, where wind direction is continuous and form parallel to wind direction

3.6. loess

3.6.1. Wind-blown dust.

3.7. abrasion

3.7.1. Sediment such as sand carried in the turbulent water can wear down rock surfaces along and below the water line. The sandpaper-like action scours rock surfaces and generally leaves them very smooth.

3.8. tombolo

3.8.1. When a sand pit will grow long enough that it joins an island to the mainland.

3.9. alluvial fan

3.9.1. fan-shaped deposits of water-transported material (alluvium) at the base of mountains. They are usually created as flowing water interacts with mountains, hills, or the steep walls of canyons. As a stream flows down a hill, it picks up sand and other particles—alluvium.

3.10. attrition

3.10.1. A form of coastal or river erosion, when the bed load is eroded by itself and the bed. As rocks are transported downstream along a riverbed, the regular impacts between the grains themselves and between the grains and the bed cause them to be broken up into smaller fragments.

3.11. corrosion

3.11.1. The process in which some materials are dissolved by sea water.

4. WEATHERING

4.1. EROSION

4.1.1. BIOLOGICAL

4.1.1.1. human causes

4.1.1.1.1. agriculture

4.1.1.1.2. tourism

4.1.1.1.3. landscaping

4.1.1.1.4. urban development

4.1.1.2. scree

4.1.1.2.1. A collection of broken rock fragments at the base of crags, mountain cliffs, volcanoes or valley shoulders that has accumulated through periodic rockfall from adjacent cliff faces.

4.1.2. PHYSICAL

4.1.2.1. thermal expansion

4.1.2.1.1. Expansions and contradictions of rock causes splitting-off fragments; this process usually occurs in desert regions.

4.1.2.2. exfoliation

4.1.2.2.1. The separation of successive thin shells from a massive rock. The thickness of these individual sheets can be from a few millimetres to a few metres.

4.1.2.3. hydraulic action

4.1.2.3.1. a form of erosion that occurs when the motion of water against a rock surface produces physical weathering. It is the process by which the force of water currents collide with the banks or bed of a river; thus, breaking and transporting the rock particles. Within this form of erosion, there are a number of more specific processes, including abrasion, attrition, corrasion, saltation, and traction.

4.1.2.4. frost shatter

4.1.2.4.1. Form of physical weathering in colder climates where water penetrate the cracks in rocks. As the water freezes, it expands and the rock is weakened, causing it to fracture and break.

4.1.2.5. rain

4.1.2.5.1. Water droplets pound of weak material, breaking them up.

4.1.3. CHEMICAL

4.1.3.1. hydrolysis

4.1.3.1.1. Occurs when rocks are decomposed by chemical reactions involving water; thus, allowing other forces to more easily break them apart.

4.1.3.2. oxidation

4.1.3.2.1. Occurs when oxygen combines with other elements in rocks to form new types of rock. These new substances are softer; thus, it is easier for other forces to erode these new substances.

4.1.3.3. carbonation

4.1.3.3.1. Occurs when carbon dioxide reacts with certain types of rocks forming a solution that can easily be carried away by water.

4.1.3.4. scree

4.1.3.4.1. A collection of broken rock fragments at the base of crags, mountain cliffs, volcanoes or valley shoulders that has accumulated through periodic rockfall from adjacent cliff faces.

4.2. abrasion

4.2.1. Sediment such as sand carried in the turbulent water can wear down rock surfaces along and below the water line. The sandpaper-like action scours rock surfaces and generally leaves them very smooth.