Landform Developed 2

Landform Developed By-Coastal Processes, Glaciers, and Winds.Labiba Nusrat JahanLecturer,PME, SUST.

Landforms developed by Coastal ProcessesAbyssal Fans, also known as deep-sea fans, underwater deltas, and submarine fans, are underwater geological structures associated with large-scale sediment deposition and formed by turbidity currents.

A bay is a large body of water connected to an ocean or sea formed by an inlet() of land due to the surrounding land blocking some waves and often reducing winds.

A beach is a landform along the shoreline of an ocean, sea, lake or river. It usually consists of loose particles which are often composed of rock.

A coastline or seashore is the area where land meets the sea or ocean.

The continental shelf is the extended perimeter () of each continent and associated coastal plain.

An island is any piece of sub-continentalland that is surrounded by water.

A lagoon is a shallow () body of water separated from a larger body of water by barrier islands or reefs.---In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water(11m or less beneath low water).

A mid-ocean ridge () is a general term for an underwater mountain system that consists of various mountain ranges (chains), formed by plate tectonics.

Oceanic Basin OceanSeaHydrologically, an oceanic basin may be anywhere on Earth that is covered by seawater, but geologically ocean basins are large geologic basins that are below sea level. An ocean is a body of saline water that composes a large part of a planet's hydrosphere.A sea is a large body of saline water that may be connected with an ocean or may be a large saline lake that, lacks a natural outlet. Sometimes the terms sea and ocean are used synonymously

Glacial landforms are those created by the action of glaciers.

GlaciersDefinition : a perennial [] body of ice that moves over land/water and forms from the accumulation and compaction of snow Flow down-slope from their own weight and gravityFlows due to the processes of gravity, sublimation and pressure meltingSublimation directly from solid to gasPressure melting pressure forces water to open areas to refreeze

Glacial FlowHow do glaciers move? Glaciers must be thick enough so that they flow down slope. Flow is by basal slip or plastic flow. Basal slip -- ice moves over a thin layer of melt water. Plastic flow -- ice deforms internally and flows like plastic.

Types of GlaciersAlpine confined by surrounding bedrock; relatively small form at mountain tops and flow down valleysPiedmont Alpine glacier that reaches lowlands and spreads outs Tidewater piedmonts or valleys that reach sea waterContinental ice-sheet only unconfined, cover large areas, usually at polesRock surfaced by rock, fragments and unconsolidated material

Types of GlaciersAlpineMuddy River Glacier, Frederick Sound, Alaska (1948)

Types of GlaciersPiedmontBylot Island glacier

Types of GlaciersTidewaterOutlet glaciers, Royal Society Fiord, Nunavut Bay, Canada

Types of GlaciersIce sheets/CapsIce cap complex, Iceland

Types of GlaciersRockNorthwest Territories, Canada

Glacier BudgetDefinition : difference between annual gain and loss of snow and iceWhen accumulation exceeds ablation the net budget is positive and glacier grows

Glacial DepositionGlacial Drift material left or moved by glaciers; extremely poorly sortedTill material directly deposited from ice, unsorted, unstratified with erraticMoraines deposits at edges of glacier where ablation is greatestDrumlins reworked moraines, blunt up-glacier, pointed in direction of flowOutwash sediments deposited down-stream from glacier melt-watersEskers sinuous [having many curves turns] deposits of outwash beneath the ablation zone iceLoess fine wind-blown silts deposits formed from outwash sediments

Glacial DepositionGlacial Till

Glacial DepositionMoraines

Glacial DepositionDrumlins

Loess

esker

Aeolian landforms are features of the Earth's surface produced by either the erosive or constructive action of the wind.

Wind as a Transporting Agent

Wind as an Erosional Agent

Desert Pavement

Ventifacts

Wind as a Depositional Agent

a dune is a hill of sand built either by wind or water flow.

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