The shaping of the earth´s relief.ppt

THE SHAPING OF THE EARTH'S RELIEF

Sonia ÁlvarezAdrián Flor

Gonzalo OrtegaNerea Pascual

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INDEX1. Granite Shaping2. Structural Shaping3. Fluvial Shaping4. Groundwater5. Karst Shaping6. Shaping from surface runoff and torrents7. Coastal shaping8. Glacial Shaping9. Periglacial Landforms10.Wind shaping

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GRANITE SHAPING• Tors• Balanced rocks• Granites boulders

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TORS / BALANCED ROCKS

Various blocks of granite on top of each other.

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GRANITE BOULDERS

Large, smooth, rounded granite rock shaped by erosion.

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STRUCTURAL SHAPING • Mesas • Buttes• Crests

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MESAS

Are form because of the erosion of sediments on sedimentary basins

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BUTTES

Are like mesas but shorter.

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CRESTS

When the erosion forms more narrow mesas, they are call crests.

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FLUVIAL SHAPING • Rivers

V-shaped valleys• Bed loads

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V-SHAPED VALLEYS

In the higher course, the erosive action of the river forms valleys and when they have a V shape, they are call V-shaped valleys

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BED LOADSIn the lower part of the river, it loses strength and the sediments it was carring go to the bottom of the river forming bed loads.

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LANDFORMS FROM FLUVIAL SHAPING

Upper course:

Rapids

WaterfallsMiddle course:

Gorges

Canyons

Ravines

River mouth:DeltaEstuary

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RAPIDS

At the beginning of a river, there are many rocks and the water has a lot of strength so rapids are form.

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WATERFALLS

At the beginning of the river the terrains is not so eroded so the river forms waterfalls to continue his path.

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GORGES, CANYONS and RAVINES

When a river goes through very resistant rocks, valleys are formed with high vertical walls called gorges, canyons and ravines.

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DELTA

There are two types of river mouths, one of them are deltas, that are a body of sediments at the river’s mouth as it enters the sea.

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ESTUARY

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GROUNDWATERGround water forms part of the water cycle and it comes from infiltration from rivers lakes or rain into the ground. It is found in the pores, fissures and cracks of rocks.

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AQUIFERS AND THEIR DYNAMIC

Aquifers are layers of rocks or sediments that circulate or contains groundwater. To be an aquifer it must be porosity and permeability.

-Porosity is the percentage of open rocks that can fill with water.

-Permeability is the capacity of rocks to circulate water inside.

-Water goes down because of gravity through the aeration zone.

-The surface that separate this two areas is called water table this marks the level water will reach in a well that perforates the aquifer.

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KARST SHAPINGKarst is a spectacular landscape formed by the action of surface water and groundwater.

When water comes in contact with soluble rocks such as salt and gypsum, a dissolution process begins, which is responsible for this shaping.

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SPELEOTHEMS (STALACTITES AND STALAGMITES)

As well as dissolving the rocks, the water also precipitates particles dissolved in it and formations are created called speleothems.

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LAPIES

Grooves are formed by water dissolution as it runs over the surface.

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SINKHOLES

A circular depression formed by dissolution or the sinking of an underground cavity.

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GULLIES AND BADLANDSThe ground has different-sized grooves called gullies and ravines which form a landscape called badlands

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SHAPING FROM TORRENTS

Torrents are sporadic bodies of water with a fixed course, where there is a big break in the slope between a mountainous area and a flat area.

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The coastal shaping is the form that the coast adops.

Coastal areas are dynamic and changing

The coastal shaping is formed by:

-Movements of the sea (waves,currents...)

-Differential erosion of types of rocks

-Sediments that produce the rivers

-Human action

-Sea level changes

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COASTAL SHAPING

COASTAL LANDFORMS

There are two types of coasts. The high coast in which erosion predominates and low coasts where deposits predominates.

Beaches are marine deposit landforms, and depending of the size of the sediments could be sandy beaches or pebble beaches

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TOMBOLOS/LAGOONS

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GLACIAL SHAPINGGlaciers have a great capacity for erosion and transportation. (they are capable of digging deep valleys and pulling huge rocks along)

-In erosion it don’t select the sediments it pulls

-The sediments are deposited in long strips called moraines.

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PERIGLACIAL LANDFORMSThese are located close to glacial areas in high mountain areas. The temperature oscillates repeatedly above and below the melting point of water. This acts as a type of physical weathering called gelifraction or congelifraction. It forms an area of fragments at the foot of rocky walls, called scree.

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WIND SHAPINGWinds act on all parts of the planet but two factors are needed for the action to be effective:

-Abundance of fine loose materials: Sand,limestone or clay

-Absence of vegetation and moisture that fixes materials to the ground

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Aeolian or desert landforms

The most well known forms of erosions are desert dunes.

Dunes are formed where the wind meets an obstacle and deposits part of it sediment load. Once the dune is formed it favours sedimentation.

Leeward Windward

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