FEATURES OF GLACIAL EROSION

Slides:



Advertisements
Similar presentations
Corrie, cirque, cwm – hollow where a glacier formed
Advertisements

Formation of a Corrie.
Glaciation Learning Intentions
1. 4. Understand how. moving ice acts as an. agent of erosion and
The Grand Canyon. The Grand Canyon in Arizona was carved out of the Earth by erosion. Erosion is the process by which weathered rock and soil are moved.
Chapter 13: Glacial Processes, Patterns and Associated Landforms
Glacial Erosion This type of erosion is called abrasion. Ice
GLACIATION and RIVERS REVISION
Glaciation Revision for you. Get your revision techniques ready!!!! Here we go……………………
By the end of today's lessons you will be able to recognize Arêtes and explain the formation of glacial troughs and hanging valleys. Key Words; Glaciated.
Lithosphere: Glaciated Uplands 03/09/2010 Deposition 2.
Core Theme 2. The Natural Environment
Snow collects in hollows, especially on the less sunny north and east facing slopes, turns to glacial ice and moves downwards under the force of gravity.
Glaciation and O.S maps. Remember! Contour lines are very close together showing very steep land. The contour lines are curved showing a bowl- shape Sometimes.
LITHOSPHERE GLACIATION 1 Glaciation 2 Selkirk High School.
Glacial landscapes and landforms. Landscape means the overall look or feel of a place. The photograph shows an icy environment whose steep rugged mountains.
Glaciation revision.
Landforms Created by Glaciers
LITHOSPHERE - GLACIATION
I wonder how this valley was formed?
Cold Environments Distinct season below freezing with snow in winter. Can be defined by latitude and altitude ie.~ PolarArctic and subarctic PeriglacialSiberia.
Nature’s Bulldozers CGF3M Wed. Nov. 6, Glacial Erosion As glaciers move, they erode the land in two ways: plucking and abrasion. - Plucking occurs.
Glaciation 5th year Geography Ms Carr. Learning Intention Visualise what glaciation is. Name and briefly explain the formation of glacial landforms. Recognise.
LITHOSPHERE. In this unit we will look at… Glaciated Landscapes Limestone Landscapes Coastal Landscapes You will… 1.Learn about the landforms associated.
Glaciation Revision Session National 4/5 Geography.
 Physical landscapes - land use C2003  Look at Reference Diagram Q1E, Reference Diagram Q1A and the OS map. Give reasons for the pattern of land use.
Erosion and Deposition by Glaciers 1. What are Glaciers? Glaciers are: any large mass of ice that moves slowly over land 2.
How do Glaciers Effect the Land? By erosion & deposition.
Erosion and Deposition by Glaciers Chapter 4: Topic 8.
Geologic Features of Glaciation
Glaciers. Geologists define a glacier as any large mass of ice that moves slowly over land. There are two types of glaciers: Continental glaciers Valley.
LITHOSPHERE LANDSCAPE FEATURES RESULTING FROM GLACIAL AND FLUVIOGLACIAL ACTION Glacial Action by iceFluvioglacial Action by Meltwater Erosion Deposition.
Glaciated Landscapes Corrie Deep rounded hollows with a steep back wall. After the ice has melted a lake will be formed behind the rock lip, the lake is.
I wonder how this valley was formed?
Lithosphere: Glaciated Uplands 24/08/2010 Processes of erosion recap Corrie formation.
Glacier: Any large mass of ice that moves slowly over land.
Glaciation Revision for you. Get your revision techniques ready!!!! Here we go……………………
LITHOSPHERE GLACIATION 1 Materials carried by the glaciers are deposited in two main ways;  Glacial Deposits (unsorted) and  Fluvio-glacial deposits.
LITHOSPHERE GLACIATION 1 Introduction Higher Geography.
Standard Grade: Glaciation unit.
Glacial Features Geography 12.
Chapter 7.1b Glaciers.
Glaciation Revision for you.
Glaciation Revision for you.
Unscramble the words! Zefere Twah Sibarano Gnkpulic Enimroa Llubzngido Freeze thaw Abraision Plucking Moraine Bulldozing.
Landscapes: Glaciation unit.. Unit aims: To find out what we mean by glaciation. To find out how landscapes have been changed by glaciation. To be able.
LANDSCAPE FEATURES RESULTING FROM GLACIAL AND FLUVIOGLACIAL ACTION
They are all features of glacial erosion
Erosional Features 2 The Glacial Trough.
GLACIATION.
Glaciation Revision for you.
Understand how moving ice acts as an agent of erosion and deposition.
Standard Grade: Glaciation unit.
Unscramble the words! Zefere Twah Sibarano Gnkpulic Enimroa Llubzngido
GEOGRAPHY GCSE REVISION
Glacial Features on O.S. Maps
Extension: Describe this valley
Glaciated Landscapes.
1. 4. Understand how moving ice acts as an
LANDSCAPE FEATURES RESULTING FROM GLACIAL AND FLUVIOGLACIAL ACTION
Higher Glaciation - Erosional Features
Lesley Monk Balfron High School Session 2005/6
Lesley Monk Balfron High School Session 2005/6.
Starter: Look at the photos – what do they all have in common?
Llyn y Fan Fach Geography – Lesson 1.
What are Glaciers? Masses of ice formed on land by the compaction of snow.  Factor of glacier movement: gravity (caused by weight of ice)
Presentation transcript:

FEATURES OF GLACIAL EROSION Features of erosion These slide-shows are all on the Geography Blog, if you wish to copy any notes from them; we will not be stopping in class for you to do this FEATURES OF GLACIAL EROSION These are the features you will need to be able to describe, explain their formation, draw a labelled sketch of and recognise on an OS map. CORRIES PYRAMIDAL PEAKS ARETES U-SHAPED VALLEYS HANGING VALLEYS TRUNCATED SPURS RIBBON LAKE

A corrie is a deep, rounded hollow with a steep back wall. Features of erosion CORRIES Snow collects in hollows, especially on the less sunny north and east facing slopes, turns to glacial ice and moves downwards under the force of gravity Rocks are plucked out and the hollow is widened by abrasion to become a corrie. A corrie is a deep, rounded hollow with a steep back wall.

Also learn how to draw and label sketches. Features of erosion Read the in formation on the formation of corries in your notes and textbook page 91 There is a bullet-pointed list of actions explaining in order how a corrie is created. Learn this at home! Also learn how to draw and label sketches.

Features of erosion MAXIMISE YOUR MARKS ! NOTE;- the labels on the first two sketches are not just naming the features, like in sketch c). They describe what is happening in the sketch, naming the processes. This makes these labels -and the diagram- worth more marks than one where bits only are named!

Answer these questions in the usual way;- Features of erosion Answer these questions in the usual way;- Q1. Where is the bergshrund and what causes it? A. It is at the top of the back-wall, where the ice is ripping away from the rock because of gravity pulling the ice downhill. Q2.What erosion process greatly affects the backwall, and how does this affect the rock texture here? A.Plucking is the main process here and it leaves the rock jagged and rough.

Features of erosion Q3.The debris created by plucking is active elsewhere in the corrie- where and with what results? A.Abrasion uses the plucking products to smooth, deepen and enlarge the floor/ basin of the corrie. Q4. Describe how corries, aretes and pyramidal peaks are all related features. A. To create an arete, there has to be more than one corrie eroding the land between them into an arete. The eroded corrie back-walls eat into the summit of the mountain creating a pyramidal peak, where several aretes come together.

Features of erosion Formation of a corrie 12 Recap – this is the sort of diagram that you should be able to draw under exam conditions. Practice doing this.

Features of erosion Back wall scree lip Once the glacier retreats, the corrie may be filled with water. A small, generally circular loch is formed. This is known as a tarn or corrie lochan.

On an OS map, corries are shown as horseshoe-shaped features. Features of erosion On an OS map, corries are shown as horseshoe-shaped features. scree Note the east-facing aspect; snow lasts longer before melting. N Note the contours are very close together, especially on the steep backwall. Note also the bare rock symbol. tarn

Features of erosion Red Tarn

Features of erosion ARETE An arete is a narrow, sharp-edged ridge which forms the side walls of corries or separates different glacial valleys.

The red lines mark the spines of the three aretes. Features of erosion On a map an arete is hard to see. It is a long ridge between to corries or valleys. scree = arete The red lines mark the spines of the three aretes. horn bare rock These corries and arete are in the Cairngorms.

Striding Edge arete on Helvellyn, Lake District arete Features of erosion Striding Edge Striding Edge arete on Helvellyn, Lake District

Pyramidal peaks are also called horns. Features of erosion MATTERHORN Pyramidal peaks are also called horns.

Features of erosion A VALLEY GLACIER The next few slides will help to explain the formation of this feature.

Stages in the formation of a U-shaped valley Features of erosion 13 Stages in the formation of a U-shaped valley Take the handout and use page 284 of ‘Wider World’ to add the labels.

These are the actions that form this feature. Features of erosion These are the actions that form this feature. a) A glacier flows into an earlier 'V' shaped valley. b) The glacier abrades and plucks the sides and floor of the river valley. c) The valley is greatly deepened, widened and straightened. d) When the ice melts the valley is 'U' shaped. e) It now has very steep sides and a fairly flat floor. f) Any rivers are called 'misfit streams’ because they are far too small to have cut the valley.

Features of erosion Truncated spurs Former hill spurs are ‘truncated’- their ends are cut off by the ice action to form steep, sheer cliffs. The yellow lines show where the spurs were before they were chopped off! Note how they defined a V-shaped valley.

A U-shaped valley in Canada. Features of erosion A U-shaped valley in Canada.

Features of erosion When a glaciated valley is submerged or drowned by a rise in sea level, a fiord is formed. The sea lochs of western Scotland are the best examples of fiords in the British Isles. Fiord/fjord

Features of erosion A hanging valley Vertical erosion in the main glacier is far greater than in the tributary glaciers. So the valleys are not the same depth. After the glacier has retreated, rivers flowing down the tributary join the main valley via a waterfall Can you spot the river delta,too?

U-shaped valleys have few contours on their floors. Features of erosion Truncated spur U-shaped valleys have few contours on their floors. There is a hanging valley here. Note the very steep sides. waterfall Misfit stream

Features of erosion When a glacier moves along the valley, some parts are deepened more than others. When the glacier retreats, the deepest parts fill with water and become lakes. The English Lake District owes its character to these narrow ribbon lakes along its valley floors. Ribbon lakes

Material is dropped at the ‘break of slope’ to form this fan shape. Erosion/ deposition Caused when a stream falling from a side valley reaches flatter ground on the valley floor. Material is dropped at the ‘break of slope’ to form this fan shape. An alluvial fan (This is really a depositional feature.) alluvium = silt deposited by a river

These are partly erosional, partly depositional features. Erosion/ deposition A crag and tail Edinburgh Castle crag tail Plug of volcanic rock These are partly erosional, partly depositional features. The rock face facing the ice is steepened by glacial erosion. Softer rock on the other slope is protected from erosion to form a tail of boulder clay.

Features of erosion Identify the features marked on the diagram by matching them to the names of features listed below. Arête; Hanging Valley; Corrie; 'U' shaped Valley; Alluvial Fan; Pyramidal Peak; Corrie Tarn; Misfit Stream; Ribbon Lake; Truncated Spur; Screes.