Landscapes – Upland Glaciation
Upland Glaciation
Ice Age
During the last Ice Age, 11 000 years ago, nearly all of Britain was covered by ice sheets. Only the far south of England
remained ice free. And that was only the most recent ice age - there have been several! So the landscape of the British
Isles that we know today has been carved by a series of huge ice sheets and glaciers. The evidence is all around - from
wide U-shaped valleys such as the Great Glen between Fort William and Inverness, the deep northern corries in the
Cairngorms, to jagged pyramidal peaks and aretes such as those found in the Cuillin Mountains on Skye.
Glacier
VIDEO LINK
A glacier is like a huge, deep and very slow moving river of ice. But how is a glacier
created? In winter snow builds up on mountain slopes and in summer, if it is not warm
enough, some snow will remain in shaded hollows. With successive snowfalls over the
following years, the snow builds up and the bottom layers have the air squeezed out of
them and turn to a substance known as névé or firn. Eventually this will turn into ice and
with further snowfalls, the ice will begin to flow downhill due to gravity. A glacier is born!
Watch this animation to
see how Glacial Erosion
can change the face of a
landscape over millions of
years: http://www.youtube.
com/watch?v=U7IC-L2fq2o
Glacial Erosion
Don’t Forget
Where the ice builds up in mountain hollows there are three different processes at work.
Firstly, as water which has found its way into cracks and crevices in the rock starts to
freeze, it expands by about 9% and helps to force the rock apart. When this happens
repeatedly, the rock eventually shatters. This is known as frost shattering (and also
freeze-thaw action). Secondly, as some of these fragments of rock are frozen into the
base of the moving ice, they scrape and grind away at the land over which the ice moves,
causing it to be eroded. This is called abrasion.
Remember to explain these
processes of glacial erosion
if you are describing the
formation of glacial features
such as corries, U-shaped
valleys, arêtes, etc.
Don’t Forget
Thirdly, as the ice moves it may freeze on to rock previously loosened by frost shattering
and pull it from the ground as it continues slowly downhill. This is called ice plucking.
Frost shattering, abrasion and ice plucking are the main ways in which ice erodes the
landscape to create the spectacular features associated with glaciation.
Corrie is a Scottish word.
Corries are known as cirques
in England and as cwms in
Wales.
1
Snow accumulates on
north-facing hollow
on mountain
3 Gap forms at back wall
of corrie (bergschrund)
Rocks frozen into glacier
base erode hillside
(abrasion)
Frost shattering and
abrasion deepen hollow
2 Snow continues to accumulate;
older snow turns to ice
and starts to flow
downhill forming
a glacier
4
Steep back wall of corrie
After the ice has melted a
bowl-shaped hollow is left.
This is a corrie. Often water
collects as a corrie lochan
or tarn.
Corries
A corrie is formed high on the slopes of mountains
where snow and ice have built up over many years.
Usually this is in shaded, often north-facing hollows. As
the snow and ice layers become deeper, the processes
of glacial erosion increasingly affect the rock at the base
of the hollow. Abrasion and plucking deepen the hollow
as the ice moves over it and frost shattering loosens
rock fragments which are incorporated into the moving
ice and lead to further abrasion. Slowly the hollow is
deepened into a bowl shape as the glacier grows and a
tongue of ice flows downhill.
When the ice has melted the bowl shape which has been
carved into the mountainside is known as a corrie. Often
there is a rock lip at the front of the corrie, where hard
resistant rock was scraped by fragments of ice in the
base of the glacier. These scratches are called striations.
The saucer shape at the base of the corrie often allows a
cont
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geography: sample pages
geography: sample pages
geography: sample pages
Landscapes
small lake or corrie lochan to form there. At the back of the corrie there are very steep
slopes or crags and cliffs where the ice eroded deeply into the land. Scree is found here
due to frost shattering which continues to break up the rock every time the temperature
falls below freezing point.
Aretes and Pyramidal Peaks
Online test
To test your knowledge
of Upland Glaciation, visit
http://cloud4test.com/hello/
tests
pyramidal peak
Several corries often form on the slopes of large mountains. As the
ridges of land between the corries are eaten into by the ice they
become narrower, while frost shattering acts to make the ridges more
jagged. After the ice melts a mountain may have a number of corries
separated by sharp rocky ridges. These are called aretes. Where three
or more aretes lead up to the mountain top, they can create a very
pointed summit, called a pyramidal peak. Scotland has many examples
of pyramidal peaks, such as Ben Lui.
arete
Ben Lui, Argyll: a pyramidal peak with aretes
Don’t Forget
U-Shaped Valleys
As glaciers flow downhill due to gravity they follow the course of old river valleys.
Glaciers flowing from many corries will join up to create a large valley glacier which is
immensely powerful. Contained within the glacier are millions of fragments of rock which
the ice has picked up on its journey. This leads to very powerful abrasion on the bottom
and sides of the valley whilst plucking also helps the ice to carve downwards, widening
and deepening it. If the temperature is warm enough the end of the glacier melts faster
than the ice is flowing and the snout of the glacier retreats back up the valley revealing
tributary
V-shaped
valley
small, tributary
glacier
main
glacier
hanging
valley
The Scottish Highlands,
with ranges such as the
Cairngorms, have some
excellent examples of
glaciated scenery. It is useful
to know at least one named
example of each landscape
feature you learn about.
U-shaped
valley
waterfall
1 Before the Ice Age:
River has eroded a V-shaped
valley. A tributary flows
down from the left.
2 During the Ice Age:
A glacier flows down the valley,
widening and deepening it due
to processes of glacial erosion.
misfit
stream
3 After the Ice Age:
A steep-sided U-shaped valley is left with a
wide flat bottom. The tributary now flows
from a hanging valley high up on the left.
the newly enlarged glacial U-shaped valley with very steep
sides and a wide flat bottom. Sometimes, where erosion has
over-deepened the valley, a long narrow lake called a ribbon
loch may form. Flowing along the floor of the U-shaped
valley the river is known as a misfit stream, whilst high on the
sides of the valley, steep crags or truncated spurs may have
formed, where the glacier has sliced off more gradual slopes
which existed before. Sometimes a smaller tributary glacier
which was less powerful than the main glacier and so didn’t
erode as deeply, causes a smaller U-shaped valley to be left
high up on the side of the main valley. This is called a hanging valley and the stream
flowing from it often descends into the main valley by means of a waterfall.
Strath Dionard, Sutherland:
a U-shaped valley
THINGS TO DO AND THINK ABOUT
1.Use Google Maps or look at a road atlas of Scotland
and find the mountainous areas above 750 metres.
Search for the named examples of glacial features
which have been mentioned on these pages.
2. In a world atlas, find these mountain ranges, which
are all examples of glaciated areas. The Lake District,
England; Snowdonia, Wales; The Alps, Switzerland; Rocky
Mountains, USA & Canada.
41
Urban Geography – DChanges in the Central Business District
Changes in the Central Business
District
Dynamic CBD
Don’t Forget
You should already know
the main land uses in
a typical CBD: offices,
shops, transport hubs,
entertainment venues,
restaurants, fast food
outlets.
The Central Business District is the most important part of a city. People travel to the
CBD for work, shopping and leisure activities. It is often also the oldest part of town and
buildings or whole areas sometimes need to be renewed to bring them up to date and to
meet the needs of the modern city. Also, as CBDs face increasing competition from out
of town shopping centres and business parks, city councils want to modernise the CBD
to keep it attractive for businesses, shoppers and visitors alike. City centres are dynamic
– they don’t stay the same for long as they are always changing.
Change in the CBD
Some of the most common changes found in the CBD are:
•
Pedestrianisation - shopping streets are made traffic
free in order to make them safer and more pleasant for
customers.
•
Public transport - has been improved to give people
an alternative to their cars (e.g. trams in Manchester,
Sheffield, Edinburgh).
•
Covered shopping centres - air conditioned, clean,
weather proof with easy access for families and
disabled. CBD have to compete with out of town
retail parks.
•
High rise office blocks - making the most of land which
is expensive due to shortage of space for development.
•
Multi-storey car parks - to get parked vehicles off of
the streets.
•
encouraging greater use of public transport by marking
Greenways (bus priority lanes) on the main roads into the CBD
•
opening a brand new bus station (in 2003) located beneath a new
upmarket shopping mall (Multrees Walk)
building multi-storey car parks (e.g. Greenside), to reduce on
street parking
cont
N
LOTHIA
N
ROAD
Castle
Grassmarket
Old buildings
refurbished and
upgraded to form
new wine bars,
coffee shops and
restaurants
REET
42
constructing a city ring road (bypass), completed in 1992
3 2
Traffic on Princes
Street restricted to
trams, buses and
taxis only
EET
Edinburgh tram
•
•
1
N STR
A major change in Edinburgh has been the developments aimed at
reducing the number of vehicles in the CBD (and also congestion,
air and noise pollution) by:
Although there are no skyscrapers, there have been many other modern
developments in the centre of Edinburgh. Land is expensive in any CBD,
especially in a major city such as Edinburgh, so developers will make the
most of any land they can get hold of. An old railway yard on the western
edge of the CBD which was used as a temporary car park has been developed into a new
financial district for the city along with a new 5-star hotel. On the south eastern edge of
the CBD, land which was once used by the brewing industry has been transformed by
two modern buildings - the Dynamic Earth Exhibition and the iconic building housing
the Scottish Parliament. These modern buildings stand side by side with some of the
oldest buildings in the city - the tenements at the foot of the High Street and Holyrood
Palace. Preserving historic buildings and protecting the view of them has presented city
planners with real difficulties. The Princes Mall underground shopping centre just north
of Waverley Station was built below street level so that the unique view of Edinburgh’s
historic skyline, including the Castle, was protected. More than most cities, Edinburgh
has imposed strong planning constraints on new city centre developments because of
the importance of tourism to the city economy - Edinburgh Castle, for example, is the
most visited tourist attraction in Scotland. Ensuring that the city’s historic views are not
diminished is good for business!
GE ST
GEOR
Transport
Old and New Together
Waverley Station
6
H
H H
7
ILE
Historic skyline above Waverley Station in Edinburgh’s CBD
adding new stations on the edge of the city (e.g. South Gyle &
Edinburgh Park) giving commuters new ways to travel to and from
the CBD
LM
ROYA
In 1995, the centre of Edinburgh was declared a United Nations
World Heritage Site in recognition of the unique character of
its buildings such as Edinburgh Castle, Holyrood Palace and the
Georgian New Town. This has been a major reason why there has
been little development of skyscrapers in Edinburgh - in order to
protect the unique views of Edinburgh’s historic buildings. However,
there has still been lots of change in its CBD.
•
QUEE
Edinburgh is a good example of a developed world city. As the capital city of Scotland,
home to 495 000 people, the second largest financial centre in the UK and home of
the world’s largest international arts festival, Edinburgh’s CBD is vitally important in
countless ways. Like most CBDs the centre of Edinburgh has experienced massive
change and continues to do so.
developing a new tram system to open in 2014 providing a fast route
into the CBD from the west
EET
S STR
PRINCE
s
Garden
Check out how much you
know about changes to CBDs
online at http://cloud4test.
com/hello/tests
Edinburgh City Centre: A Case study
•
s Street
Prince
Online test
geography: sample pages
geography: sample pages
geography: sample pages
Urban Geography
Holyrood Park
and Arthur’s
Seat
5
4
Holyrood Palace
H Old buildings converted to new
hotels (e.g. former Scotsman
newspaper office)
1 Edinburgh International Financial
Centre (former railway yard)
2 Edinburgh International Conference
Centre
3 Edinburgh Quay leisure and office
development
4 Site of Scottish Parliament (old
brewery)
5 Mew Scotsman newspaper offices
& Dynamic Earth exhibition
6 New shopping centre, new
department store, new bus station
7 Omni Centre: new leisure complex
& Greenside multi-storey car park
Sketch map showing selected changes in Edinburgh’s CBD.
Developments such as the new financial district at Clydesdale Plaza, the Dynamic Earth
and Scottish Parliament buildings at Holyrood, the Omni centre and multi-storey car
park at Greenside, and the new Edinburgh Quay leisure complex at the terminus of
the Union Canal are examples of how a CBD not only changes but grows outwards,
absorbing land that at one time was part of the inner city. So it is possible for the
location of the CBD to gradually change and grow with time.
Edinburgh Quay: A new
development on the edge of
Edinburgh’s CBD.
online
Check out this website about
Edinburgh’s business sectors
and explore the key areas of
Edinburgh’s CBD http://www.
edinburgh-inspiringcapital.
com/invest/key_business_
sectors.aspx
Don’t Forget
Edinburgh’s CBD is unusual
in that there are many
people who live there. Many
old commercial buildings
have been refurbished and
converted to flats and new
car free apartments have
been built (e.g. at Tollcross)
Don’t Forget
Tourism in Edinburgh is
hugely important to the
city’s economy, so all new
developments are either
directly for the benefit of
tourists such as new hotels
or are designed to blend in
with Edinburgh’s existing
architecture and the historic
skyline which tourists expect
to see.
THINGS TO DO AND THINK ABOUT
1. Study the information on these two pages, then close 2. Use the Ordnance Survey’s Getamap or Google Street
the book and try to write down six changes which have
View websites to study the CBD of Edinburgh and find
happened in Edinburgh’s CBD.
some of the sites described above.
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