Monday 15 December 2008

Sunday 4 May 2008

Coastal erosion processes

You need to be able to define the four main processes of coastal erosion.

Corrasion (abrasion) - this is where the bits of rock and sand carried in the waves grind down cliffs.

Attrition - this is where the waves cause rocks and pebbles that they are carrying to smash into each other and break down. They become smaller and rounder.

Solution - this is where acids contained in sea water slowly dissolve certain types of rock.

Hydraulic Action - this is the constant force of waves crashing on the shore. When waves crash against the cliffs they force air into cracks in the rock. The air is trapped, and pressure builds up. As the waves move back, pressure is released and the trapped air expands. Small explosions take place and weaken the rock.

You might find it useful to remember the 4 processes using the phrase CASH.

The BBC Bitesize website has a useful animation showing these four processes. Click here to visit this page.

Remember the Coastal Kung Fu from our lessons? This activity was designed by Portchy from SLN. Thanks! Click on the image to re-live the experience.

Saturday 3 May 2008

Constructive and Destructive Waves

Constructive waves are low energy waves with a stronger swash than backwash. Where there are less than 8 waves breking each minute they tend to be constructive waves.

Constructive waves tend to deposit material and build up a beach.


By contrast, destructive waves have much higher energy. They are much larger in height. They have a weak swash but a strong backwash, and they therefore erode the beach by pulling sand and shingle (beach materials) down the beach as water returns to the sea.


The Wycombe High School website has some excellent animations of both constructive and destructive waves. You can see them here. Alternatively, you could look at the Curriculum Bits website animations.

Waves

Waves get their energy from the wind. As the wind blows over the surface of the sea, it creates friction. This frictional drag causes water particles to rotate and their energy is transferred forward in the form of a wave. Whilst the water moves forward, the water particles return to their original position.

As a wave reaches shallow water, friction between the sea bed and the bottom of the wave causes it to slow down. Its shape becomes more eliptical (rather than circular). The top of the wave is not affected by the friction, and it becomes steeper until it eventually breaks.

When the wave breaks, water rushes up the beach. This is called the swash.

The movement of water back down the beach is called the backwash.

There are three main factors that affect the strength of a wave:

1. The strength and speed of the wind.
2. The duration of the wind - this is the length of time for which the wind has blown.
3. The fetch - this is the distance over which the wind has blown.

The Wave Machine Simulator helps you to see the impact of these three variables.

A model of the coast

As we work through this unit, try to keep this model of the coastal system at the front of your mind. Remember that the processes of erosion, transportation and deposition are closely linked. The lesson about coastal processes in Harlech should remind you of this!

Water, landforms and people: coasts

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The exam board has set the following key questions for this section of the course:

* What is meant by processes of erosion,transport and deposition at the coast?
* How do these processes contribute to the development of distinctive coastal landforms?
* What coastal landforms are produced?
* In what ways do these natural processes and the coastal landforms they produce affect human activity?
* In what ways does human activity affect the natural processes and coastal landforms?
* What conflicts arise from the management of coastal processes and landforms?
* How and why do these conflicts arise?
* How can conflicting interests be managed to minimise negative effects and maximise the positive effects of human activity on coastal processes and landforms?

Here is the topic overview sheet which you were given in the lesson.

Read this doc on Scribd: Coasts outline

Wednesday 2 April 2008

Climate Change - Taking Action

The official website for the Al Gore film 'An Inconvenient Truth' has a section which allows you to calculate your own personal carbon emissions and then suggests ways in which you can reduce them. Click on the image to visit the site.


Why not ask your family to commit to saving 20% of their energy? The Energy Saving Trust website has some great ideas about how you can do this and includes a carbon counter - click on the logo below to visit their 'Click to Commit' campaign website. You will be asked to dedicate your carbon savings to a place that is special to you. To do this, you will need to upload a photo of your chosen location. If you haven't got a photo to upload, you could have a look at those that have been put onto the Geograph website. Click the link below to visit this site.

Visit the Energy Saving Trust Commit website to make your commitment

The Geograph project aims to host a photo for each 100 metre grid square in the UK. It's an amazing resource of images. What could you add to it? To see my Geograph photos, click here.

Cambridge City Council has launched its own Climate Change Charter. The Leys School has signed up. Do you think we should too? If so, contact one of the EcoSchools team and let them know how you feel about this issue and why!


We are hoping to be able to get the City Council's Climate Change exhibition tour to visit us at Chesterton. Please contact Dr Hutchinson if you would be prepared to help out with organising this event.

Diesel adverts - what do you think?

Climate Change - how is it affecting people?

Climate Change is affecting people in lots of ways. Why not have a look at the Global Eye website for some mini-case-studies of the ways in which people's lives have been affected by climate change?
And for a light-hearted analysis of the ways in which our lives could change as a result of global warming, have a look at the advertising campaign 'Global Warming Ready' from Diesel. The campaign includes newspaper, magazine and billboard adverts and has provoked a lot of debate - what do you think about it? Here are some of the images:

Submerged London!



Tropical Birds in St Mark's Square, Venice, Italy!



Rio de Janeiro underwater!



The Great Wall of China buried in a sandy desert!



Tropical plants in Paris!

Here is the movie campaign:







Mel Young (New Consumer) has called for a boycott of Diesel’s clothing line. “Diesel is appealing the worst aspect of human nature – one of greed and selfishness. Perhaps the people who own Diesel might like to watch films of children dying in floods in Bangladesh, where existing floods are being exacerbated by climate change. It might just get them to understand that making ‘funny’ little advertising campaigns out of misery really is beneath contempt.”

And here's a comment from Alisha Fowler (Global Climate Change blog) "I still feel that these ads communicate to most that they should, rather than worry about weather changes we are experiencing, dress for the weather and consume to cope. The ads reinforce our short term economic thinking, conspicuous consumption - and ethnocentric lifestyle. Why worry about global warming, after all - if the ocean gets warm enough and rises enough - you can go to the beach right there in the big apple!"

WHAT DO YOU THINK ABOUT THE DIESEL CAMPAIGN?


Tuesday 1 April 2008

Climate Change - What is the greenhouse effect?

This sequence of lessons aimed to introduce the concept of global warming and to analyse scientific evidence. Thanks to Miss Gunstone and Miss Hayes for working with all the Year 10 groups to prepare presentations about the key issues.



The earth has warmed by about 1ºF over the past 100 years. But why? And how? Well, scientists are not exactly sure. The Earth could be getting warmer on its own, but many of the world's leading scientists think that things people do are helping to make the Earth warmer.


You need to be aware of several important definitions before we go any further...

Climate is the long-term average of a region's weather events, usually over at least 30 years.

Climate change represents a change in these long-term weather patterns. They can become warmer or colder. Annual amounts of rainfall or snowfall can increase or decrease.

Global warming refers to an average increase in the Earth's temperature, which in turn causes changes in climate. A warmer Earth may lead to changes in rainfall patterns, a rise in sea level, and a wide range of impacts on plants, wildlife, and humans.

When scientists talk about the issue of climate change, their concern is about global warming caused by human activities.

The Greenhouse Effect is the rise in temperature that the Earth experiences because certain gases in the atmosphere (such as water vapour, carbon dioxide, nitrous oxide and methane) trap energy from the sun. Without these gases, heat would escape back into space and Earth’s average temperature would be about 60ºF colder. There would be no life on earth under these circumstances.



The Greenhouse Effect is shown in the diagram above and in the YouTube movie below. The movie won't play at school as the site has been filtered by the LEA. Sorry!


If you are an auditory learner, you might like to listen to the Geocrest Podcast about climate change - Global Warning.

And finally, here is the an official video from the British Government.


Acid Rain

Objectives:

- to know how acid rain forms
- to recognise that acid rain is an issue of international concern
- to consider what we might do to reduce the impact of human activities in creating acid rain

This is the PowerPoint we used in the lesson. I've had to remove the movies as Slidehsare can't cope with them! However, just so you don't feel you're missing out, I have linked to several YouTube movies below.

Acid rain is a result of air pollution. When any type of fuel is burnt, lots of different chemicals are produced. The smoke that comes from a fire or the fumes that come out of a car exhaust don't just contain the sooty grey particles that you can see - they also contains lots of invisible gases that can be even more harmful to our environment.

Acid Rain is caused by the burning of fossil fuels. Burning oil, gas and coal in power stations releases Sulphur Dioxide (SO2) into the atmosphere. Burning oil and petrol in motor vehicles puts nitrogen oxides (NOX) into the atmosphere. These gases mix with water droplets in the atmosphere and create weak solutions of nitric and sulphuric acids. These then fall as acid rain.



Acidity is measured using a scale called the pH scale. This scale goes from 0 to 14. 0 is the most acidic and 14 is the most alkaline. Something with a pH value of 7, we call neutral, this means that it is neither acidic nor alkaline. Rain is always slightly acidic because it mixes with naturally occurring oxides in the air. Unpolluted rain would have a pH value of between 5 and 6. When the air becomes more polluted with nitrogen oxides and sulphur dioxide the acidity can increase to a pH value of 4. Some rain has even been recorded as being pH2.



Acid rain increases the acidity levels of rivers, lakes and seas which can kill aquatic life. It also increases the acidity levels of soils which can kill vegetation. Acid rain has been found to destroy the roots and leaves of forests in Germany and Scandinavia have been destroyed as the result of acid rain emissions from the UK.

Acid rain can also erode buildings and monuments (particularly if they are made from limestone like the statue below).



Acid rain can be carried great distances in the atmosphere, not just between countries but also from continent to continent. The acid can also take the form of snow, mists and dry dusts. The rain sometimes falls many miles from the source of pollution but wherever it falls it can have a serious effect on soil, trees, buildings and water.

Thanks to YouTube user Jamie Harris for this movie:


What can be done to prevent acid rain?

The main way of tackling the problem of acid rain is to reduce emissions. We can do this by:

• researching new ways to create energy which don't produce so much pollution

• spending more money on pollution control even if it does mean an increase in the price of electricity

• wash sulphur out of smoke by spraying a mixture of water and powdered limestone into the smokestack

• fit cars with catalytic converters which remove three dangerous chemicals from exhaust gases

• give greater subsidies to public transport encourage people to use public transport rather than always travelling by car

• make an effort to save energy by switching off lights when they are not being used and using energy-saving appliances - when less electricity is being used, pollution from power plants decreases

• walking, cycling and sharing cars all reduce the pollution from vehicles

Saturday 29 March 2008

What's happened to Google?


What's happened to the Google homepage?
Don't worry - it's not a mistake. The reason that Google has "turned the lights out" on its homepage is that it is supporting 'Earth Hour'. Last year, Sydney took a stand against climate change and switched off the lights for an hour on 31st March. This year, Earth Hour has become a global event. People across the world will be switching off their lights for an hour at 8.00pm local time on 29th March. Will you be one of them?


Monday 11 February 2008

How do weather and climate affect peoples' lives? Holidays in the Mediterranean

This lesson considered:

- how the Meditteranean climate differs from the UK climate
- why British tourists are attracted to the Med
- how the climate affects different holiday types

The vast majority of overseas holidays taken by UK residents are in EU Europe. The graph shows the percentage of outbound visitors to visit the top 10 destinations in 2003.


UK residents made a record 41.2 million holiday trips in 2003. This was 3 per cent more than in 2002 and was a continuation of the rise in overseas holidays over the last three decades from 6.7 million in 1971. About half (47 per cent) of the holiday trips abroad in 2003 were package holidays. Large numbers of families travel south during the school holidays, visiting the islands and mainland resorts of the Mediterranean. We considered the reasons for this...

1. Cost - flights to Mediterranean resorts are cheap.
2. Language - many British children are taught European languages at school; the vast majority of Europeans speak enough English to be able to comunicate with tourists.
3. Flight times - flights times are short, for example just 3 hours to Rome.
4. Low cost airlines - many new low-cost airlines have been established, and they are in competition with each other so bargain flights are available!
5. Internet bookings - widespread use of the internet has made it easier (and cheaper) to book holidays.
6. Weather and climate - many travel agents market the Mediterranean resorts as being in guaranteed sunshine. Is this the reality?


Make your own clipart like this @ www.TXT2PIC.com

These graphs show the average temperatures in the UK and Spain's Costa Blanca, and the average number of hours of sunshine. To what extent do you think UK travel agents are justified in using the slogan 'Come to Benidorm for your winter break!'. How does the Mediterranean climate differ from the UK climate?



If you were on holiday in Benidorm in the summer, what activities might you take part in? Sunbathing? Skiing? Look at the climate graphs for ideas! How would the activities for a family holidaying in Benidorm be different to those for a family holidaying in Scarborough?

How do weather and climate affect people's lives?

Weather and climate can have a major effect on people's lives, for example:

Farming - there is a direct link between the type of agriculture and climate. For example, Eastern England has a drier, warmer, sunnier climate than the west. Arable crops tend to be grown in the east, and pastoral farming dominates in the west.

Housing - in particuarly hot climates, buildings may be painted white to reflect the heat. Houses in cold climates are often built on stilts to insulate them from the freezing ground.

Clothing - there is an obvious link between clothing and climate! Why would you wear a snowsuit rather than a bikini if you visited the Arctic?

Sport and leisure opportunities - remember the Jamaican bobsled team of Cool Runnings? They weren't too successful! Why might this be?



Sources of energy - particularly windy areas have plenty of potential for wind farms.

Tourism - the next post considers this in more detail.

Water supply - most of the UKs population live in the south and east, which is relatively dry. Water has to be transferred from reservoirs in the wetter west.

Snow and Ice - in areas where snow and ice are rare, even a small snowfall can lead to chaos on the roads. Schools may even be closed for the day!

Anticyclone case study - Europe, Summer 2003

Thanks to Miss Wieczorek for her help in preparing the resources for this lesson.

The Summer 2007 exam paper required candidiates to write a case study about a high pressure weather system. The European anticyclone of Summer 2003 would be a great example to use in a question like this (remember: anticyclones are areas of high pressure).

This is the 2007 exam question. Make sure that you can answer in detail - check the previous post to see how the examiner marks case study answers.

A weather event caused by high pressure

(i) Name and locate a weather event that has been caused by a high pressure system.
(ii) Describe the weather event.
(iii) Explain how the weather event affected people and the environment.

These questions could also be answered using the Summer 2003 anticyclone in Europe:

A weather event (June 2001)

(i) Name a weather event you have studied.
(ii) Describe how the weather event affected different groups of people and the environment.
(iii) Explain why the weather event took place.

A weather event caused by a high or low pressure weather system (June 2003)

(i) Name a location where you have studied a weather event.
(ii) State whether the weather event was caused by a high or low pressure system.
(iii) Describe how the weather event affected people and the environment.
(iv) Explain what caused the weather event (use diagrams if you wish).

OK, now for the lesson materials - the PowerPoint and the MindMap:



Sunday 10 February 2008

Case study questions

Free Image Hosting at www.ImageShack.us

On the Higher Tier paper, the case study is marked like this:

Level 1 (1-2 marks) Provides simple description or explanation only.
Level 2 (3-4 marks) Provides an account in which description is accompanied by some explanation. Choice of case study applied reasonably well.
Level 3 (5-6 marks) Names an appropriate example. Provides a balanced account with accurate descriptive points and detailed explanation. Appropriate choice of case study applied well.
Level 4 (7-8 marks) Names an appropriate example. Provides a balanced account which includes specific detailed description and specific detailed explanation. Appropriate choice of case study applied very well.

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1. The overall quality of the geographical response is judged rather than the ability to make continuous points.
2. The higher levels and marks can be accessed by knowledge and understanding of greater accuracy and specificity e.g. referring to the advantage of increased access for deliveries by locating a shopping centre next to Junction 21 of the M1 motorway rather than just giving a reason as being next to a motorway.
3. If a candidate chooses to use as their case study any material taken directly from the examination paper resources, marks will only be credited for knowledge and understanding that could not have been taken directly from the examination paper.
4. It is possible to gain all the marks by drawing fully annotated sketch maps and/or diagrams for any case study. Sketch maps need to contain some explanatory labels to get beyond level 1; descriptive labels alone do not meet the explanation criteria.
5. To ensure coverage of syllabus breadth it is sometimes necessary to include an exclusion clause in the question e.g. from an MEDC, outside the UK or to specify a choice where another response is not wanted e.g. a weather event (i.e. not climate). In order to ensure that good understanding of Key Ideas and Questions being examined from that part of the Unit in that question receive some credit, candidates may still be awarded up to a maximum of half marks on each case study where the choice is inappropriate but related. This also applies if a relevant case study is discussed but not clearly named or identified where requested.

Anticyclones

This image shows an anticyclone over Spain on 31st January 1999. Notice how the sky is clear - this is a defining feature of an anticyclone.


Anticyclones are areas of high pressure. They bring settled weather. If an anticyclone is sitting over the UK in the summer, it's an ideal opportunity to head for the beach!

In an anticyclone, air descends and pressure increases. This brings very light winds (which blow outwards from the centre in a clockwise motion), clear skies and dry conditions (because the air is descending and warming up, there are no clouds and no rain).

Summer Anticyclones
Summer anticyclones bring hot and sunny weather due to there being clear skies (because of the descending air). The days are long and the sun high in the sky, which gives plenty of opportunity for the land to be heated up. These conditions could therefore lead to convectional rainfall occurring.
Winter anticyclones
Winter anticyclones bring clear days too. However the sun is low in the sky and the days are short, meaning you get cool, crisp days. Clear skies on a winter’s night will allow frost to form. The land quickly loses heat during the night, as there is no cloud cover to act as insulation. The rapidly cooling ground cools and condenses any moisture in the air above it, forming droplets of ice when the temperature falls below freezing. This is frost.
Fogs are also caused by clear winter nights. The ground loses heat. This cools the air above it causing moisture to condensate around dust particles in the layer of air closest to the ground surface. This is fog.
Thanks to YouTube user BlackDollarBills for this video about the features of summer and winter anticyclones:



This video will help you to remember the key features of anticylcones.
You should now be able to complete the worksheet about the differences between depressions and anticyclones. Click on the image to be taken to the task.





The Great Gale of the Millennium - Lothar and Martin - 25-28 December 1999



We studied the Great Gale as an alternative case study of the effects of a low pressure system.



Again, you need to be able to recall specific detail about the storms. Most exam questions focus on effects on both people and environment - it would be a good idea to organise your notes under these two headings. The PowerPoint we used in the lesson is reproduced below - you should use it to add detail to your notes.

Depression case study - The Great Storm of October 1987

On Paper 1/2, each question ends with a case study. This is worth 5 marks on the Foundation Tier paper and 8 marks on the Higher Tier paper. To score well, you need to include specific detail in your answer.



Questions about low pressure weather systems are common in the exam. You should use the case study handout sheets and the YouTube clips to add to your notes and then have a go at writing an answer to one of the following questions. In the exam, you will have about 8-10 minutes to write your case study.

A weather event (June 2001)

(i) Name a weather event you have studied
(ii) Describe how the weather event affected different groups of people and the environment
(iii) Explain why the weather event took place

A weather event caused by a high or low pressure weather system (June 2003)

(i) Name a location where you have studied a weather event
(ii) State whether the weather event was caused by a high or low pressure system
(iii) Describe how the weather event affected people and the environment
(iv) Explain what caused the weather event (use diagrams if you wish)

A weather event caused by low pressure (June 2005)

(i) Name and locate a weather event that has been caused by a low pressure system
(ii) Describe the weather event
(iii) Explain how the weather event affected different groups of people and/or organisations

















These clips are from broadcasts made for the 20th anniversary of the storm, in 2007:







Low pressure systems - depressions

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You need to know:

- what a depression is
- how it forms
- what it looks like on a satellite image and a synoptic chart
- the type of weather it brings

REMEMBER: a depression is a low-pressure system (if you are feeling depressed, you are sometimes said to be feeling 'low').

A depression forms when cold polar air meets warm tropical air at a front. The less dense warm air starts to rise over the colder air, and this starts to lower the air pressure. Depressions are common over the UK as we are on the boundary between the warm and cold air masses. They move from west to east across the UK, bringing rainy weather with them. The air in a depression blows anti-clockwise and upwards.

The boundary between the two masses is called a front. There are 2 fronts in a typical depression:

1. the warm front - this passes first, and has the warm air behind it (i.e. it is the front of the warm air). It is where the advancing warm air is forced to rise over the cold air

2. the cold front - this follows, and has the cold air behind it (i.e. it is the front of the cold air). This is where the advancing cold air undercuts the warm air in front of it.

On a weather map, the warm front is shown as red semi-circles and the cold front as blue triangles. To remember this, think about the colour on bathtaps (cold=blue, red=hot) and the shape of a lady's chest in hot/cold weather! The isobars are closely spaced, indicating strong winds, and the numbers decrease to a low in the centre. An occluded front is shown by alternating blue triangles and red semicircles.

The sequence of a depression

We used a mnemonic to remember this:

Chesterton Army Went Fighting With Sticks, Coleridge Fled Cowardly Away

which stands for:

Cold Air, Warm Front, Warm Sector, Cold Front, Cold Air

This mnemonic can also be useful when remembering the pattern of weather that a depression brings. This is shown in the PowerPoint below.



In class, we used Mr Cassidy's fantastic Postman Pat movie and PowerPoint to help us with the depressions topic. You can download the movie and presentation from here. It's a huge download (over 50mb) so may take a while - but it's definitely worth it!

We also used the interactive files from the NGFL in class. You can work through them here.

We didn't make out own movie about the passage of a depression, but if we had it would probably have turned out something like this one from Teale Green school.

What factors affect temperature?

You should be able to explain a variety of factors that affect temperature on a global scale, including:

- latitude (distance from the equator)
- altitude (height)
- continentality (distance from the sea)
- prevailing winds and ocean currents

Latitude

Latitude is the main factor affecting global climate - the further you go from the equator, the cooler it gets (all other factors remaining constant). This is because the earth in curved which means that the sun's energy is more concentrated at the equator. This, and the thinner atmosphere at the equator, means that the earth gets hotter here.

Altitude

Temperatures decrease by 1 degree celsius for every 100 metres increase in altitude. Mountainous areas are therefore cooler.

Continentality (distance from the sea)

The sea is cooler than the land in summer, but warmer in winter. This is because it takes the sea a long time to heat up, but it is slower to cool down than land.

Prevailing winds and ocean currents

The prevailing wind is the direction that the wind blows from most often. Winds take on the characteristics of their source region. Our climate in the UK would be much colder if the prevailing wind came from the north (the Arctic).

Ocean currents can be warm or cold, and they affect the temperature of coastal areas. The warm North Atlantic Drift keeps the British Isles warm in winter.

For a really clear summary of the main factors affecting global temperatures, download and read Robert Scott's essay. Robert wrote this essay when he was in Year 8!


Sunday 20 January 2008

The British Climate

gif animation

The British climate is temperate - this means that it does not experience extremes of temperature or rainfall. The climate can be divided into four sections.
In winter, the west is kept warm by the Gulf Stream whilst the east is cooled by air masses from continental Europe. In summer, temperatures are influenced much more by latitude.

These images show surface temperatures for January and July.





The four sectors are as shown here: