Geography Home Learning Booklet. Year 7. Glaciation and Geological Timescales

Transcription

1 Geography Home Learning Booklet Year 7 Glaciation and Geological Timescales Name Tutor Group Teacher Given out: Monday 18 April Hand in: Monday 25 April Parent/Carer Comment Staff Comment Target

2 Introduction please read me! Welcome to your Home Learning booklet for Geography. This booklet is focused on Glaciation. This is not something we have studied or are going to study in class until Year 8 so it s a really good opportunity for you to show how good you are at independent learning. There are 7 main tasks for you to try your best to complete. We do expect you to finish the booklet but also to finish it well and to try your hardest. You can use the after school help sessions on Tues, Wed & Thurs 3-4pm, ask teachers, or even work together as a family if you find it difficult to do everything well on your own. You might also need to use an Atlas from home/internet to do one of the tasks. Remember the booklet should take you 5 hours to complete. Work hard and enjoy your learning. Yours Mrs Perryman

3 All to complete Task 1 What is a Glacier? Fill in the gaps in the following paragraph using the words in the word box to make sense of what a glacier is. A glacier is a large body of and ice. We find them in high-up places (the Swiss Alps) and in places that are far or south, like the Arctic and. Each glacier has built up over many in places where snow has fallen but not. Snow turns to ice as it collects in. The weight of the ice means that it starts to slip mountain sides over time. As moving ice creeps into the climate of lowland regions, melting takes place. snow years down Antarctic layers warmer melted north

4 All to complete Task 2 Types of Glacier There are different sizes of glacier. These include: Ice sheets Ice caps Valley glaciers Look at a world map and you will see Antarctica and Greenland covered white. These are enormous ice sheets. If both melted completely, sea-levels around the world would rise by tens of metres! These are areas of mountains which are permanently covered in snow and ice. The Himalayas are a good example of this. On a smaller scale still, the Alps are home to ice-capped mountains and valley glaciers. Local glaciers can develop anywhere on Earth where the land is high and cold enough, including central Africa! Snow patches The smallest glaciers are little more than snow patches on mountain sides. They tend to be found on north-facing slopes where there is less sunlight received to melt the ice. The Highlands of Scotland has snow patches that last for much of the year, but no real glaciers. Match the description to the picture and write in the name of the glacier in the space underneath.

5 All to complete Task 3 Definitions of a glacier A glacier is like a gigantic river of ice that occurs in very cold places such as Antarctica, the Arctic and also in mountain regions. Look very carefully at each of the pictures and then use what you can see in the pictures to match it up with its definition on the next page. Ablation Glacier Terminus Accumulation Moraine Carving Retreat of a glacier

6 Crevasse Snout Term ablation accumulation calving crevasses glacier terminus moraine Definition Accumulations of rock debris being transported or deposited by a glacier. This term also refers to the landforms made of the debris after it has been deposited by the glacier. Where glaciers reach the sea or a lake, it is the process by which pieces of the glacier break off and float away. The gain of snow and ice in a glacier. This is usually from precipitation in the form of snow, but also includes snow blown onto the glacier from surrounding slopes. Occurs over a time period when ablation averaged across the whole glacier exceeds accumulation averaged across the whole glacier. The glacier becomes smaller and the end of the glacier goes back. The lower part of a valley glacier s ablation zone. The loss of ice or snow from a glacier. This can occur by melting, by evaporation, and by icebergs breaking off of a glacier if the

7 Extension glacier borders a sea or lake. retreat (of a glacier) snout Fractures (or breaks) that can be seen at the surface of the glacier caused by stretching (extending) of the ice. The downward end of the glacier. Task 4 Use your definitions Now that you have figured out what ablation and accumulation are try to match these definitions to their meanings; Term ablation zone accumulation zone advance (of a glacier) equilibrium line Definition Occurs over a time period when accumulation averaged across the whole glacier exceeds ablation averaged across the whole glacier. The glacier becomes larger and extends further. The boundary between a glacier s accumulation zone and its ablation zone. Along this boundary, averaged over the year, accumulation is equal to the amount of ablation. The lower area of a glacier where the rate of ablation is higher than the rate of accumulation. The relation between accumulation and ablation for a glacier (also

8 All to complete called glacier budget ). It is positive if over a year there is more accumulation than ablation. It is negative if there is more ablation than accumulation. mass balance The upper area of a glacier where the rate of accumulation is higher than the rate of ablation. Task 5 Annotation Study the photograph below of a small glacier in Washington State, USA, taken in July. Accumulation zone Equilibrium line Ablation zone Glacier terminus Now label in the same features shown above in this

9 generalised drawing of an alpine valley glacier in summer. All to Also label the area of the glacier that complete is called the snout and the surrounding moraine. Task 6 Aerial Photo Field Sketch Study this aerial photo showing part of a glacier in Antarctica. With a pencil, draw a simple sketch of the photograph in the box below it. On your sketch, label the glacier terminus, icebergs and crevasses. It might surprise you to know that glaciers also flow incredibly sloooooooowly downhill until they reach the sea. They are a bit like gigantic rivers of ice. Draw an

10 arrow to indicate the apparent flow direction of the ice. Task 7 How glaciers shape the landscape All to complete Can you suggest reasons for why the crevasses are located where they are on this glacier? Looking back at the photo of the Cirque glacier, can you suggest why the ablation zone of a glacier looks darker than the accumulation zone? Look at the pictures and try to make guesses to answer the questions based on your knowledge of Geography. Apart from the fact that one picture has ice in it and the other does not what differences can you see between the two photographs?

11 Why are the rocks sharp and jagged in the mountain photo and smooth and round at the beach? Notice the rocky debris along the sides of this glacier. Where has this rocky debris come from, and how do you think it got to the glacier? This is a photo from under a glacier. How do you think pieces of rock debris can get picked up by the glacier as it moves over the ground? Hint: there is melting and refreezing of water beneath glaciers. Can you describe the process that caused the scratches on this rock outcrop? Hint: glaciers move rocky debris inside and under them as well as along the surface.

12 All to complete One of these valleys was eroded out by a glacier. Describe the shapes of the two valleys and suggest reasons for the difference. Task 8 - What landforms do glaciers create? On this page you will find a table giving definitions for all the different types of landforms that you might find in a glacial landscape. Use this table to help you identify these landforms in the photos on the next few pages. Term Definition Arête Cirque (also called corrie and cwm ) A sharp, steep, and narrow ridge that results from glaciers in valleys next to each other. Armchair or bowl-shaped hollows on the sides of mountains that either contain (or used to contain) glaciers. Fjord A steep and narrow sea inlet which originated as a glaciated valley near the coast that became flooded by the sea as the sea level rose.

13 Glacial trough (also called U-shaped valley ) Hanging valley Steep sided, relatively flat and broad bottomed valleys that either contain (or used to contain) valley glaciers. Formed from a smaller valley glacier joining a larger valley glacier. Once the glaciers have disappeared, the valley that was being worn down by the smaller glacier is not as deep, and where it meets the main valley there is a sudden drop often containing a waterfall. Pyramidal Peak A steep, isolated peak formed from glaciers wearing away a mountain summit from three or more sides. Ribbon lake Truncated Spur Formed when a glacier melts and leaves behind long and very deep lakes made of melt water. Truncated spurs are rounded areas of land which jut out from the side of the valley and are then suddenly cut off because of a glacier. They are often rounded at the top but steep at the bottom. How many pyramidal peaks, arêtes and corries can you see in this aerial photograph of the Alps? Pyramidal Peaks Arêtes Corries

14 What glacial landforms can you see in this picture of Glencoe in Scotland? There are at least 3. This is an aerial view of the Lake District in Northern Britain. What evidence is there that this area used to have many glaciers? Use the names of the landforms to help you explain.

15 Extension This is Milford Sound in New Zealand which is a Fjord. This picture below shows the hanging valley that can be found there. Use the sentence starter to help you explain how you know that this is a hanging valley. The photograph shows a hanging valley because and also because Extension Map interpretation The OS map extract here focuses on Helvellyn and its surrounding area in the English Lake District. Helvellyn is one of the highest peaks in England reaching an altitude of 950 metres above sea level.

16 1) What evidence can be seen on the map and the image that this area was glaciated? 2) What type of feature of glacial erosion now contains the lake called Red Tarn? 3) From looking at the map extract, label the summit (highest point) of Helvellyn onto the second image. Also add labels for Striding Edge and Helvellyn Screes onto the second image. 4) Name two other landscape features of glacial erosion that can be seen in the map and the image, and describe their locations in relation to the summit of Helvellyn. 5) If you were to take a fieldtrip to Grisdale Valley what other glacial features do you think you would see?

17 Self Evaluation of my Homework I am a R learner. I know this because: I believe that my effort and attitude to learning for this booklet is a: I know this because: