Revision

The Dreaded Word

Geography Specification

The first thing that is really important for students is to actually understand what the examiners are looking for in the answers. I think I would actually give out an over view of the specification of that topic on the introduction lesson of Glaciers, so they can follow and mark their own progress.

I have attached a link to the specification that is given by the AQA exam board

 http://web.aqa.org.uk/qual/newgcses/geo_landt/new/geography_a_overview.php?id=09&prev=09

Please click on specification and the topic overview of 'Ice on the land' is on page 16.

Practice Papers

I hated doing these while conducting both my GCSE's as well as my A levels. But I could understand why they were so important, it highlighted my weaknesses in terms of subject knowledge and my skills in answering questions.

Again I have attached the link to the AQA website with some pass papers on and the answer booklets for students to practice their exam techniques.

http://web.aqa.org.uk/qual/newgcses/geo_landt/new/geography_a_materials.php?id=09&prev=09


PowerPoint Quiz using Hyperlink

I have burrowed this idea of creating a PowerPoint quiz using hyperlinks from my Primary school placement and I figured that if Year 6's can do it then maybe some body as computer illiterate as me might be able to have a go.

The idea is that students create an interactive quiz that uses their knowledge of Glaciers. If they get answers right they move onto the next screen if they do not they go back to the beginning.
If I have time, I will create a PowerPoint quiz.

This is again to use different methods to help students identify where they need to put some extra revision in or area's they need one:one tuition from the teacher.

Glaciation and Climate Change

I think thats it is really important for students to understand that Glaciation is not an event that occurs solely on its own. That it is not affected by anything or affects anything else. I am contentrating on Glaciers and Climate Change, as it probably has the most obvious connection but do not fooled there is connections to a lot of other topics in Geography. Such as:-

• Glaciers and habitats
• Glaciers and Toruism and Economy
• Glaciers and other Hazards

Glaciers and Climate change

Previous eras of change in Climate

Scientists from the round the world use Ice Core to help uncover a long term climate record. They extract ice from Glaciers to analysis data that is stored with the Ice. Especially the particles trapped in the air pockets with the Glaciers, they are literally containing old atomosphere. There are able to aid scientists in constructed  and record changes in past climate and vegetation that would have been there.

Please see link below of a BBc report in 2004 of an Ice core that allowed scientists to gain information from 740,000 years ago.

http://news.bbc.co.uk/1/hi/sci/tech/3792209.stm

Also in the report it indicates that the carbon dioxided are higher than they have been in 440000 years. This leads nicely on to the next point.

Glaciers and Global Warming

Today scientists are looking at how our climate warms up,whether its natural or man made. Since the Industrial revolvtion our Glaciers have mainly followed a pattern of retreating and increased levels of retreat over the last few years.

'In Europe, the situation is worrying too. Europe’s glaciers are thought to have lost around a quarter of their mass in the last 8 years' (http://www.bbc.co.uk/climate/impact/glaciers.shtml)

'It is believed the situation is so extreme in Alaska that of the 2,000 glaciers observed, 99%of them are retreating' (http://www.bbc.co.uk/climate/impact/glaciers.shtml).

The earth's temperature is on the rise and Glacier retreat is used as evidence that this is ocurring below it a link for a video that explains really well the affects Global warming has on Glaciers. I have also added the website of the National Geographic as there are a lot of video's on the website showing evidence of Global warming.

Video :- http://video.nationalgeographic.com/video/player/environment/global-warming-environment/way-forward-climate.html

Website:- http://video.nationalgeographic.com/video/player/environment/global-warming-environment/


One of the biggest retreats in the last few decades is Franz Josef Glacier in New Zealand. It dramatically retreated in the 20th century, on the link below there is pictures that show the Glacial retreat over 14 years:-

http://nsidc.org/glaciers/gallery/retreating.html.

Not only is the Glacier melting, they are causing a vast amount of meltwater all over the world. This will cause a rise in the level of rivers and oceans,that have worldwide impacts such as flooding low laying land.

There is loads of information on how Glaciers are affected by the changes in climate and are excellent indicators as to the changes in the Climate. I could have gone into far more detail, however I just wanted to illustrate that all topics are inter linked.

Resources
http://nsidc.org/glaciers/questions/climate.html

http://www.bbc.co.uk/climate/impact/glaciers.shtml

http://nsidc.org/glaciers/gallery/retreating.html

http://www.nationalgeographic.com/

 





AMAZING TASK FOR STUDENTS

My old Geography teacher gave me this little recipe when she found out I was conducting a blog about Glaciers. I thought this would be a creative and quite a unique activity for the students to be involved with. I could image have amazed students would be as that was my first reaction.

Glacier Recipe

Mix 1

A 20oz Cup

1x stirring stick

3/4cup of warm water

1 cup of white glue

In the large cup add water and glue. Stir unti lwell mixed

Mix 2

A 8oz cup

1/2 cup of warm water

2tsp of Borax powder

In the cup, add borax powder and the water together. Still until the powder has dissolved

Pour mix 2 into mix 1. Stir until a glob forms and most of the water is mixed in. Knead and work the mix for 2 -3 minutes. If you do not use mix straight away, keep in an air tight bag and will last for a few months.

Task

The students will have to create a mountain like sculpture for the mixture to come down. The idea is that the mixture will move down the slope slowly, in the same manner as a real Glacier.

I am not sure this works as I am yet to try it out, but the theory behind getting the students involved in creating a model that represents a Glacier is a good theory.

Case Study: Lake District

In the National Curriculum it is important to not only know the theory of Glaciers but can relate it to actual places. Through my research one place that comes up regularly when I was looking at Erosion and Deposition features was the Lake District.

I think that this would be a perfect case study to use when describing features left by a Glacier, as a lot of Students may have already visited there but also could be used as a field trip opportunity to visit Glacier features in a real life setting.

For example this is:-

This is Red Tarn, Helvellyn that shows a lake within a Corrie. In these images you can see characteristics of old Glaciers that were here such as steep back walls and Aretes.

http://www.helvellyn.com/Gallery1.html

 

There is many more examples of Glacier feature in the Lake District. For this dramatic scenery, the Lake District attracts hundreds of people to the area. For Long Weekend breaks, walking holidays, trekking and cycling. This is a massive boost for the area's economy and local businesses.

I know this was a small case study, however everything here I have already covered. It just allows Students to have a specific place to talk about in Coursework or Exams

Resources

http://www.lakedistrict.gov.uk/

www.sln.org.uk/.../Glacial%20features%20of%20the%20Lakes.ppt

http://www.helvellyn.com/

Tasks for Students

Using this case study I would like them to them to do a tourist brochure on the Lake District and what people can see them and why.

I think its good that Students get a chance to write or design different modes of Information. It gives tham a chance to be creative as well as write a informative piece of writing.

Case Study: Iceland

Researching Glaciers, I found so many case studies that I could have focused on for an in-depth study. Each one having unique features that were fascinating. The reason I choose this one is because its a recent event that has happened and the children may have even been affected by it. I also think that its an excellent example of how Human and Physical merge together and affect each other.

Eyjafjallajoekull,Iceland

14th of April 2010



Location map

http://news.bbc.co.uk/1/hi/world/europe/8624748.stm


On the 14th of April 2010, a massive Glacier flood hit Southern Iceland. The Eyjafallajoekull Glacier is situated 75 miles away from Reykjavik, the capital city which is shown on the map.

This Glacier flood was caused by the Eyjafjallajoekull Volcano erupting underneath a 650 foot thick block of Glacier ice on top of the vent. This caused the ice to melt and quickly become a fast flowing river of water. The Volcano is quite steep, so the floodwater came down powerfully and in a very short amount of time.

This was not the first eruption from the Eyjafallajoekull Volcano in the area recently. On the 20th of March 2010 the first eruption happened, this was the first eruption in 200 years for the Eyjafjallajoekull Volcano. There was some follow up eruptions however many thought that the Volcano had quieten down. These presumptions were proved wrong when on the 14th of April there was an emergency night time evacuation of around 800 people in the flood zone area, which was a small town called Hvolsvollur and rural homes that surrounded the Glacier. The previous eruptions did not cause flooding as the active vents were in a mostly Glacier free areas of the landscape.



http://news.bbc.co.uk/1/hi/world/europe/8624748.stm



The vast amount of water caused local rivers to rise as much as 10 feet, which caused massive floods and the water continues to gush into the ocean. Huge amounts of infrastructure has been weakened or destroyed by this floodwater, such as bridges being damaged and coastal roads that lead to Reykjavik being washed away. There was also a lot of flooding in farm areas leaving them isolated, which is threatening many livelihoods.

One main consequence that caused major distress to Iceland and many other areas of Europe, which was the main reason I choose to do this case study, was the huge plumes of ash that the Volcano caused. The Volcano shot smoke and stream hundreds of metres in the air, which blew across a lot of Europe.

This caused major problems in Iceland as locals were told to wear masks when the ash falls, as its so thick and can cause many respiratory conditions. On the BBC news website, there was an interview conducted with one of the locals for their report, her name was Hannah Andrews.She told BBC that the government of Iceland have recommend that she would be wise to keep her cows and life stock indoors, as the smoke and ash could be lethal if her life stock breathed it in (http://news.bbc.co.uk/1/hi/world/europe/8624748.stm).

This could be devastating for farms as they are not only having to relocate life stock but as previously mentioned they are already struggling with being isolated by the flood.

It also caused massive problems for aviation. The smoke and ash forced many cancellations of flights across Iceland, UK and northern Europe and disrupted all air traffic.

The was some 'positives' (and I say that in a loose term) to the Glacier Floods, as of yet there was no cases of any causalities. The preparation  of the emergency services and the observation teams that monitor the Glacier was first class. They managed to evacuate a huge area without incident.

The biggest positive from this event is the increase of Tourism to the area, which if reports are to be believed on the economic status of Iceland, it is a much needed boost to the economy. Since the first eruption of Eyjafallajokull Volcano,there has been swarms of tourists eager to visit the island that is appropriately named the 'Land of Fire and Ice'. The number is around 25,000 extra people visiting Iceland, wanting to see the dramatic landscapes and the huge gushes of water that was caused by the Glacier flood.

I can not seem to copy and paste the actually videos from You Tube but I have attached the links below. I think these video's can actually show Students the affect of Glacier Floods.

This first link is a BBC report about the Glacier

http://www.youtube.com/watch?feature=player_detailpage&v=L7NamDwfXvk

This second link is to a report about the Air traffic disruption across Europe.

http://www.youtube.com/watch?v=hkdDRM_kTcY&feature=player_detailpage


In the future there are fears that there may be more eruptions from the Eyjafallajokull Volcano or these could agitate a neighbouring Volcano.

I think this is a great case study, as it merges both Physical and Human Aspects together. You could take any aspects of this case study and look at aspects in more detail from Iceland's Economy to people's health.

Resources
 www.bbc.co.uk/news
www.nationalgeographic.com
www.youtube.com


Tasks for students

I purposely did not set this report out in my 5W's which I raved about at the start of my blog. I thought it would be a good way for the students to learn if they received a report like the one I've written and using other resources on the Internet to answer the 5W's themselves. Also for them to think of primary and secondary affects of the Glacier Floods.

Glaciers as a Resource

Following on from my previous post, I am now going to focus on Why a Glacier is a resource for people.

Refrigeration

This is considered to be one of the earliest uses of Glacier Ice. Caves within Glaciers were used as stores to preserve food and ice cut from the Glacier was commercially and domestically.

In the 1850's, Ice from Alaska was transported to California and Ice from Glaciers in Southern Peru was exported as far north as Peru. Norway was exporting Glacier Ice before refrigerators were invented. Not only was Glacier Ice used as a simple way to preserve food, it was classed as an valuable commodity. This statement I also true today, Iceland market this Glacier Ice and melt water as a unusual form of pure mineral water. Peru grind the Glacier Ice and add different flavours to it, to create a form of natural snow cones.

Water

Glacier are a natural source of one of humans basic necessities. Not only is melt water a natural source of pure mineral water, the run-off is also used in many other ways for human survival.

Sources of Rivers:- Glacier melt water run off is the source of many of the worlds major Rivers. The Gangotri Glacier is the source of the Ganges River. Not is this huge River a water supply for many people, the source has actually become an attraction for tourists and pilgrims. This human activity is actually being blamed for it rapid retreat.

Irrigation:- Many arid areas, including the Thar desert and the Atacama desert receive the water for their irrigation for crops from draining Glacier melt water from adjacent mountains.

This is not a new concept or one that is restricted to arid areas. In Switzerland's Rhone Valley, for centuries farmers have channelled Glacier water to irrigated their crops.

Power

One of the most recent developments to make use of Glacier melt water run off is Hydroelectric Power. Scientists and engineers in Canada, New Zealand and Europe have worked together to find ways of tapping into the massive potential of using melt water as a form of renewable energy.

Norway is one of the more innovators in this field, 1877 was the first time hydroelectric power was used in Norway . Today, approximately 99% of electricity is from  hydroelctric power schemes,of which a big proportion of this hydroelectric is from Glaciers. There are many projects going on in Norway but here is a link to the Svartisen Hydroelectric Project, which is an interesting website to understand what goes on in this Hydroelectric plants.

The Svartisen Hydroelectric Project : - http://www.robbinstbm.com/case-study/svartisen/

Tourism

Increasingly tourism has become a major feature when thinking about Glaciers. Countries have gone to great lengths to attract tourists to these areas, as it boosts the local economy.

With walkers and mountain hikers these areas have always been popular due to the challenging landscape and the beautiful unique scenery. When there is fresh snow on Glaciers, they provide opportunities for skiing. Skiing resort are a massive tourist destination, that attract people from all over the world. Using this crevasse free Glaciers as ski resorts, main that in some places skiing can occur around the year.

 Another big tourist attraction is guided Glacier walking, this attracts people of all ages to try a new incredible experience. This is something that I can say I have done at Franz Josef in New Zealand and this unique experience was a once in a lifetime activity. Below is some images of me attempting to climb Franz Josef:-

 Here is the website that shows you the main home page of Franz Josef and the way they are attracting tourist to the area:-  http://www.franzjosefglacier.com/

Sources:-

Other than the main websites I have highlighted throughout the Blog, here are some general websites that talk about Glaciers as a resource.

http://nsidc.org/glaciers/questions/people.html

http://www.nature.nps.gov/views/KCs/Glaciers/HTML/ET_Monitoring.htm



Tasks for Students:-

As in the previous posts, I do not want Students to think about this 'human' impacts as purely Human Geography. So to make them think of Glaciers as having both Human and Physical aspects, I would like them to devise their own advantages and disadvantages of using Glaciers as a resource.

A way to possibly expand on the Students theories on advantages and disadvantages, is to conduct a class debate. A group on the side of using Glaciers as a resource and the other as why they should not be used. Possibly having another group as the judges and vote of which group had the best arguements and had reasons and examples to back up their points.

Glaciers as a Hazard

I would just like to point out a really useful book that has helped me out greatly in this section and the next section. Its by a gentlemen called Peter Knight, who is an University Professor at the University of Keele. I read his book Glaciers (1999) however he has done many other academic writing and published more recent work.

In this section, I am going to write about how Glaciers are classed as a Hazard.

Ice Avalanches

Ice avalanches occur in a similar fashion to landslides and snow avalanches. In some cases Ice avalanches occur in conjunction with landslides and snow avalanches but also with other natural hazards such as earthquakes.

When Ice breaks away from the main Ice sheet, whether its by an earthquake or where the ice has moved past the bed rock underneath, the affects are disastrous. With modern technology and the Glaciers slow movement, their movement patterns are fairly predictable and are fairly rare. However when Ice Avalanches have happened its been at a great cost.

On the 10th of January 1962, a mile and a half long chunk of Ice separated from the 180 foot thick ice cap in the Nevados Huascaran valley in the South American Andes. The 4 million tons of Ice fell down the mountain, bringing with it, dirt and rocks from the slopes. In the space of 15 minutes, the ice avalanche travelled 11 miles. Once the avalanche had stopped the realization of the disaster was truly appreciated, a total of 7 villages were buried under the snow and a death toll that scientists can only estimate of around 4,000 people.

There was an avalanche in 1970 in the same area of Peru, that was the most catastrophic rock-ice avalanche known in history. That was caused by an earthquake with a magnitude of 7.7, this avalanche was huge in size and claimed the lives of 18,000 people.

Below is an image that shows the distance the two avalanches covered:-


http://maps.grida.no/go/graphic/ice-avalanches-of-the-nevados-huascar-n-in-peru

  Please use the links below to see more about the case studies:-

UNEP websitehttp://maps.grida.no/go/graphic/ice-avalanches-of-the-nevados-huascar-n-in-peru

and also
http://library.thinkquest.org/C003603/english/avalanches/iceandrock.shtml

Floods and Lahars

Glacier floods are considered among the most damaging hazards as they are an outburst of a vast amount of water. Also Glacier floods are very unique to each individual Glacier and may not cause any damage for years. Like Avalanches, Glacier floods can be caused by a numerous amount of reasons. In the Swiss Alps, Glacier floods occur approximately every two years by an outburst from ice-marginal lakes and the rapture of water pockets with in the Glacier.

However the a recent Glacier flood happened in Iceland on April 14th 2010 and began for a totally different reason. I will be writing about this Glacier as one of my in-depth case studies. Please see a future post...

Fluctuations and Surges

In an era when our climate is rising, it is unusual to think that any Glacier would be growing or surging forward. However this was a major hazard during the little Ice Age between the 13th and 19th Century.

The early settlers in Iceland, set up new settlements near Glaciers and when the Glacier grow it demolished the newly built towns. In modern development there is a proximity zone around Glaciers to prevent this hazard from occurring.

 As Glacier movement is slow and predictable, growth is not considered a immediate problem, however surge can be quick and surprising. A surge is a short lived event when a large amount of ice moves or slides forward, this can cause other hazards such as flooding.

The above image shows the surge of the Medvezhiy Glacier in Tajikistan, from June 3rd 2011 to 23rd of July 2011 the Glacier slid abruptly around 800 - 1000 metres. The Glacier normally moves around 200 - 400 metres a year. Glaciologists are concerned about Glaciers outbursts, as the Glacier is now blocking the Abdukagor River. It is causes a lake behind the ice sheet, infrastructure has already been damaged by one outburst already.

Please see the link to the Earth Observatory website below for more details on this case study:-

http://earthobservatory.nasa.gov/IOTD/view.php?id=51498 

Tasks for students:-

I think that it is really important that students do not just see these hazards as a physical occurrence. Using mind maps, I want the students to think carefully about have these hazards do impact on humans.

Who does the Glaciers effect????

This is my last but by no means least 5th W that I set my self out to answer at the start of doing this blog.

I am writing this post to set out how am going to answer the above question. I think that doing this section in a methodical manner will allow a better flow to the blogand I consider this section to be really important. The information I set out here will be the information the students will need to answer the higher mark questions and be able to gain the higher levels.

Plan

1. Glaciers as a Hazard
2. Glaciers as a Resource
3. An in-depth case study of an area where a Glacier has retreated.
4. An in-depth case study on a Glacier.

This we most likely change as I start writing the actual blog. But here we go...

New glacier theory on Stonehenge

Whilst doing my research into case studies, I found this news article on BBC news website. I thought it was a interesting piece of fairly recent news on Glaciers, hopefully it will show students that Glaciers is just as recent in modern day as thousands of years ago.


The link for this article is below:-

New glacier theory on Stonehenge

The debate over how the stones arrived at Stonehenge continues A geology team has contradicted claims that bluestones were dug by Bronze Age man from a west Wales quarry and carried 240 miles to build Stonehenge. In a new twist, Open University geologists say the stones were in fact moved to Salisbury Plain by glaciers. Last year archaeologists said the stones came from the Preseli Hills. Recent research in the Oxford Journal of Archaeology suggests the stones were ripped from the ground and moved by glaciers during the Ice Age. Geologists from the Open University first claimed in 1991 that the bluestones at one of Britain's best-known historic landmarks had not come from a quarry, but from different sources in the Preseli area. The recent work was conducted by a team headed by Professor Olwen Williams-Thorpe, who said she and her colleagues had used geochemical analysis to trace the origins of axe heads found at Stonehenge and this backed up the original work. There has been a great reluctance to allow facts to interfere with a good story Dr Brian John "We concluded that the small number of axes that are actually bluestone derive from several different outcrops within Preseli," she said. "Axes found at or near Stonehenge are very likely to be from the same outcrops as the monoliths, and could even be made of left-over bits of the monoliths." The research Archaeologists claimed the stones came from a quarry at Carn Menyn Dr Brian John, a geomorphologist living in Pembrokeshire, said he always thought the idea that Bronze Age man had quarried the stones and then taken them so far "stretched credibility". But he said the debate would go on until someone was able to prove beyond doubt what happened one way or the other. "This is very exciting, and it moves the bluestone debate on from the fanciful and unscientific assertions of the past," he said. "Much of the archaeology in recent years has been based upon the assumption that Bronze Age man had a reason for transporting bluestones all the way from west Wales to Stonehenge and the technical capacity to do it. "That has been the ruling hypothesis, and there has been a great reluctance to allow facts to interfere with a good story. "Glaciers may move very slowly, but they have an excellent record when it comes to the transport of large stones from one part of the country to another."

http://news.bbc.co.uk/1/hi/wales/south_west/5072664.stm

Glaciers in the Classroom

I feel that my blogs have been a lot of information, so I wanted to take some time out before I write about case studies to suggest some tasks for students to do in the Classroom.

From experience I have from the classroom and research I been doing, I think that doing little activities half way through the topic is beneficial. It allows students to test their knowledge and highlight any areas there are unsure of before going any further. Also it allows the teacher to indicated any weaknesses in the students subject knowledge.

Task 1:- Discussion

I maybe should have highlighted this at the beginning, however here is just as good.
Before I teach my class anything about Glaciers or even mention the topic name, I think its always important to engage them first and see what they actually already know about a topic.

I would show a general image of a Glacier and ask them what they thought about it? and What they could see in the image? What topic they thought we were covering?

Its just a nice introduction to the topic and students get to share their own prior knowledge.

Task 2:- Match the Pair.

This activity means that students can independently or work as a group to figure out what pictures go with the explanations. For example I would give the students pictures of deposition and erosion features made by Glaciers and also a sheet of a brief summaries of how these features occurred. All the children have to do is match the pair.
It may be very simple and not the most hi-tech activity but I think its a quick task that allows children to step away from writing. Also it allows students to talk to each other about the topic and work as a team to understand the features.

Task 3:- Recap Slide

This slide  is just to recap the important information we should know before we move on. It allows needs to be a list but its to make sure every people understands the topic.


Task 4:- Practical Activities

I have indicated some practical activities that the students could do throughout older posts, however I am going to suggest them again and other options.

Different children learn better in certain ways, I tried to include images in my posts to engage the children who are visual learners. Although I think that Practical lessons/ homework will engage most of the class.

Challenge:- Present to the Class a study of an feature caused by deposition or erosion??

Having an open question like this allows the students imagination to go wild. They could present their work in the following:-

Power point presentations: - I think that these are a generally good tool across the board in all topics and all subjects. Giving the students a chance to be in charge of their own learning. Being able to present their findings in their own and choosing an area that interests them.

Models:- I think its such a great idea to allow students the opportunity to make things. Being able to draw or model a feature would be an interesting way for them to learn. It would make students really responsive to the topic and I think they will really enjoy it when they present their features to the class.

Deposition Landforms

Well the title might explain, Deposition Landforms are the features that occur when material form the Glacier is laid down. Whether its when the Glacier is still there or once it has retreated.

Rock Flour and Till

Rock Flour:- Rock sediment that has been grounded down to a fine powder. This usually flows out of a Glacier by meltwater streams.

 Till:- refers to an unsorted variety of sediment, clay, gravel and rocks that has been deposited by the Glacier.

Erratics

Unlike River deposits, Glacier deposits are angular and mixed up. Large rocks and boulders can be found on their own rather than in groups, but also they can be found located with other types and sizes of rock. These Erratics are usually a rock type that is uncommon in the area that they have been dumped, for example Erratics that have been found in Norfolk originated in Norway. This helps Glaciologists determine the direction of ice flow and monitor past ice movements across large areas.



http://www.geulogy.com/norfolk/merton-stone-norfolk.html



This image is of The Merton Stone, Norfolk. It is considered to be one of the largest Erratic in England.

Drumlins

Drumlins are elongated hills of Glacial deposits, most commonly Till. They can be up to 1km long and 500 metres wide, and often occurring in groups that are known as a swarm or a basket of eggs. These would have been the debris collected and accumulated under the Glacier, when the Glacier became overloaded with debris and sediment, it would have been deposited. Even though Glaciologists still disagree on exactly how Drumlins are created, they help to indicate the Glaciers movement. Shown in the below diagrams of a Drumlins cross section, one side is quite steep while the other end tapers to the ground, showing the direction of movement.



http://www.bbc.co.uk/schools/gcsebitesize/geography/glaciation/glacial_deplandrev1.shtml



Vale of Eden in the Lake District



I have also added an image of how a Drumlin looks in real life. This was also found on the BBC Bitesize website.



Moraines

When a Glacier melts or retreats, different types of rock are laid down that have been carried along by the Glacier. These deposit piles are called Moraines, there are different types of Moraines depending on where they were deposited.

• Terminal Moraine:- Deposited at the furthest point that the Glacier reached
• Lateral Moraine:- Material that is deposited along side the Glacier, on the side edges.
• Medial Moriane:- Are found at the Junction of two seperate Glaciers that run along side each other.
• Ground Moraines:- are disorganised piles of different types rocks that have no obvious features. These rocks may have been washed out by Glacier meltwater streams or left in situ when the Glacier melted.

Below is a diagram used on the BBC Bitesize website, to illustrate the different types of Moraines:-

http://www.bbc.co.uk/schools/gcsebitesize/geography/glaciation/glacial_deplandrev2.shtml



Glacial Erosion Landforms

Glaciers make a huge impacts on landscapes, they exert vast amount of forces on the land. This causes dramatic changes caused by erosion.

Corries or Cirques

Corries are often the starting point of a Glacier. I'm adding a diagram here, so my explanation hopefully will make more sense. The diagram is from BBC Bitesize revision site



http://www.bbc.co.uk/schools/gcsebitesize/geography/glaciation/glacial_erosionrev1.shtml



Snow is captured in a hollow, and over a certain of amount of time this will turn into Glacier ice. As the ice is trapped in a hollow, it is unable to move downhill but gravity will still make the Glacier move. This circular motion within the ice is known as rotational slip and can cause the ice to pull away from the back wall and causing a crevasse.

Plucked debris from the back wall causes further erosion and which deepens the corrie and causes the hollow to get bigger and bigger. Some of this debris is deposited at the end of the Glacier and builds up a lip.

These processes create a rounded shaped hollow with a steep back wall, looks like a armchair. When the ice in a corrie melts, a lake is created within the hollow. This is known as a Tarn. An example of a Tarn is shown in this picture, its an image of Red Tarn on the eastern flank of Helvellyn in the Lake District.

http://www.bbc.co.uk/schools/gcsebitesize/geography/glaciation/glacial_erosionrev1.shtml.

Glacial Troughs

Glaciers cut out distinctive U-Shaped valleys  into the Landscape, this valleys are probably the most remembered landforms made by Glaciers, as it is a very common sight around the world. U-shape valleys are characterised by having a flat floor and very steep sides, This is caused by Glaciers moving through an already existing V-shaped valley caused by a river. The Glaciers force will erode the valley so it becomes wider, steeper, deeper and smooths down the sides. Below is an image of U- shape valleys, again found from the website bbc bitesize.

Great Langdale Valley, Lake District

Like Rivers, Glaciers have tributaries. As the main Glacier erodes deeper into the valley, the tributary is left higher up the steep sides of a Glacier. These tributaries still cause a used U-shape valley ending with a water fall at the cliff face are called Hanging Valleys. Below is an image of a Hanging Valley

http://www.scalloway.org.uk/phyl12.htm

Unlike a river, which erodes softer rock to make an easier route, which causes interlocking spurs. As the Glacier has so much weight and pressure, the Glacier will erode the valley which causes Truncated Spurs. The sloping edges from a interlocking spurs are cut off, as the Glacier tends to move straighter.

These U-Shape Valleys flow all the way to the coastline, when the Glacier melts the valley becomes flooded with sea water. This is known as a Fjord, Fjord's are common along Norway, Alaska, New Zealand, Greenland and Scotland. Below is an impressive image of Fjords in Norway


http://www.fjords.com/

Aretes and Pyramidal Peaks

Arete:- Is a knife edge ridge. It is formed when two Glaciers Corries run back to back or side by side. As each Glacier erodes either side of the the ridge, the ridge becomes steeper and the edge becomes narrower. E.g Striding Edge found in Helvellyn in the Lake District.

Pyramidal Peak:- Is formed with 3 or more corries and Aretes meet. The Glaciers have carved away at the top of a mountain, creating a sharp pointed summit. E.g Mont Blanc and Mount Everest.

Valley Floor Landforms

As the Glacier flows over land, it will meet harder and softer types of rock. Where the rock type is softer, the Glacier will erode a deeper trough than the harder, more resistant rock. When the Glacier melts, water will be left in this deeper troughs and form thin lakes called Ribbon Lakes. The areas of harder rock are called Rock Steps.

If a Glacier hits a particular resistant rock, it will flow over and around the rock. This leaves a smoothed rock mount, this comes in two types:-

Roches Moutonnee:- Often have steep, jagged faces created by plucking on the far side and a gradual incline which is smoothed by abrasion on the other side. Below is an illustration on how a Roches Moutonnee occurs

http://www.bbc.co.uk/schools/gcsebitesize/geography/glaciation/glacial_erosionrev4.shtml

Crag and Tail:- This is typically larger than a Roches Moutonnee. This works opposite to a Roches Moutonnee, as it hits the more resistant rock first and protects that rock behind it. Edinburgh is a perfect example of a Crag and Tail. Below is an illustration of how Crag and Tail occurs, again from the BBC Bitesize website.

http://www.bbc.co.uk/schools/gcsebitesize/geography/glaciation/glacial_erosionrev4.shtml

How does Glaciers affect the Landscape?

Glacial Processes

After studying What and Where Glaciers are, I am now going to look at how Glaciers shape and affect the landscape around them, this process is know as 'Glaciation'. With the weight of Glaciers and the gradual movement means that Glaciers can drastically change the land and cause new and unique landforms.
The Three processes by which glaciation affects the landscape is erosion, transportation and deposition.

Erosion

WEATHERING:- The most common form of erosion that Glacier's cause on the landscape if Freeze-thaw weathering. This is the action of glacial water getting into cracks,holes and joints within the rock, when it freezes it causes the rock to expand and widen. When the temperature heats up, it causes the water the melt and the rock contracts. Eventually this process cause pieces of rock to break off.

PLUCKING:- Plucking occurs when loosened fragments of stones and rocks, become frozen to the ice. When the Glacier moves, the stones are literally plucked from the ground, it leaves behind a jagged landscape.

ABRASION:- At school I always remembered this as the sand paper effect and in term of Glaciers its no different. Stones and rocks are embedded into the Glacier and as the Glacier moves the rocks rubbed against the bedrock and wears it down. It produces polished bedrock surfaces, that has scratches on.

There is more erosion processes that occur within Glaciation, however I have highlighted the most predominant processes.

On the BBC bitesize revision pages, I found this clip that I thought simply explained what a Glacier is but erosion processes as well. Please click on link below to watch.

http://www.bbc.co.uk/learningzone/clips/3079.bb.wmv.

 



Transportation

Glaciers are capable of moving large quantities of rock fragments and soil debris across huge distances. The distances all depends on material and the speed of movement of the Glacier. It is also important to put out here that Glaciers do not just move deposits from erosion, it may come from external sources such as:-

• Rockfalls from weathering off other slopes
• Avalanches
• Wind-blown materials, such as ash and dust.

Deposition

The intense erosive actions produces large amount of sediment that can be transported by the movement of the Glacier. The deposition of sediment can be laid down miles away from their origins.

The collective name for all the sediments and debris deposited under all glacial conditions is Glacial Drift.

However Geographers have classified glacial sediment according to its mode of deposition:-

Fluvio-glacial - Sediments that were deposited by melting ice or by glacial streams, meltwater is abundant in warm based Glaciers.

Glacier Till - This is when debris is deposited directly by the Glacial, dropped 'in situ' by retreating ice. 

The below diagram shows the classifications of sediments in deposition.



http://cgz.e2bn.net/e2bn/leas/c99/schools/cgz/accounts/staff/rchambers/GeoBytes/AS%20A2/A2/Glaciation.Web/glacial_deposition.htm



The When and The Why?

When did the Glaciers Occur?

The WHEN question is one of the 5Wquestions that I have set out for myself to answer. However doing my research. I have realised that this is a toughie, as there is no answer for this.

As previously stated Glaciers currently cover 10% of the world's land surface, however this Glacier Ice has been on the land surface for hundreds of years and it is only being sustained by annual precipitation.
Majority of the Glaciers that is currently around may have originated from the Last Ice Age, when Glaciers covered 32% of the land area. As the world has warmed up, the Ice has been melting. (this issue will be looked at in a later post), this is when Isostatic adjustment occurs. As the pressure is released from the shrinking Ice, the land is rising, as the pressure from the original Ice pushed the land surface down.



Why Do Glaciers Form

I have actually answered this question in my section of  'What is a Glacier', however I am going to go through it again. As repetition can sometimes be a goo thing.

When snow falls over hundred years and the climate of the area allows the snow to settle without melting or evaporating the snow. The pressure of the snow compresses together and forms a large Ice mass.

When Glacier Ice appears blue, it means that the ice is very dense. Years of compression makes the ice denser, as it pushes out any air pockets between the ice crystals. This dense ice does absorb all the colours of the spectrum but it primarily reflects Blue as there are very little air pockets.

Types of Glaciers

I never realised there was so many types of Glaciers, I was naive to think that ice was just ice but the only difference was it's geography. However when you learn that Glaciers cover around 10% of the world's land surface, which means that every continent in the world has a Glacier, and they contain between 70-80% of the worlds fresh water supplies it doesn't seem so surprising.
I have used information from mainly http://www.nsidc.org/ and the http://www.geography-site.co.uk/ to try and condense the vast amount of information there is to fairly simple terms. These will allow students and me alike to understand and remember what type of glaciers there are. I will also be using images as well, which will hopefully show us what they look like.

ICE SHEETS:-
Ice sheets are only found in the Antarctica and Greenland. These sheets are huge Continental masses of glacial ice and snow that are larger than 50000 square kilometres long and up to 4200 meters dense in some areas. As these sheets are so dense, they cover over the whole terrain with the exception of the trans antarctic mountains

Below I have attached illustrates of both Greenland Ice sheet and Antarctica Ice sheet using images from the NASA photo gallery http://www.nasa.gov/



Greenland and surrounding Ice Shelves



Antarctica and its Ice Shelves

 



ICE SHELVES:-
Ice shelves occur when Ice sheets past the land surface and further extend out over the sea and float on the water. These Ice shelves surround most of the antarctic continent, which can be shown in the above image of Antarctica. It is at this area of the Glacier where calving can take place, calving is where ice breaks off at the end of a Glacier. At the Ice Shelves, the sea weakens the Glacier and can cause massive bits of Ice to break off, fell into the ocean and cause Icebergs.

ICE CAPS:-
Ice caps are smaller versions of Ice sheets, covering areas that are smaller than 50000 square kilometres. They are more commonly formed in polar and sub-polar regions that are relatively flat and high altitude. Similar to Ice sheets, Ice caps will cover the land completely but at certain parts of the year some bedrock can be seen. Below is an image of Vatnajokull Glacier, which is Iceland's biggest Glacier and the second biggest in Europe. Underneath this 8100 square kilometre Ice cap Glacier is seven hidden volcanoes, which most are active.

Vatnajokull Glacier, Iceland
http://iceland.vefur.is/iceland_nature/glaciers_in_iceland/vatnajokull.htm

ICE FIELDS:-
Ice fields are similar to Ice caps, however ice fields are effected by the topography of the land below. An Ice field may span over many mountain peaks or even a mountain range. Below is an image of Kalstenius Ice field, located on Ellesmere Island, Canada,  The Ice field produces multiple glaciers that flow into a larger valley glacier. (Royal Canadian Air Force photograph at the World Data Center for Glaciology, Boulder)

Kalstenius Icefield,

VALLEY GLACIERS
Last but not least is Valley Glaciers. These glaciers originate from Ice fields or Ice caps that spill downhill. As you can see in the above picture of the Ice field, Valley glaciers look 'much like giant tongues'  (http://www.nsidc.org/) that usually flow down existing steep V- shape valleys that have been previously eroded from rivers etc. The sheer pressure of these glaciers cause the V-shape valleys to erode and enlarge into flat bottomed U-shape valleys. These valleys are a common sight around the world today from past Glaciation periods. Valley Glaciers can be very long and flow far enough to reach the sea, this is then known as a Tidewater Glacier. Tidewater Glaciers are responsible for calving small icebergs that are not as big as Icebergs from an Ice Shelves but can still cause problems.

Below is a Picture that I took of Franz Joseph Glacier in New Zealand, that hopefully illustrates a Valley Glacier being constraint by steep Valley walls. Also from the http://www.nsidc.org/ gallery is a image of a tidewater Glacier.








Lamplugh Glacier, Alaska
Tidewater Glacier, that shows pieces of Ice debris in the Water
http://www.nsidc.org/



Franz Joseph


There are many other types of Glaciers which can be found on http://www.nsidc.org/ and http://www.geography-site.co.uk/ however I felt that these were the most common and more important. Also this post would be a mile long if I added all types of Glaciers.

Task for Students

Each Student would be assigned a different type of Glacier, as homework or during lesson time they would research the particular glacier. They would then present the Glacier type to the class. This will encourage self learning as well as allowing students a chance to present in front of their classmates