Having decided upon glaciers as my topic of choice for this blog I have been keeping my eyes open for any relevant news articles or recent developments in the field. Luckily enough, I have found two such things!
Firstly would have to be the news that came through on the 19th of July about the Petermann Glacier in Greenland; an iceberg estimated to be the size of Manhattan broke away from the tongue of the glacier - a process known as calving. What makes this event so momentous is the fact that in 2010, another substantially big iceberg broke away from this same glacier. Scientists are worried by what has happened due to the size of the iceberg as well as its history. This news article shows how relevant this subject is and how it is constantly being updated with more information and developments being made frequently as more research is carried out.
At the bottom of the news article I found a very interesting interactive tool in which you put in your postcode and you can see how big the newly formed iceberg is in relation to where you live. From a teaching perspective this could engage the children with the subject; being able to see how big the iceberg is in relation to where they live could interest them and could help to show them the actual scale of what they are studying.
If you are interested, here is the link to the article (the interactive map is at the bottom!): 'Iceberg breaks off from Greenland's Petermann Glacier'
The second update I have found was actually through my University - Aberystwyth. Dr. Bethan Davies a research associate has just set up a new website entitled 'Antarctic Glaciers'. It is a brilliant new website with lots of information on glaciers which is easily accessible and easy to read. As Dr.Davies continues to do research, the website is updated on new information that is found out and lots of interesting things discovered during her research period. Not only this but there is also an 'Ask a Scientist' section in which, if you have any questions you can ask them and get them directly answered by somebody in the know! I think it could make a valuable resource as it is easy to use and provides a lot of answers!
If you would like to look at the website you can do so here: http://www.antarcticglaciers.org/
They are also on twitter with their updates @Antarcticglacie
Enjoy!
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Friday 20 July 2012
Wednesday 4 July 2012
Definition Galore
After my last post, I was left feeling slightly encouraged by the start I had made; sure, it hadn't been extensive on the knowledge front but it was a start. However, as I started to move on, looking at how glaciers form and the types of glacier I began to feel that I was missing something. As I continued to look through websites and diagrams I realised abruptly what it was that I felt I needed in this study; key terms. I therefore set about creating a table filled with terms that I felt would be important to contribute to my knowledge:
A lot of these words are quite long and complicated, especially words taken from the French and German language such as Bergschrund and Rouche Moutonee and so it may take a while for students (as well as myself) to fully get to grips with these terms. Showing students pictures alongside these definitions may also help with the learning of these terms as it is sometimes easier for students to be able to see and apply their knowledge rather than purely being told. After composing this table, I feel that I have furthered my knowledge purely by just understanding the key terms that I keep coming across. As well as this, I also felt that I may have even be halfway to composing a potential lesson resource! Handing out this table, or one somewhat similar, in lesson and getting students to either stick it in their book for reference or for an activity in which students would be handed the definitions and key terms separately and then asked to put the correct term and definition together. This could help to see how student have progressed with the topic as well as helping them further their own knowledge on the subject.
Finally, I also looked at how glaciers are formed. After trawling through many websites, images and youtube videos, I found that many of the diagrams were slightly misleading and confusing and so I went back to the National Snow and Ice Data Centre website which I felt gave the most succinct information that I needed. Essentially, glaciers form when snow remains in the same area every year and accumulates to the point where it eventually transforms into ice. As this process continues, the new snow that has accumulated buries and compresses the previous layers. This results in the snow re-crystallizing and becoming similar to grains of sugar. Over time, these grans become much larger in size and the air pockets between the grains becomes smaller causing an increase in density and eventually, over roughly two winters the snow turns into firn (refer to table above for definition). As the process of accumulation and compression occurs over many years, grain sizes become larger and larger and thus, a glacier is formed.
This, I feel, begins to explain not only how a glacier is formed but a few key terms which could be helpful for students to see how all these key terms fit together within the topic.
Overall, the creation of a key term table at the beginning of the topic could be helpful for pupils to refer back to throughout the learning of the subject as a helpful referencing guide as well as an aid for learning and revision. Creating activities around the table could also help to make lessons more interesting and engaging, assisted with pictures for an aided aid.
The next aim will be to look at the different types of glacier that can be found - something images will be very helpful for!
Websites used:
http://www.swisseduc.ch/glaciers/
http://nsidc.org/cryosphere/glaciers/questions/formed.html
http://www.geography-site.co.uk/pages/revision/ice.html
Key Term
|
Definition
|
Ablation
|
The process by which ice is lost from a glacial surface
through the processes of melting, sublimation or the calving of icebergs
|
Areal Scouring
|
The erosion of lowland
bedrock areas by an ice sheet (usually large scale)
|
Arête
|
A sharp ridge of rock
formed as a result of glacial erosion occurring from both sides
|
Basal Ice Layer
|
The layer of ice that is
found at the base of a glacier. It is strongly layered and can include a
variable amount of debris
|
Basal Sliding
|
The movement (sliding)
of a glacier over bedrock. This is often aided by the effect of meltwater
|
Bergschrund
|
A crevasse which forms
as a result of active glacier ice moving away from ice adhering to the
mountainside
|
Unstratified clay
deposited by a glacier and consisting of a variety of boulders. Often
referred to as 'till'
|
|
Cirque
|
An armchair shaped
hollow which has formed as a result of glacial erosion high on a mountain
side with steep sides and back wall. Also known as a 'corrie' or a 'cwm'
|
Crag-and-Tail
|
A glacially eroded rocky
hill. Produced as ice moved over a hard layer of rock which protected softer
rock behind it. This formed an outcrop with a steep side facing ice flow and
a gentle slope on the down stream side
|
Crevasse
|
Vertical crack in the
glacial ice. May be formed as a result of the glacier making a sharp turn or
moving over undulations in the glacier bed. Can vary in size and depth
|
Drumlin
|
Elongated, oval hill
composed of glacial debris. The long axis runs parallel to the flow of the
original glacier with the steeper end facing in the direction of the ice
flow.
|
Englacial Conduit
|
A channel formed within
the glacier which carries waters towards the glacier bed or margins
|
Erratic
|
Boulders, or large
blocks of bedrock that has been, or is being, transported away from its
source by a glacier and deposited when the ice melts
|
Esker
|
A long, narrow ride of
sand and gravel deposited by a stream in a subglacial tunnel
|
Firn
|
Dense old snow (in
between the stages of snow and glacial ice) that has a sugary texture and in
which the crystals are partly joined together
|
A tributary valley with
the floor at a higher relief than the main channel into which it flows. Often
marked by a waterfall
|
|
Ice Sheet
|
A large mass of snow and
ice of a considerable thickness and covers an area of more than 50,000km²
|
Little Ice Age
|
Period of time which led
to the expansion of valley and cirque glaciers world wide. Maximum extent
occurring in 1700-1850 AD in many temperate regions
|
Moraine
|
Distinct ridges and
mounds of debris laid down by a glacier or pushed up by it. Many different
types
|
Lateral Moraine
|
Debris deposited along
the side of a glacier
|
Medial Moraine
|
Band of debris along the
centre of a glacier where two streams of ice merge
|
Terminal Moraine
|
Ridge running across a
valley which represents the maximum advance of a glacier
|
Ground Moraine
|
Debris deposited on
valley floor. Found where glacial ice meets rock at the bottom of the glacier
|
Push Moraine
|
Assortment of debris
that has been pushed up by a glacier during an advance. Can range from a few
metres to tens of metres in height.
|
Moulin
|
Roughly circular, almost
vertical hole within the glacier through which water can enter from the
surface down the glacier bed
|
Outwash plain
|
Spread of debris
deposited by meltwater streams coming from a glacier
|
Roche Moutonée
|
Rocky hillock with a
gently inclined, smooth up-valley facing slope and a steep, rough down-valley
facing slope
|
Striations
|
Scratch marks found on
rocks as a result of the abrasive effect of debris rich ice sliding over
bedrock
|
Small lake occupying a
hollow eroded by ice; common in cirques
|
|
Truncated Spur
|
River spur that has been
cut off by glaciation of a former river valley. Characterised by a very steep
cliff
|
A lot of these words are quite long and complicated, especially words taken from the French and German language such as Bergschrund and Rouche Moutonee and so it may take a while for students (as well as myself) to fully get to grips with these terms. Showing students pictures alongside these definitions may also help with the learning of these terms as it is sometimes easier for students to be able to see and apply their knowledge rather than purely being told. After composing this table, I feel that I have furthered my knowledge purely by just understanding the key terms that I keep coming across. As well as this, I also felt that I may have even be halfway to composing a potential lesson resource! Handing out this table, or one somewhat similar, in lesson and getting students to either stick it in their book for reference or for an activity in which students would be handed the definitions and key terms separately and then asked to put the correct term and definition together. This could help to see how student have progressed with the topic as well as helping them further their own knowledge on the subject.
Finally, I also looked at how glaciers are formed. After trawling through many websites, images and youtube videos, I found that many of the diagrams were slightly misleading and confusing and so I went back to the National Snow and Ice Data Centre website which I felt gave the most succinct information that I needed. Essentially, glaciers form when snow remains in the same area every year and accumulates to the point where it eventually transforms into ice. As this process continues, the new snow that has accumulated buries and compresses the previous layers. This results in the snow re-crystallizing and becoming similar to grains of sugar. Over time, these grans become much larger in size and the air pockets between the grains becomes smaller causing an increase in density and eventually, over roughly two winters the snow turns into firn (refer to table above for definition). As the process of accumulation and compression occurs over many years, grain sizes become larger and larger and thus, a glacier is formed.
This, I feel, begins to explain not only how a glacier is formed but a few key terms which could be helpful for students to see how all these key terms fit together within the topic.
Overall, the creation of a key term table at the beginning of the topic could be helpful for pupils to refer back to throughout the learning of the subject as a helpful referencing guide as well as an aid for learning and revision. Creating activities around the table could also help to make lessons more interesting and engaging, assisted with pictures for an aided aid.
The next aim will be to look at the different types of glacier that can be found - something images will be very helpful for!
Websites used:
http://www.swisseduc.ch/glaciers/
http://nsidc.org/cryosphere/glaciers/questions/formed.html
http://www.geography-site.co.uk/pages/revision/ice.html
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