Hello and welcome to my presentation about all things ice today we are going back 2.4 million years and learning all about glaciers and the ice age.
Here on slide 1, we have 5 images the first a 2 answer the question what are glaciers there is a diagram with all the glacial terms and a good view of what the glacier looks like from all sides and a photo to show you what a real-life glacier looks like. The next picture is a detailed map of the glacial areas around the world and how they are melting it is called where has all the ice gone. The final 2 images show the ice covering as it is now and how it was in the ice age. Would you have been feeling the cold where you live?
On this slide we are covering the speed that glaciers travel. Really this depends on several variants for instance a glacier will move faster going down a hill than on the straight to gradient is a variable, also the weight the heat of the glacier play a part in its speed. Also mentioned on the slide is some ice features that you might have seen in the ice age a number 1 is a crevasse which is like a big crack in the ice it can be very dangerous for mountain climbers as you can fall down them and get hurt or even die. number 2 is an ice shelf which is when a big block of frozen water begins to melt at the bottom leaving a shelf of ice on the top. Number 3 is a mountain glacier, number 4 is an ice sheet which is when the surface of the ice freezes and turns water into solid ground when the weather is cold ice sheets are a favoured hunting place of the seal and polar bear. The 5th and final picture is of an iceberg which is like a big piece of floating ice on the surface of the sea. These glacial features did not completely vanish after the ice age if you go to really cold or mountainous areas such as the artic or the alps you can still see them.
In this slide we use diagrams to explain the formation of glacial features first the formation of a corrie now when you look at a where a corrie once was all you will see is a lake but once it would have been completely frozen you see when snow builds up in a small hollow and is unable to move or melt then eventually as more snow falls upon it the pressure compacts it until it becomes ice. As time goes on then moraine and ice rotation begin to make the wall of the corrie steeped and the bowl deeper. At the end of the ice age the ice melts leaving a corrie lake or tarn behind. The second diagram shows the formation of a pyramidal peak and an Arête, an Arête is made when 2 or more corries are on the same mountain as shown in the illustration both sides of the rock become sloped making a sharp peak. They can also form when 2 u shaped valleys are formed next to each other. A pyramidal peak is formed when 3 Arêtes meet at the top of a mountain making a peak like that of a pyramid.
On this slide we are going to look at pictures of corries, Arêtes and pyramidal peaks and a tarn for good measure. The first picture is of a corrie, Arête and pyramidal peak and it is shown to you on the picture which ones are which. There is also a picture of each individual thing but as you may have learned pyramidal peaks do not come alone so you may be able to spot all 3 in the pyramidal peak picture.
On this slide you will see 3 features made by glaciers that you can see today. The first is a ribbon lake which is lake but to any old lake it is made in a very funny shape it is shaped like a finger it is made when a glacier cuts through a length of soft rock but struggles to cut through the hard rock inclosing it this leads to a dead end forming, eventually the mouth of the dead end will be dammed, and a lake will form. There is also a u-shaped valley which is the valley a glacier makes on it’s journey. The final thing is a hanging valley which is when 2 glaciers meet and join together but now it is basically just a waterfall
On this slide you will see 3 other types of feature we can see today the first one is my particular favourite these giant rocks are called erratics and they have been transported 100s even 1000s of miles inside glaciers and dropped of at random places around the world. The next selection of pictures is of drumlins which are formed when