Did you know that glaciers hold nearly 2% of Earth's water? Created by MIT+K12.
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- What's the difference between a glacier and ice caps?(5 votes)
- Ice caps - large bodies of more or less stagnant ice at the earth's poles
Glaciers - ice that is moving (flowing)
So an ice cap is a non moving ice form usually at the poles, and the key distinction to define a glacier is that it has to be moving. If a glacier were to stop moving (flowing) then it would be called an ice sheet or an ice field.(12 votes)
- Great video! I've heard that the large glaciers somewhere north are melting, but this video doesn't go over that. When the glaciers melt, do large icebergs break off from the glacier or small ones?(8 votes)
- A glacier still does need an incline to move, doesn't it? Uniform pressure won't produce a net force, right?(5 votes)
- Yes, but unlike us pushing an icecube , nothing will 'push' the glacier. All the causes need to be natural.(3 votes)
- What's the difference between glaciers and icebergs(2 votes)
- Glaciers are made up of fallen snow that, over many years, compresses into large, thickened ice masses. Glaciers form when snow remains in one location long enough to transform into ice. What makes glaciers unique is their ability to move. Due to sheer mass, glaciers flow like very slow rivers. Some glaciers are as small as football fields, while others grow to be dozens or even hundreds of kilometers long. An iceberg is a large piece of freshwater ice that has broken off a glacier or an ice shelf and is floating freely in open water.(2 votes)
- what form was the chocolate when they put it on there?(2 votes)
- I still don't get how glaciers move rocks.Also,what is a glacier?(1 vote)
- a glacier is a large chunk of ice that slowly slides across the land, dragging rocks and soil along with it. (glaciers formed the great lakes, by the way)(2 votes)
- At 5.31, was it the pressure of all that chocolate build up that caused the bottom of the glacier to almost co-laps?(1 vote)
(machine sounds) (wind blowing) (waves crashing) - You know, science can be pretty hard work sometimes. But nature does a lot of work too. Today we're here at Cape Cod to talk about one of nature's coolest workers, glaciers. What makes glaciers so cool? Well, you might know how water can move rocks and stones around, you know, small ones like this one. But glaciers can move things that are much, much bigger. How much bigger? Well, how about this? Or this? Or this? That's right, even really big rocks like this one, can be moved by glaciers. I guess this would be pretty tough to move by myself, huh? (groans) That all begs the question, what is a glacier? Well, a glacier is a large, permanent body of ice that forms when snow falls in the winter but doesn't melt in the summer. (machine crushing ice) Over time that ice can build up, forming a glacier. In fact, it can turn out to be quite a lot. Glaciers hold nearly 2% of the Earth's water, which is nearly 200 times the amount held in rivers, lakes, and streams combined. When this ice meets the ocean it can break off, forming icebergs. Which is a big problem if you happen to have a ship. Titanic, anybody? Ahh. But, does ice move? Well, different materials flow at different rates and under different conditions. Some materials, like this milk, flow quickly. Other materials, like this maple syrup, or this chocolate pudding, flow more slowly. Some materials, like this banana, don't seem to flow at all, that is, unless you put them under enough stress or pressure to make them move. Ice slides, but with enough pressure it would flow too. Unfortunately, it's a little difficult to get that much pressure here. But we can demonstrate some of the same processes using chocolate. Here, we've made a model glacier out of chocolate. We've used cookie crumbs to represent rocks on the bottom of the glacier, and shaved chocolate to represent snow and ice. We used chocolate because it is soft enough to move even under low pressures like this. In this experiment we added chocolate to the top of the glacier every 12 minutes. Once enough chocolate is added, the glacier really gets going. If you look closely, you can even see crevasses, or cracks, where the top of glacier broke apart. We did this experiment for six hours, but you can do a shorter experiment by using pudding. Now we're ready to open our chocolate glacier. One of the things to notice is that the pieces down at the bottom are much more solid than the pieces up at the top. This is because the chocolate transformed on its way down the glacier, just like snow transforms into ice. Another thing to notice is that the pieces of cookie crumb stuck on the bottom of the chocolate. Glaciers trap rocks on the bottom of the ice and drag it along as the glacier moves. You'll see even though the cookie crumbs were different sizes, many of them got stuck on the bottom of the chocolate. So, glaciers drag along different sizes of rocks as they move. Perhaps you can see rocks and sand trapped in a real glacier, like on the left. Or, you can see the same process happening on a smaller scale, on the right. That's a snow bank melting in the parking lot. And because ice, unlike water, doesn't sort rocks by size, glacial deposits have all different types of rocks, of all different sizes, all in the same place. So the next time you see a bunch of big rocks surrounded by smaller rocks, you should ask yourself, "Could this have been caused by a glacier?" The answer could be yes. Or not.