Landforms, Glaciers, and Erosion

We were lucky this year because we got to take the best Geology Field Trip ever—to the Canadian Rockies! We went to Banff and Jasper National Parks. It was amazing! You can read more about our trip here, but I'm including a few pictures of the mountains and glaciers we saw.

Below, you can read about a few activities we did to learn about these principles when we got back from our trip.

These glaciers were amazing to see! I love the blue tones of the ice as it gets thicker.

This is Athabasca Glacier—you can walk right up onto this one.

Gorgeous turquoise glacial lake

Perfect example of a glacial U-shaped valley!

One day we made play-dough (this is my favorite recipe) and the children made all the different kinds of landforms we'd been learning about: mountains, glaciers, moraines, volcanoes, and so forth.

A cave!

Fold mountain

A volcanic mountain range (from a hot spot). And I think there are some hoodoos in there too.

Teddy, very serious about his fold mountain…

and his sinkhole!

Fault-block and tectonic plate collision mountains

While in Canada, we stayed at a house by a river and found some beautiful river rocks.

They were already so smooth and flat and pretty! We collected a few…

And took them home to polish in our rock tumbler!

Didn't they turn out beautifully?

Another fun way to make landforms in with sand in a cake pan—then you pour water in to make deltas, rivers, lakes, etc. More pictures and ideas here.

Another activity we did was making some big blocks of ice and then experimenting with them on a nearby hill. We learned about glacial till, terminal and lateral moraines, cirques, glacial striations, etc. And, we had fun sliding down the hill on our ice blocks! :)

You can find more glacier activities here. And even more here.

Glacier Activities

We made "glaciers" by freezing layers of gravel and water in bread pans. Then we had fun doing various things with them—scraping them along different surfaces, letting them melt and observing what kind of features were left behind (till, moraines, etc.), and so forth. There are several good ideas for glacier-related activities here.

Maybe the most interesting thing we did, though, was demonstrate how glaciers melt and re-freeze as they move. One book we read said to think of them less as big ice bulldozers, and more as ice conveyor belts. The thawing and freezing of successive layers of glacier ice is an important part of why they move and shape the land the way they do.

This demonstration shows how pressure can force ice to melt (as it does on the bottom of a glacier) even when the temperature itself is not cold enough to cause melting. We set up a block of ice on top of two rulers between two stacks of books, and across the ice we hung a wire tied to two heavy stones. It was a very awkward, improvised set-up—you can see a much tidier example here.

As time passed, the pressure of the wire gradually melted the ice, and the wire began to cut through the ice block. As the children saw this, they predicted that eventually the ice would be cut into two pieces.

But the surprising thing is that the ice re-freezes above the wire as the pressure lessens on a particular place, leaving the wire inside the block of ice—and eventually, allowing the wire to cut all the way through the ice and still leave an intact ice block above it! Fascinating.

We should have gotten big ice-blocks from the store and slid down steep hills atop them, as I occasionally did with youth groups or for ward activities in college. But we didn't. Maybe next time!