Thread by @celestelabedz

Know a kid who would rather watch #Frozen2 on repeat than do schoolwork?

Well then, buckle up right here for a kid-friendly, activity-filled, Frozen-themed science lesson thread from me, glaciologist Elsa the #SciencePrincess! ❄️👸👩‍🔬

First off, let’s get our Frozen on! Watch the video for Show Yourself, and sing along if you want! 🎶 This is when Elsa goes to a glacier, so this is where we’ll look for some science:

This song calls the glacier “a river full of memory”, a line from the lullaby Elsa and Anna’s mother sang. Real glaciers are rivers full of memory, too! To see why, let’s learn what a glacier is and how they form...

ACTIVITY: Search “glacier” on Google Images and explore the pictures of these huge piles of ice. What colors are they? How big are they? What kind of places are they in? Do any of them look like the glacier Elsa goes to?

Glaciers form where more snow falls in the winter than can melt in summer. That usually happens at very high places (like the tops of tall mountains) or at places near the north or south poles, where it’s very cold. 🌨️🥶

Snow falls onto a glacier each year. The weight of the new snow squishes down the snow below, compressing it into solid ice.
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Imagine (or try!) taking a handful of shredded cheese “snow” and smushing it as tight as you can. Solid cheese!

In addition to squishing the snow into ice, the heavy weight also pushes the glacier to ooze downhill (activity coming up on this). It may seem odd that hard ice can flow, but that’s what millions of pounds of weight can do!

As the ice flows, it can reach somewhere where snow isn’t building up any more, because it’s too hot or dry. 🌡️ Here, the ice can break or melt, just like if you left an ice cube somewhere too warm. Sometimes glaciers end on land, and sometimes they end in water.

ACTIVITY: Make some slime (Google for a recipe) and put it in a “valley” made of a bread pan or a cut cereal box. Tilt the “valley” and watch the slime flow under its own weight, just like a glacier! Here’s a great slime glacier from @GlacialGeomorph:

https://twitter.com/GlacialGeomorph/status/1118237152817455104

That flow is what makes a glacier a “river” of ice! They move in winding paths through valleys, similar to rivers. Take a look at this river and this glacier from above. How are they similar? How are they different?

So that covers the “river” part of the “river full of memory” line! 🎶 Now we can explore the “memory” part.

Since glaciers are made of snow building up year after year, they end up with layers. Each layer is made of snow from one year, and they’re stacked in order from oldest at the bottom to youngest at the top.
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Big glaciers can have thousands of layers. Since each layer is a year, a glacier is like a scrapbook! 📖 Scientists drill cores (long cylinders of ice) to get a little bit of each layer. The chemistry of each layer’s snow gives information about the environment that year.

ACTIVITY: Put a layer of brown sugar in a cup, then add a layer of white sugar on top. Add a few more alternating layers, then plunge a clear drinking straw into it. Seal the top of the straw with your finger, then pull up the “core”. 🥤 What do you see?

The song is right: a glacier IS a river full of memory! The memories Elsa found and the memories scientists look for are a little different, but it’s the same cool idea of finding the past in ice! 🕑

Another cool part of the song is when Elsa is running through the tunnel in the glacier, eventually reaching a cave. This looks magical, but it’s actually more realistic than you might think!

Many glaciers have tunnels and caves inside because of flowing water. 🌊 Ice at the surface can melt and fall into holes called moulins, where it enters the inside of the glacier. The water goes through the inside of the ice until it reaches the bottom and flows out the end.

ACTIVITY: Explore this 360˚ video of a real ice cave in Alaska from @okaytobesmart. Click and drag around to see what flowing water can make! What do you see? What do you hear? How is it similar to the one Elsa went in? How is it different?

Now you’ve learned a few facts about glaciers that can make Frozen even cooler next time you watch it! ❄️👸👩‍🔬

Review questions for eager learners:

Where in the world can you find glaciers?
What makes a glacier flow?
Where is the oldest ice in a glacier?
What makes caves in glaciers?

BONUS CHALLENGE: Frozen takes place in Norway, and the glacier where Elsa goes is across the sea to the north. Find Norway on Google Earth or Google Maps and start exploring. Where could Elsa’s glacier be? 🌍

Can’t get enough glaciers? I’m happy to answer some questions in the replies, and here’s a few kid-friendly sites about ice from @NASA to explore:
- climatekids.nasa.gov/10-things-glac…
- earthobservatory.nasa.gov/blogs/eokids/g…
- icesat-2.gsfc.nasa.gov/fun_zone