Ryan: I'm getting dizzy. What are we looking at?

Morgan: Looks like winter on the wide open tundra to me.

Morgan: Wait a minute...We're in the mountains!

Ryan: And what mountains they are! Have you taken us to the Himalayas or something?

Inukshuk: These mountains are big all right, but not quite that big. You are looking at the St. Elias Range in the southwest Yukon, home to Canada's highest mountain - Mt. Logan - and some of the most spectacular alpine scenery on earth.

Ryan: I don't think I've ever seen so much snow! It must have been piling up for an awfully long time.

Inukshuk: Mt. Logan acts like a giant catcher's mitt for snow, forcing wet winds from the Pacific to drop their moisture load. Because it's so high, most of the snow that falls here never melts in summer.

Morgan: So how long has it been piling up?

Inukshuk: Well, for several thousand years actually.

Morgan: You don't mean...since the last ice age?

Inukshuk: My friend, it still is the ice age up here. As all that snow piles up over many years, it gradually compresses into glacial ice. You are looking at the biggest icefield in North America.

Ryan: So, how thick can these glaciers get?

Inukshuk: No one knows for sure. Perhaps a half of a kilometre in places.  Maybe more.  It would be quite a job drilling through all that ice - not that people haven't tried that of course!

Ryan: Why would anyone bother drilling holes in monster glaciers like these?

Inukshuk: Oh, they're full of treasures.

Morgan: Oh...so they're trying to find gold and diamonds - that sort of thing - under the ice?

Inukshuk: Not under the ice. In it.

Ryan: What the...? Who cares about glacial ice?

Inukshuk: Scientists studying past climates certainly do. They regard these glaciers at the top of Canada as priceless storehouses of information, crammed with secrets about the weather patterns that brought snow to these mountains so long ago. By drilling into the ice, they are truly drilling through time. They extract long cores of ice full of clues about conditions in our ancient atmosphere. How dusty was it? What chemicals were floating in the air? When were nearby volcanoes active? When do human pollutants show up? What was the temperature back then? These are the kinds of questions...

Morgan: (interrupting) Wait a minute. How could you possibly measure air temperature from ice that formed a thousand years ago?

Inukshuk: Good question. Though the original snowflakes were obliterated long ago, the ice layer created by them still carries information about climate conditions when they fell from the sky. One key to unlocking this clue is found in different forms, or isotopes, of oxygen and hydrogen.

Ryan: Huh?

Inukshuk: Everyone knows that water is made up of hydrogen and oxygen.

Ryan: Well, sure.

Inukshuk: Ah, but did you know that all water is not created equal? Hydrogen and oxygen exist in many different forms, or isotopes. A total of nine different kinds of water molecules can form from these isotopes depending on atmospheric conditions - including temperature. As these researchers study different layers in the ice core, changing mixtures in this frozen isotope soup can tell them a lot about changing climate conditions through time. These differences can even hint at where the original moisture came from. For instance, it might have blown in from as far away as Hawaii, or beyond!

Morgan: You can tell all that from a few slices of ice?

Inukshuk: Uh-huh.

Morgan: I'm pretty good at reading snow like a book. You know, navigating by the shape of snowdrifts, figuring out what animals have trotted by, or finding the best snow to build an igloo. That's common knowledge where I live. But I couldn't tell one chunk of glacial ice from another!

Inukshuk: You're fortunate in being able to read snow so easily. Reading the clues locked in glacial ice cores is a lot trickier and can take many months of intense laboratory work.

Ryan: Not to mention all the work of climbing this huge mountain, drilling through a rock-hard glacier, and hauling the ice core back to the lab without busting or melting it - now that's what I call work!

Inukshuk: You're right. It's no picnic working up here. Especially when a thumping good snowstorm traps you in a tent for several days at a stretch. But for these researchers, it's worth it. The wealth of information unlocked by their ice cores would fill many books about past climates and our role in changing them.

Ryan: Oh-oh. Looks like a snowstorm is brewing. Shouldn't we run for cover?

Morgan: (cool as a cucumber) Hey, it's just another snowy page in a very long storybook.... But...now that you mention it...I'm with you! Head for those tents!!

Image Sources: