Amazing glacier

We’re back on the glacier. It’s time for summer skiing. We have been doing this for about ten years now.  In the beginning of the school's summer vacation we go skiing on a glacier.  It has become part of my duty as a ski dad, because my boys are addicted to snow (and I've posted about this before).

Actually, this year it’s only little boy and me. Older boy is running around on his own, with his buddies. This summer they have picked a different glacier. They’re driving down to the Alps, to spend 3-4 weeks on a glacier in Austria.  That’s OK with me, as long as he works to earn up the money himself.

Little boy and I made it simple. We went to the closest glacier, a four-hour drive from home, and we stay in the same camping down in the valley. We plan to ski four or five days, depending on the weather. So far it’s been shifty; partly sunny yesterday, snowy and foggy today, good forecasts for tomorrow.

Being on a glacier is quite amazing. We’re skiing on snow and ice that fell hundreds of years ago. Actually the surface is not that old. The snow we skied today fell last night.

Some years ago I bought a text book on glaciology, to learn about the science of glaciers.

The core of the glacier is old. When the snow is buried it gradually turns into ice that moves by plastic flow. The weight of the ice makes it flow from the top to the bottom, slowly, but steadily, a few meters per year. When pieces on the lower edge break off, the old bluish ice becomes visible.

Big glaciers are very useful for climate research, because glaciers keep a record of past climate.  The ice in the core contains small sealed air bubbles.  This allows scientists to measure for instance the CO2 levels of past times.

There are two main types of glaciers; polar (cold) glaciers and temperate (warm) glaciers.  Polar glaciers are found in the Antarctica and the Arctic (e.g. Greenland). They’re often frozen to the rock surface below. The glaciers on the American and Eurasian continents are mostly temperate.  They’re near the melting point, with free flowing water at the base.

In the upper part of the glacier, the accumulation of snow and ice is larger than the melting (and sublimation). In the lower part it’s opposite. The line of zero net accumulation (over a year) is called the firn line.

When glaciers flow over the terrain beneath, they’re squeezed and stretched such that crevasses are formed. Crevasses can be deep and dangerous. Therefore many glaciers are not suited for skiing.

The glacier where we’re skiing has a nice and smooth surface. There are just a few small crevasses near the top.  That’s the way it was last summer. This year I haven’t checked.

That’s one of the things that make glaciers so interesting. They’re changing all the time. Every summer there’s something different, if you have the curiosity and patience to look closely.

(Some pictures taken with my cell phone  at the glacier. (1) Skiing at the glacier. (2) A cool rock by the edge of the glacier. Great forces are needed to form a mountain range. This rock have experienced both metamorphosis and faulting . (3) At the lower part of the glacier the old bluish ice core is visible.)