You can have craggy peaks poking up through the middle of the ice, like this. There's an actual Eskimo name for them, they're called "Nunataks." The tallest Nunataks of the Juneau Icefield reach 2,500 meters.

This is still the Juneau Ice Field. This was taken about 9:00 p.m. The ice here is about 1,000 meters thick.

This is an aerial photo taken of the Norris Glacier. Clearly visible are all the crevasses which develop when a glacier changes direction or slope. It is about 2 km across this valley.

This is a valley glacier but the whole area is called an ice sheet. This is late May, and the glacier here is covered in snow. By the end of summer, the whole area would be open crevasses. This ice sheet feeds 40 to 50 glaciers many of which are 100 kilometers long themselves.

These bands are the rock rubble which has avalanched down the sides of these mountains and come to rest on the top of the glacier. This rubble is now being carried down glacier as the glacier moves. These bands are called moraines. When they are on the side of the glacier they are called lateral moraines.

Some of the crevasses are only centimeters wide while others are several meters wide. The deepest crevasses are in Antarctica and they are between 30 and 40 meters deep. In Alaska the deepest crevasses are probably less than 30 meters deep. Falling into a 5 meter crevasse could be fatal.

There were all sorts of rocks up to boulder size completely embedded in the ice. My flash reflecting off the ice prevented me from getting those in the photo.

One reason the water comes out like this is that fresh water is less dense than salt water so it rides on the surface of the ocean. The fresh water flows out over the salt water. You can often see the water flowing and it pushes all the ice bergs away.

It's very, very dangerous to go up close to the terminus of a glacier. Can you guess why? When ice bergs fall off the glacier or "calve" into the ocean, it's not so much that you're going to get hit by the ice berg that makes it dangerous, but when a big chunk of ice falls in the water, the huge wave generated could knock you over unless you're in a very, very big boat.

The silt is the result of the glacier scouring everything in its path as it goes through the valley and depositing large volumes of gravel & so on at its terminus. The silt is fine enough in particle size to be suspended in the water and it gives the ocean water in these fjords its pale green color. Also called "glacier flour."

This fjord also shows the pale green color of ocean water near tidewater glaciers.

This block of ice just sits in the ground and melts over the next 50 years or so, leaving a depression which fills with water. Glacier Bay was covered in ice until very recently, just over a 100 years ago, and the ice has recently receded.

Trees in Sitka grow right up to the high tide line. Sitka did not experience glaciation over these islands. This is shown in contrast to the next slide.

The land is actually rising at the small rate of about a centimeter or two per year but over 20 to 30 years that means the land has risen over a meter or more and the vegetation is catching up. So the trees don't grow right up to the high tide line but as the land is rising, the trees will begin to colonize more of that part of the land.

This photo, with a skier in the background for scale, shows that even though you see snow in front of you, that doesn't mean it's safe to walk across that snow. It may be a very thin covering over a crevasse. One can see, as summer progresses, that the snow bridge melts and exposes the crevasse.

Those tents are actually suspended over crevasses. This shows again that you cannot conclude how safe the ground is just by looking at whether there's snow visible or not.

Some of these streams can be quite wide and deep, and very dangerous to cross. On this particular glacier (not this particular stream) there's a river we couldn't jump across, we had to carefully wade across.

Gulkana Glacier showing a crevasse full of water.

If I jumped up into the air and landed into the moulin, a short second later I would hurdle straight down into the moulin and would disappear into darkness, pushed down into the glacier by the force of the ice cold water.

The Muldrow Glacier surged in 1957. That means the glacier suddenly moved very rapidly like 10-20 meters in a day as opposed to 100 meters in a year. This pothole is clearly draining out and is only 10 meters deep with water.

If one knows the rate at which a particular species of lichen grows, which of course is dependent on a number of things like temperature, rainfall, and so on, then you can look at the diameter of one of these circles and estimate the age of exposure of this boulder. This is one method used to date glacier advances and retreats.

This whole gray colored material in the photo is actually ice with just boulders on top. It's not moving any more and this is common in the front of glaciers that are kind of quiescent (quiet), i.e., not advancing or retreating, so this photo shows ice covered in boulders and rocks and stuff. The hole was probably the end of a moulin which used to have water pouring through it.

Any time you see a valley with this very nice u-shape to it, you can comfortably guess that it has been carved by a glacier. Rivers tend to give v-shapes to valleys whereas glaciers give u-shapes to valleys.

Typically, a bowl-shaped feature is left at the base of the mountain, like using an ice-cream scoop to scoop out a part of the mountain, which leaves a cirque. At the base of the cirque is a little lake, a very common feature with cirques, called a tarn. There are little fuzzy smudges in this image that were mosquitoes flying in front of the lens. This photo was taken in the Brooks Range, Alaska.