Inside the Ross Ice Shelf, Antarctica

Near White Island - at 78 degrees South - the Ross Ice Shelf is several hundred meters thick. As it is moved northwards by the constant push of giant glaciers descending from the polar plateau, it is grounded near White Island, and splits open into huge rifts. These rifts start at a width of merely a few centimeters, and gradually widen to 100 meters or more. At the narrow end, they are covered by a snow-bridge and are nearly invisible. As a result, they can be quite treacherous, as some covered portions of the cracks are large enough to swallow tracked vehicles. The bottom of these rifts is made up of frozen saltwater from the Ross Sea. The interior of the rifts is frequently supercooled to forty degrees below freezing or even lower. Along the sides of the giant crevasses, ash deposits from ancient eruptions of the volcanos on nearby Ross Island - Mt. Erebus, Mt. Terra Nova and Mt. Terror - can be seen as dark horizontal bands.

Here are some images taken inside West Rift, near White Island, in 1981.

Before we discovered these rifts, we were already familiar with unusual ice formations in and around McMurdo Sound. The scaling of objects is really hard to determine down south, even more so from images. Even in real life, the air is so clear and ice structures are so strange, that it is very difficult to say how big things really are. In the image on the left, we are looking at a very small crack in an ice-bubble near our camp. The crack is perhaps 45 cm deep, and 30 cm wide. The ice "bubble" was maybe 1 meter tall.

On the right is another image taken in a similar bubble crack. The "horse-head" type sculpture is only about 15 cm tall.

We had also inspected ice caves located near Scott Base, a New Zealand research station on Ross Island, during our survival training.

Now, let's descend into the Ross Ice Shelf:

We found West Rift quite by accident (no need to go into details here), this is what it appeared like from the top.

On one end the snow-bridge had previously collapsed, and provided an easy means of descent, after digging a hole through the present snowbridge. The rope on the left of this picture is leading back to the entry hole near the top.

We are entering another world now. It hardly is believeable that we are in fact still on the same planet. This is a cathedral of ice.

Huge sections of the side walls have peeled off under the immense pressure of the moving ice shelf. Big chunks have also fallen down from the snow bridge. We can stand on the frozen floor - although it is very slick. Crampons are handy in here.

Since the snowbridges tend to collapse every now and then, snow blows into the inside during blizzards. This gives everything a powdered coating of frosty snow and ice.

Every now and then we can hear slight popping and cracking sounds as the ice moves slowly. During the winter of 1981, we conducted a survey of the ice movement, and determined that West Rift moved northward between 100 and 250 meters per year, depending on how close to White Island we measured.

Near the closing end of the rift the crevasse became small enough to touch both shoulders at the same time. This image is looking straight up at the snow bridge, which is quite thin here.

Deep, deep inside cracks, crevasses and ice caves, all but the shortes wavelengths are filtered out by the frozen water. All we can see is blue. The hues are so delicate, and the blues so deep, one could once again easily imagine to be on another planet!

The Great White South

Antarctic Wild Life

Getting chilled? Warm up inside an erupting volcano in:
The Ring of Fire

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