Ice Caves...

I finally got to go on the ice cave tour yesterday, and it was absolutely amazing - definitely the highlight of my trip so far. The ice caves are located at the Mount Erebus Glacier Ice Tongue, about 7 miles north of McMurdo Station. The ice tongue is part of the Erebus glacier that comes off of Ross Island and floats on the water. The sea water remains frozen most of the year (and really cold the rest) so unlike other glaciers, when it reaches the water, it does not break off and make icebergs very readily. Also, the area is protected by 2 peninsulas so this keeps large wave away after the ice melts, which also helps prevent iceberg formation. So what results is about a 5 mile long 50 foot high glacier sticking out from the island.

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All along the edge of the glacier there are ice caves. Many are unstable and could collapse at any time as the glacier moves, but there are a couple you can go into safely. The one I went into had an opening about the size a manhole cover, then you slid down an ice chute about 20 feet to where it opened up into a much larger opening. The whole cave was probably about 100 feet deep, and the main room was probably about the size of a 2-car garage. There were many very cool stalactite like formation made of ice crystals, and the whole place glowed blue from the light passing through the ice. It was very neat. At one point the guide had everyone be quiet for a few minutes and you could actually hear the ice moving around you as the glacier creeps slowly along.

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Because the glacier is floating on the water of the ocean, there are of course tides. The water of the ocean goes up and down and liquid water from below is actually forced up through cracks in the ice as the tide changes. This creates pools of water in front of the glacier which of course quickly freeze into light blue ponds of almost perfectly clear ice near the caves. It is really a neat experience that I will not soon forget. Below are just a few of the many pictures I took.

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The edge of the glacier with a collection pool below it. It was very gloomy outside, so the blue of the pools didn't quite come out as well as I would have hoped.

Another view of the edge of the glacier with a pool at the base.

The chute entrance to the cave with a guy I work with already at the bottom.

Ice crystal "stalactites"

A view through the cave to another entrance

Inside the main room of the cave - that is actually the color it was in there.

A view along the side of the glacier.