January 24

Today is windy, cold and overcast. Winds are blowing out of the south off the Ross Ice Shelf at 25 to 30 kt. Temperatures are -8 to -10C (15F). Wind chill is -30C according the display. Waves are 3 to 4 ft, although they get bigger as we go farther north away from the ice. The forecast is for conditions to stay like this for the next day or so. It feels like Antarctica out there!

The heavy red line is the cruise track. 

The Ross Ice Shelf is to the east of McMurdo Station.

I have been on the boat for one month (since December 24). My world is pretty small--just the people on board and the focus on ocean sampling in this area. Two newspaper summaries arrive each day, but they both have mostly the same content. The difference between them is the fraction of space devoted to sports. The main stories have been the latest ups and downs of the Republican nomination campaign.

I have started putting out candy around 2 am as a moral booster for everyone. I have english toffee, hard candy and chocolate mints that I bought in Punta Arenas before we sailed. Even though there are fewer people up overnight, the candy seems to disappear in a few hours. I will keep putting it out until I run out. I have some M&Ms which I will put out soon as a special treat. I suspect that they won't last long.

We are now as far south as we will get, not quite 78S. We are traveling along the edge of the Ross Ice Shelf. Actually, we are a mile or two away so we are not too close just in case pieces of ice break off.

There is an interesting video on the ship of ice breaking off an ice shelf, creating a wave that washes over the stern of the Palmer (the ship we are on). Big chunks of ice ended up on the fantail and the deck was covered in several feet of water. It is very dramatic. Unfortunately it is too big to send home, but I have a copy for later viewing.

The Ross Ice Shelf is a dramatic feature. It is hard to get a sense of scale from the pictures (or even from the boat given the distance). The ice stretches from one horizon to the other.

The ice shelf is glacial ice, which is snow that has accumulted over a long time and compressed into ice. Antarctica is a dry place with snowfall of a few centimeters of water per year (an inch or two). An ice sheet has covered Antarctica for the last 30 million years or so; there has been plenty of time for a thick layer of ice to pile up.

Over time, the ice slides off Antarctica and floats in the ocean. The Ross Ice Shelf is the ocean end of an ice stream. You can impress your friends by using "marine terminus" as the ocean end of an ice stream.

At the marine terminus, the ice is 200 to 300 m (600 to 1000 ft) thick. Since about 10% of ice floats above the water surface, the ice is 60 to 100 ft high. It is about as high as the highest mast on this ship.

The ice shelf cracks for various reasons. Pieces of the ice shelf can break off, which is where icebergs come from.  This is how the glacier looses ice (it also melts at the bottom). The glacier is always sliding off the continent. The ocean edge of the ice shelf stays in the same place, more or less, because icebergs break off about as fast as the glacier slides of the land.