Day 29-32 of 68 – Antarctica – Part 4 Ice

February 7, 2018 Paul Groves

Obviously, when you think of the Antarctic, you visualize ice. The Antarctic is the driest place on earth. This was difficult for me to grasp at first, since there is a lot of ice and snow. The truth is that it DOES snow here a little each year (very little) but since that snow does not melt, the snow accumulates and compresses. This compression results in the blue color. Highly compressed ice scatters the longer wavelengths of light (the red end of the spectrum) and transmits the shorter wavelengths (the blues). The beautiful blue color of the ice floats and icebergs comes from this scattering of light, but the snow and ice that we see can be thousands of years old.

One morning we opened the curtains at 6:00 a.m. and our entire window view was taken up with an iceberg that measured 120 feet tall! Here are two views of this iceberg. I wish there had been something nearby that would demonstrate the scale of this huge chunk of ice.

We saw several seals and penguins who jumped onto the ice floats to rest between feedings. As the salt water cools and freezes, the ice formed is less salty and the liquid water becomes more salty and sinks. This causes the nutrient-rich water below to be pushed to the surface. This is why we find animals in the areas with the sea ice forming. This is a picture that Ron captured of a Crabeater Seal on an ice float.

We never got tired of watching the beautiful shapes and variety of icebergs. It is also interesting to remember that 90% of the iceberg is hidden from view below the water. The one huge flat expanse of ice that four football fields could be placed on it. The ice below the water level that we cannot see sometimes hits the bottom of the ocean and the iceberg stays in one place. Other large icebergs are plotted with GPS and added to the navigational charts.