23 February, 2001

How sea ice is formed

-06 14 lat/ 094 15 long

We were making our transit west, working along the Antarctic coastline and racing to recapture time lost waiting out the storm. Our goals are high, there is so much to accomplish and so many unknowns in the sites we are aim for. Who knows what treasures the ocean will reveal. On one of my daily walks on deck I noticed pancake ice on the sea's surface. I have heard pancake ice, but have never seen it. I was transfixed as the ship glided through water laid out end to end with these Antarctic "water lilies". As the ship passed through, the pancakes slid over each other like scales on a snake. Its' sound clinking in the ship's wake, creating its own harmonic resonance. Pancake ice is the first sign winter of winter coming. It forms when the temperature is cold enough to freeze the ocean surface. Water molecules freeze together to form precise patterns, like a tile floor, whilst squeezing out the salt ions and holding on to air parcticles. As a result, dense, salt-rich water is forced underneath the freezing sea surface and sinks to the ocean floor (revisit story about fingerprints on the CTD entry).