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4 November, 1996Today I took a shower, it was the first one in three days. I don't dislike bathing but water is a precious resource at McMurdo and its use, except for drinking, is regulated. We are limited to one two-minute shower every other day. That doesn't seem to make sense on a continent that has 90% of the earth's fresh water and is surrounded by an endless supply of seawater. I remember one of my students stating they could just melt the ice or distill the seawater for our fresh water needs. The problem here isn't the lack of water, it's the lack of fuel to convert the water to a useful form. Once a year an icebreaker clears a path through the sea ice so a tanker can bring in a supply of fuel. McMurdo can produce 80,000 gallons of fresh water a day. I wondered how much fuel it would take to distill that amount of seawater. After looking up the heat of combustion of diesel fuel, the specific heat and heat of vaporization of water, and then doing a few calculations, I estimated 7,200 gallons! I knew it would take less to melt ice because the heat of fusion of water is about one-seventh the heat of vaporization. Another calculation yielded about 1200 gallons to melt enough ice for a one-day supply of water. Neither of these methods seemed possible with the fuel resources here. By chance, Jim met the power plant foreman and asked how much fuel was actually used to desalinate the daily water supply. The reply was 100 gallons. The process uses a reverse osmosis pump. Seawater is pumped through a filter that passes the water but retains the salts. Fresh water without melting or evaporating! Here, things we would take for granted at home are a major effort of time and resources. Today Andrea, an ASA General Assistant, helped with dive tending. She has a degree in anthropology and is spending four months on the ice. Most people seem to be overqualified for their work, however, every job is essential and must be done competently and efficiently. Dom Tedeschi tedeschid@earthlink.net
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