Antarctic crew faces stiff winds, short days
By JOSEPH TORRES
© St. Petersburg Times, published May 16, 2001
MARGUERITE BAY, Antarctica -- A busy two weeks.
Our University of South Florida group has a lot of sampling to do to meet our goals for the cruise. Also, I am "chief scientist," which means that I act as a liaison between the scientists, the crew of the vessel, and our support staff from the Antarctic program.
I make up the day's schedule, deciding where the boat will go, making sure that all the scientists on board get the opportunity to complete their projects, and writing reports on our activities.
Our first week, we sampled for krill and fish in the open ocean to the west of the Antarctic Peninsula. We were at the edge of the continental shelf, which is the shallow part of the ocean bottom that joins the continent.
Think of it as an extension of the shoreline that extends as a submerged shallow region for several miles until it finally drops off to the great depths (12,000 feet) typical of the open ocean.
The Antarctic Peninsula, like Florida, has a wide continental shelf. Florida's is about 200 miles wide. The shelf here is a little more than 100 miles. But the peninsula's shelf is much deeper, about 1,000 feet or so.
Why so deep? Because the weight of all the ice on the Antarctic continent pushes it (and its shelf) downward so that its continental shelf regions are much deeper than in the rest of the world.
The weather was unkind during our open-ocean sampling. Winds consistently blew 25 to 35 mph. Seas were 15 to 20 feet.
Air temperatures have been remarkably warm: between 32 and 38 degrees Fahrenheit, or as much as 17 degrees above average for May.
As we get closer to winter, the days are getting shorter. We are below the Antarctic Circle at a latitude of about 68 degrees.
Before the end of the cruise, we'll have a few days when the sun never rises above the horizon. Right now, we have good daylight between 10 a.m. and 3 p.m. It's pitch dark at 5 p.m.
After finishing our sampling in the rough ocean, we moved into our main study area, the northeast corner of Marguerite Bay, about halfway down the Antarctic Peninsula.
We think it's an important overwintering area for krill. Many Adelie penguins are believed to spend the winter here, and their favorite food is krill.
With the days getting shorter and Adelies being visual predators who need light to hunt and survive, it's easy to see why we figured Marguerite Bay would be an important winter habitat for krill. The penguins pointed it out to us.
Our sampling with nets suggests that the penguins are right.
There is plenty of penguin (and seal) food around, but few penguins or seals, probably because there is no sea ice yet. They need a place to "haul out."
We are now heading to the southeast corner of Marguerite Bay in quest of krill, penguins, seals and ice. The winds remain stiff -- more than 40 knots out of the north all day long.
To learn more
Dr. Torres' mission is featured on the National Geographic Web site: http://www.nationalgeographic.com/sealab/antarctica.
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