TITLE:  Ice in Excess 
AUTHORS: Kristan Hutchison, Sun Staff
DATE: 2Nov01 
PLACE: The Antarctic Sun
THEME: News on the Ice 
URL: http://www.polar.org/AntSun/2001_1028/index.html

TEXT: 
Sea ice is a fickle thing. Sometimes there's too little. This year 
there's too much off the Antarctic Peninsula and in McMurdo Sound.
Icebergs large enough to be small states are partially blocking the 
flow of water to McMurdo Sound, holding the sea ice solid.  One of 
the bergs, B-15A, extends about 1,000 feet down, blocking the currents 
of water that usually circulate through McMurdo Sound and help move
the sea ice out.  "It's turned this whole area into a mill pond," 
said Ted Dettmar, lead instructor at Field Safety Training Program.
Many years winter storms blow out the sea ice, leaving open water in 
July, Dettmar said. By the time the Coast Guard ice breakers arrive 
in December the ice edge is typically 15 to 20 miles (24 to 32 kilometers) 
away from McMurdo Station.

This year people wintering at McMurdo Station never saw open water,
Dettmar said. The sea ice is now 9½ feet (3 meters) thick in front of 
McMurdo, and 10 to 14½ feet (3 to 4.4 meters) thick at the runway. The 
sea ice extends past Cape Byrd and Dettmar expects the ice breaker may 
have to cut through more than 80 miles (129 kilometers) off ice to reach 
McMurdo.  The Coast Guard has also been keeping tabs on the ice edge 
situation. The Polar Star is coming out of drydock and is scheduled to 
start breaking a channel to McMurdo on Dec. 28. The ice could change 
dramatically by then, said U.S. Coast Guard Lt. April Brown. Or not.
"Of course we are researching contingency plans for both (ice breakers) 
on a 'what if' basis, just to keep something in the back pocket," Brown 
said.  "That's just prudent planning."

The expanse of sea ice to the north is protecting sea ice nearer, Dettmar
said. Sea ice around the Barnes Glacier and other areas usually riddled
with cracks is remarkably stable.  "Areas where we typically see pressure 
ridges and fairly major cracks, this year what we're seeing is flat," 
Dettmar said. "It's made the ice in some ways easier to travel, but for 
the science groups they don't have anything to study."

Penguins and seals use cracks as doorways. With fewer cracks in McMurdo
Sound and a more distant ice edge, the animals are staying farther out
where they have access to the water and ice. A science group studying Weddell
seals in McMurdo Sound has found 83 adult seals, 10 percent of the normal
numbers. By this time last year about 700 adult seals were in the study
area, which extends from Scott Base to Cape Evans, said seal scientist
Michael Cameron.  "We know that there's a relationship between ice extent 
and the number of animals in the area," Cameron said. He's spent more time 
in helicopters than usual, searching for seals nearer the ice edge.
"To my knowledge this is by far the greatest sea ice extent that's ever
been recorded in this area, and everybody's guess is that it's due to this
giant iceberg blocking the swells," At the same time, scientists studying 
the sea ice actually have an overabundance. Last year the sea ice near 
McMurdo was 40 percent thicker than usual, and this year it's thicker still, 
said scientist Dave Cole, from the Cold Regions Research and Engineering Labs. 
Cole works with a group of scientist studying the structure of ice and how 
it cracks.  "Our overall goal is to develop a better set of models for the 
way ice breaks up," Cole said.  To study that, they cut out free-floating 
blocks of sea ice and record how they react to certain stresses. But if the 
ice is more than a meter deep it is difficult to cut and work with. Though 
they'd prefer to be closer to McMurdo, they had move their camp a few 
kilometers north to Cape Royd's this year to find thin enough ice.

Sea ice researchers off the Antarctic Peninsula also found more ice than
they really hoped. Ice piled up to the railings of the Nathaniel B.  Palmer,
extending the research vessel's cruise in Marguerite Bay.  For more than 
three weeks the research vessel maneuvered in about 197 feet (60 meters) 
of open water in Marguerite Bay south of Palmer Station, surrounded by slabs 
of ice that extend as much as 60 feet below the surface.  Northerly winds 
packed the sea ice in around the Palmer, an ice-strengthened ship. Though 
the Palmer can break through  3 feet (1 meter) of ice CONTINUOUSLY AT A 
SPEED OF 3 KNOTS, AND UP TO 5 METERS OF ICE BACKING AND RAMMING,
the ice surrounding it was too thick, so the crew and passengers had to
wait for the wind to shift and blow the ice away again.  "They're fine, 
they're safe, they're doing science," said Al Hickey, marine superintendent 
for Raytheon Polar Services Company. "They're just going to play a waiting 
game. The ship's in no jeopardy, the people are in no jeopardy."
The cruise was part of a long term ecological research project, studying
the biology and dynamics of the frozen Southern Ocean. This time the
researchers particularly wanted to look at the dynamics of ice.
"They are where they want to be. They got what they want," Hickey said.
"It could probably be termed a very successful cruise." The Palmer was 
scheduled to leave Marguerite Bay on Oct. 14, but the six-day delay was 
not an issue, Hickey said. The ship was stocked with plenty of
food, water and fuel. After the ice opened up again Oct. 20, the Palmer
headed north. It WILL ARRIVE IN PUNTA ARENAS THE MORNING OF 26 OCTOBER.
The Palmer has broken smaller research vessels out of the ice before, but
this was the first time a U.S. Antarctic Program research vessel has been
waylaid in the ice for an extended period of time, Hickey said.
During the delay, scientists and crew on board made the best of the unique
situation, entertaining themselves with music and foosball tournaments.
"They're actually enjoying apparently some incredible scenery, which
obviously they wouldn't get otherwise," Hickey said. "And more opportunity
to conduct science for a longer period than they expected."