Antarctica's Hot Spot - area in Antarctica is warming faster than anywhere on earth

What sinks to the ocean floor depends in part on the climate. When it's cold enough to form ice shelves that extend over the Antarctic landmass and into the ocean, much of what drops to the seafloor is sand and gravel that the glacier has picked up on its slow march from the continent's ice cap. Sandy ocean sediment is associated with ice cover, and when you find it somewhere far from the ice edge, you know that at some point the ice reached that site. When the weather warms and no ice sits upon the seas, the sediment on the ocean floor is mainly organic: remains of plankton and diatoms. By reading the ups and downs of organic versus nonorganic sediment in a core, sedimentologists can follow the retreats and advances of ice over the past 20,000 years. So far, ice cores from Greenland and marine sediment cores from Antarctica have shown that a notable warming period occurred from 3,000 to 8,000 years ago. Nobody knows for sure why that warming took place. The point of taking core samples, says Colgate University marine geologist Amy Leventer, one of the two chief scientists on this voyage, is to figure out how much warming has been natural in the past. That will help researchers understand the role of human interference in the current warming trend.

YESTERDAY'S STORM HAS MOVED ON, leaving behind an unearthly stillness broken only by the calls of snow petrels and the engine's throaty hum. We have arrived at the mouth of the Muller Ice Shelf, near Lallemand Fjord. For those who picture Antarctica as a monotony of whites and grays, Lallemand Fjord is an awakening. The icebergs crowding the ship this morning are infused with a paint store panoply of blues, many of them arrestingly unnatural--the bright, blaring blues of mouthwashes and toilet bowl cleaners. It is not merely the variety of hues that dazzles but the intensity. The color appears to come from within, like the glow in a smoldering piece of coal. Pretty much everyone is out on deck, looking at the ice.

Not all of them are thinking nice thoughts about it. One of the detractors is Gene Domack, a sedimentologist from Hamilton College in Clinton, New York, and the trip's other chief scientist. He and graduate student Asa Chong left a series of ocean sediment traps moored in the water here last year, to be recovered this morning. "The ice shelf has advanced over the tops of the traps," says Domack, practically chewing on his mustache. Chong's traps were left close to the edge of the ice shelf intentionally If you are planning to study the advance and retreat of ice shelves over the millennia, you need to be able to recognize the unique sediment profile of an ice edge. A more detailed familiarity with one year's worth of sediment (generally about 7 to 12 inches) also helps scientists interpret the timetable of the longer cores.

As it turns out, the ice shelf hasn't covered the traps after all. But huge chunks of ice, some the size of a bus, have broken off the shelf. Maneuvering the ship around these dangerous hulks without colliding with them is tricky Using the Global Positioning System measurements taken from last year's trip, the crew moves to confirm the traps' location with the aid of sonar. Once a trap is pinpointed, the crew tries to snag it on a grappling hook lowered over the back of the ship. For the next half hour, the ship cruises slowly forward and back, like a police rig dragging for a corpse. Eventually, the sediment traps, looking like upside-down traffic cones, are hooked and hauled aboard.