Southern end of James Ross Island. Photograph by Maria Stenzel 

The helicopter ferried us 30 miles from the Nathaniel B. Palmer on this cold, whitewashed morning. Our destination was a rocky outcrop near the end of the two-mile-wide Boydell Glacier, where it crumbles into the sea on the east edge of the Antarctic Peninsula.

As our helo drifted toward the landing site I spotted a lone seal hefting its way up the jumble of rocks and ice. You have to wonder what exactly the guy had in mind climbing a mountain in that kind of footwear.

Flying over over a seamount named Jun Jaeguy, a submarine volcano that appears to be inactive at the moment. Photograph by Maria Stenzel

64.43 degrees south latitude
57.61 degrees west longitude

Our ship has once again been repelled by sea ice—this time more ominously than before. We now know for certain that we will not reach Larsen B. It's hard to imagine how disappointed these scientists must feel. They've been planning this expedition for three years. Their careers depend on it.

Sea ice and icebergs surround the Nathaniel B. Palmer—which is now trapped. Photograph by Maria Stenzel

64.52 degrees south latitude
57.99 degrees west longitude

Gossip overheard in the food line of the Nathaniel B. Palmer tells you exactly where we are in this cruise. “I hear the lettuce is about to end,” says one diner. “I'm not surprised—it's about that time,” says the other, a salty seafarer and grad student from Lamont-Doherty Earth Observatory in New York City. 

We knew this was coming. Our cruise, now lumbering into its fifth week, has exceeded the longevity of our fresh food. Cantaloupe and watermelon petered out a few days ago. Tomatoes soon after that. And several days later our last bananas—geriatric and brown—also disappeared. They were replaced by banana bread, which itself quickly vanished. 

As the cruise enters new gastronomic waters, it enters new geographic ones as well. Several days ago our ship rounded the northern tip of the Antarctic Peninsula and crossed to the east side—our third, desperate attempt to penetrate the unusually heavy sea ice, which has kept us from reaching the goal of this expedition: the remnants of the Larsen B Ice Shelf. 

We were awakened at 5:30 a.m. for a helicopter briefing. Brilliant weather this morning in Barilari Bay, on the west side of the Antarctic Peninsula. Blue skies—the first in 14 days. Management was determined to make full use of a rare opportunity.

Our ship sits in Flandres Bay, a deep fjord on the Antarctic Peninsula ringed by mountains whose sheer granite torsos fade, headless, into a ceiling of mist. The air is still. The water is glass. And rain—Who'da thunk it? Rain in Antarctica!—scatters ripples onto the bay.

Today’s muggy 36 degrees Fahrenheit finds me tossing aside my down jacket as I head outside. I walk into the drizzle wearing blue jeans and a light synthetic pullover. From the top deck of the Nathaniel B. Palmer one can see half a dozen humpback whales feeding on swarms of krill. At times, two of them pause and lazily hover side by side—so close they must be touching—just below the water’s surface.

The Palmer sailed for several days to reach this place on the west side of the peninsula, after turning back twice in the face of impassable sea ice on the east side.

The west is a different place. The low-pressure weather systems that sashay in an endless parade around Antarctica dump their full weight of warmth and precipitation on the western edge of the peninsula. Sea ice that forms during winter doesn’t survive summers here; since arriving three days ago, we haven’t seen a speck of it. The heavy snowfall gluts glaciers beyond their capacity. All around us traffic jams of ice blocks tumble out of the mountains, in freeze-frame, down 45-degree chutes to the water's edge. Without any familiar frames of reference such as cars or trees, the mind can scarcely comprehend the size of the scenery. The nearest glacier seems a couple hundred yards away. In fact, it’s more than a mile. Those blocks of ice are as big as houses.

Map showing the path of the Nathaniel B. Palmer from January 4, when it left the port of Punta Arenas, Chile, at the tip of South America, until January 11. The ship has twice been turned back by impassable sea ice on the east side of the Antarctic Peninsula.

We’re now ten days into our 59-day cruise to investigate the breakup of the Larsen B Ice Shelf, and the difficulties of working in Antarctica—even in this day and age—are already apparent. Sea ice has emerged as our prime nemesis. Twice we have tried to limbo our way under the 65-degree latitude line—our goal sits at 66 degrees south—and both times sea ice has blocked our path.

64.28 degrees South latitude
58.86 degrees West longitude

It's a scorching day by Antarctic standards—47 degrees Fahrenheit and a cloudless sky. Two hours ago a helicopter ferried us from the Nathaniel B. Palmer to this rocky nunatak, or mountain, that juts from an apron of glacial ice on the coast of the Antarctic Peninsula. As we hiked, I quickly peeled off my jacket, hat, and gloves and pushed my sleeves up to the elbow.

Greg Balco, a glacial geologist from the Berkeley Geochronology Center in California, strides up a slope of loose scree, steadying himself with trekking poles. Balco is hunting for the perfect rock—one that will reveal the glacial history of this place—but today his job is almost impossible.

At 3 p.m. on this dim, socked-in afternoon, the Nathaniel B. Palmer reached its rendezvous point—63.7658 degrees south, 56.8273 degrees west—an unremarkable patch of water littered with scraps of sea ice. Ten months earlier a treasure had been dropped into the sea at this spot and anchored to the muddy bottom, 2,112 feet below, by a lead weight. On this day Craig Smith, a marine ecologist from the University of Hawaii at Manoa, was returning on the Palmer to reclaim his treasure. His prospects looked grim.

Rough weather this morning. We’re just under halfway across the Drake Passage, which separates South America from Antarctica, and the sea is handing us a whipping. Winds up to 55 knots and gusts up to 100 have piled the sea into an endless stampede of rolling swells. 

As I step out of bed, my bare feet slide across the tilting floor—right, then left, then right again. I resort to sitting on the floor as I gather my things. Showering while holding on white-knuckled with one hand, lathering with the other, and bracing both feet evokes a feeling of absurdity—an attempt to maintain normalcy when things are in fact far from normal, like awakening into an episode of Laverne & Shirley or I Love Lucy. Except in this case the hanging on isn’t just funny; it’s all that separates me from serious injury.

 54.17 degrees South latitude
 70.90 degrees West longitude

Welcome to the town of Punta Arenas, Chile, at the southern tip of South America. At the pier sits the Nathaniel B. Palmer, a 308-foot icebreaker and research vessel operated by the United States Antarctic Program. 

We’ll soon head south on this ship across the Drake Passage, and sail along the edge of the Antarctic Peninsula, a finger of land that reaches up from the main part of Antarctica and tickles the dangling nubbin of South America. On board the Palmer are roughly two dozen scientists and several dozen crew—plus a trio of journalists on assignment with National Geographic: Maria Stenzel, photographer; Sarah Park, videographer; and myself, Douglas Fox, the writer.

Our voyage will last 59 days; we plan to return to port on March 2 or so. The purpose of the trip is to study how Antarctica is responding to rising temperatures—and no better place to do it than the Antarctic Peninsula, where average temperatures have risen 4.5 degrees Fahrenheit in the past 50 years—nearly five times as quickly as in most other parts of the planet. The ice in this part of Antarctica has seen some dramatic, in some cases even catastrophic, changes. More on that in a minute.