You're Not So Tough After All, Drake Passage

Freeze Frame: Sights, Sounds And Science From The Bottom Of The World NPR science producer Jason Orfanon guest blogs as he journeys to the Antarctic Peninsula. Keep up with him on Twitter: "@jorfanon." And view the whole series page.

By Jason Orfanon

The Drake Passage is a deep patch of water spanning 600 miles between Cape Horn and the South Shetland Islands. This is where the Atlantic and Pacific oceans collide, whipping up what many consider the roughest, most menacing seas in the world.

Now that we're nearly through the Drake, I can safely say it: We got lucky. The swells have been about 10-15 feet, much more manageable than the 35-footers I'd heard of prior to the voyage.

According to the Laurence M. Gould's second mate, Collin Hodgson, you never really know what to expect from the Drake. One day it can be relatively calm; the next it can toss a ship around like a cork in a bathtub. "It's the most gnarly place in the world," he says.

For Dave Barbeau of the University of South Carolina, the Drake Passage is more than just an obstacle to be crossed. He wants to know when it was born.

Barbeau believes that ocean currents — like the Gulf Stream that keeps Northern Europe comparatively mild — once bathed the Antarctic coast with warmer water, making for higher temperatures, and much less ice. From 100 to 34 million years ago, he says, Antarctica was largely glacier-free.

According to Barbeau's hypothesis, all that changed when South America and the Antarctic Peninsula broke apart, creating the Drake Passage. Powerful new currents prevented the warm currents from reaching Antarctica. Without the influx of waters from the north, temperatures dropped, and Antarctica began looking like the ice-covered continent we know today.

This idea goes against the conventional wisdom that the Drake opened too late to have influenced ice formation on Antarctica. But Barbeau says his recent findings support the claim.

"Our research is providing convincing evidence that the passage may have been opening much earlier, prior to 34 million years ago, which would have allowed the circulation of cold polar waters around Antarctica, isolating it from warmer subtropical currents that previously may have kept it ice free," he says.

Over the next several weeks, Barbeau and his team will be camped out on islands in the northern Antarctic Peninsula, collecting and analyzing as many rocks as they can get their hands on. With this information — and more like it from the southern tip of South America — Barbeau should be able to determine when the two continents broke apart and see if it corresponds with Antarctica's big chill.

For now, his team still has a few days before they trade warm berths and laptops for cold tents and rock hammers. And for those of us headed to Palmer Station, the "getting there" part of the journey is nearly over. This time tomorrow, we'll be in Antarctica.

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