Sex, Drugs, and Public Health

February 16, 2014

DAY SEVEN AT SEA

Filed under: Uncategorized — cbmosher @ 6:36 am

Sarah says she came for the ice, more than for the wildlife. An increasing number of guests say they came for the wildlife, but are now more fascinated by the ice.

 

Every ‘berg is unique. They are continually sculpted by the sea, sometimes adding icicles. Often flipping to reveal a different face. Sometimes jamming a harbor so tightly, that it’s inaccessible (as was the Weddell sea for us).

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There are dozens of names for ice here and in the Arctic, but two major categories are: Sea Ice and Land Ice.

 

The first is what forms on the surface of the ocean when the salt water gets cold enuf in winter – 28.5 degrees F. It starts as a slurry, then becomes floating pancakes. These fuse into a surface of ice extending miles beyond shoreline.

 

Land Ice starts as snow falling, trapping air. As it builds up over the centuries, it gets heavier, compresses the air, and re-arranges its crystals as ice. Then it begins to flow, rivers of ice joining in the downslope run, into a glacier at the edge of the sea.

 

The Land Ice, because of the trapped air, is lighter. Once it breaks free of the glacier, it floats a little higher in the ocean than the Sea Ice.

 

 

We’ve seen millions of tons of ice.  Billions. Oozing down the valleys in place of water, floating free in the open ocean, in harbors, and in coves. The sheer volume of it is nearly ungraspable.

 

Then you look at a map. We’ve seen just 1% of the continent’s land and ice mass. The area called “Greater Antarctica” is entirely covered by an ice cap. Scientists have plotted the mountain range, individual peaks, and plateaus beneath the ice.

 

But 35 Million years of sparse snowfall (this is a desert – only six inches of water equivalent falls each year) and no years of melting have left that ice cap three miles thick in some places. The  ice is so heavy, that we are told much of the landmass (i.e. rock) has been pushed down below sea level. It would be a land of islands if the ice cap were removed.

 

Given the size and numbers of bergs, you wonder if Antarctica is losing ice faster than it’s accumulating it. So have the scientists.

 

As the snow falls, it traps small quantities of air and soot (e.g. from volcanoes). Thus, scientists have been able to take core samples, bored from the ice, and measure the level of various gasses in the Earth’s atmosphere over centuries. Then we can compare those readings with today’s levels.

 

The result:  CO2 levels in the atmosphere have fluctuated over the last 30,000,000 years. The highest level reached during that time was 280.

 

Today CO2 levels are over 400 and rising. A new record for the last thirty million years.

 

All the glaciers on this peninsula are retreating.

 

Regarding the wildlife: two days ago, our ship made its way into Paradise Harbor where snow, wind, cold and waves thrashed the ocean. Captain ran the ship aground to anchor us – an interesting technique – and we took a wet Zodiac ride among the icebergs. The highlite was a Leopard seal swimming within hands’ reach, fangs bared.

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It had been prowling the shore, waiting for dinner to enter the surf and swim by. But the penguin babies were still molting their birth down into waterproof feathers. No water experience for them until next week. Back to his ice floe for the sleek, heavily muscled number two predator in Antarctica. He fills the niche where you find Polar bears in the northern land of ice. And these seals are so comfortable on ice floes, that’s where they breed and raise their pups, far from land.

 

Yesterday Sarah took another Zodiac ride among the icebergs (the final of the trip) and a Humpback whale surfaced just off the beam, almost within touching distance. It then turned on its side to feed, expanding its pleats, and scooping up a vast quantity of water and krill. They hunt where the krill is, of course, and the krill breeds beneath the ice.

7 Humpback

So, I would add to the list for this continent of superlatives (the Highest, the Driest, the Coldest, the Windiest, the Loneliest) this: the Iciest. 80% of our planet’s fresh water is frozen solid here, for safekeeping and for regulation of our weather.

 

There’s work to be done, protecting this most spectacularly beautiful ad untouched continent: preventing the continuing trend toward ever higher CO2 levels, and ever quicker retreat of glaciers. Not just for the Leopard seals and Humpbacks, but for our grandchildren and, indeed, for the entire planet.

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