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The WISSARD borehole operation on the Ross Ice Shelf
Outside my window, New York City is experiencing a blizzard. The city is on high alert: the mayor is issuing all sorts of proclamations while, at the grocery store, a horde was stripping the shelves bare. Meteorologists and weather scryers warn that the city could be in for up to 36 inches of snow!
Being forced to live under 3 feet of snow is an alarming prospect to me, but it is nothing for the life forms which were just discovered by a team of scientists exploring the extreme ecosystems of Antarctica. The Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project has just drilled through the Ross Ice Shelf—a gigantic sheet of ancient ice which covers an area approximately the size of France. The amazing (albeit stupidly named) WISSARD team drilled through 740 meters (2,430 feet) of shelf ice by means of a specialized hot water drill in order to lower a cylindrical robot submarine into this hidden sea. The insertion point for the probe was near where the ice sheet, the ocean, and the long-buried lands of Antarctica all meet–nearly 850 kilometers (530 miles) from the open ocean. At the converging point of ice, rock, and water, there are vast “grounding lines” of ice which attach the glaciers to the floating Ross sheet. Below the ice, a constant rain of rocks ranging in size from microscopic dust to house size boulders fall upon the sea floor. The temperature of the sea water is 28 degrees Fahrenheit (minus 2 degrees Celsius).
An ice fish and the robot submarine looking at each other
The scientists had speculated that fresh melt water from inland would create an estuarial environment beneath the ice. They found no evidence of that, but they did find all sorts of strange lifeforms. The barrage of rocks keep any sessile lifeforms from finding a home in these waters, but hardy motile sea creatures live there including fish, jellyfish, and amphipods (hardy crustaceans which thrive in extreme environments). The newly discovered Ross fish (which yet lack a name) are the southernmost known fish of the world. They are translucent and pink and measure about 20 centimeters (8 inches) long. As with the crazy underground catfish of South America (which live below the water table), the existence of these ice fish raises an immediate question: what do they live on? The sun shines little through half a mile of solid ice, so what do microorganisms as the base of the food chain use for energy? These organisms do not rely on “cold seeps” (which we explored in a previous post), but the answer is not entirely unrelated. Scientists speculate that the geological upheaval releases nutrients in the form of carbon. It seems that an ancient fossilized ecosystem eroding away into the ocean. The strange fish and sundry invertebrates of the Ross Ice shelf may ultimately be reliant on fossil fuels—which makes them our spiritual brothers for, in this era of cheap frack-gas humankind is more tied to fossil fuels than ever [looks at snow outside and turns up heat].
A fish seen at the Ross Ice Shelf grounding (Deep-SCINI UNL, WISSARD)
Antarctica Seen from Space
Imagine standing high above planet Earth and looking down at the blue and white band of seas surrounding Antarctica. You are looking at one of the most important features of the Earth’s surface. The turning of the planet and strong westerly winds drive the cold deep waters of the Southern Ocean into the planet’s largest and most powerful current system, the Antarctic Circumpolar Current (ACC). The clockwise current isolates the frozen continent into its own self-replicating climate. Since there are no great land masses lying in the ring of open water at these latitudes, the ACC also forces waters from the ocean depths up to the surface. This upwelling brings rich nutrients from the depths and causes immense blooms of phytoplankton (which in turn nurture life throughout all the world-ocean). Additionally the current stirs the circulation of the Atlantic, Pacific, and Indian Oceans.
The ACC has been known to sailors for centuries. A sailing ship can travel west along the current with great speed (if the sailors have the bravery and stamina to confront the fierce winds of “the roaring forties”). The “clipper route” was the fastest sailing route around the world, but it was dangerous. The three great capes (Cape Horn, the Cape of Good Hope, and Cape Leeuwin) all claimed innumerable lives as did wind, ice, and storm. Today the clipper route has been abandoned as self-powered ships bring their cargoes of plastic junk straight across the ocean from China (and then cut across the Panama Canal) but sailing enthusiasts still recognize the fastest way to ride the wind around the planet. The major circumnavigation sailboat races all travel the clipper route.
“Roaring Forties” (Gordon Frickers, oil on canvas)
The true history and significance of the ACC vastly exceeds the paltry recent concerns of navigation and world trade. Geologists estimate that the ACC current began spinning around 34 million years ago at the end of the Eocene epoch as Antarctica split from Australia and drifted further south. Back when Antarctica and Australia were still connected, the great amalgamated continent was a place where cold southern water and chill weather mixed together with tropical warmth—thus causing the whole planet to warm up. However when Antarctica broke away and drifted south, it started a series of climate feedback loops. The oceans around the continent began to freeze and ice started to build up on the mountains. An entire continental ecosystem began to change in the cold. The tropical forests (which had been filled with strange marsupials) began to die and become tundra. As the Oligocene progressed and Drake’s Passage widened, the rivers–once filled with catfish–turned to ice. The landmasses of Antarctica became crushed down under immense glaciers. Antarctica died in the cold. By 15 million years ago it became as it is now–home to only tardigrades, lichen, and a handful of visiting birds and seals.
The Transantarctic Mountains (photo by John Goodge)
Even now the Antarctic Circumpolar Current still isolates the continent from the warmth of the rest of the world. Yet through upwelling of iron and other nutrients, the current bolsters an immense fecundity of phytoplankton–the great primary producer of the ocean. Masses of copepods and krill feed on the algae and the diatoms and they in turn are eaten by fish, mollusks, mammals, birds, filter feeders…everything. The great southern oceans are among the most diverse and strange habitats for living things. It is there that the largest mollusk on the planet is found—which is the subject of an upcoming post.
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