Day 4: Touring By Helicopter
Secretary Clough visits the driest place on the planet, Ernest Shackleton’s hut, penguins, whales and more on his final day in Antarctica
- By G. Wayne Clough, Secretary of the Smithsonian Institution
- Smithsonian.com, February 19, 2010, Subscribe
(Page 2 of 4)
Our first stop takes us up Taylor Valley to Lake Hoare where a research team working with Diana Wall of Colorado State University is studying interactions between climate and other global changes on the abundance, diversity and distribution of soil biota. Looming like a massive white curtain wall across the east side of the valley floor is the 50-foot front of a glacier that has intruded itself just downstream of Lake Hoare after travelling down from a higher valley and making a sharp right turn into Lake Hoare where it appears like an uninvited guest. As we take a moment to look around, we are surprised to come upon the bodies of a penguin and a seal lying at the foot of the glacial front. Amazingly, these creatures had apparently made their way across the vast expanse of the glacier lying in the entrance to Taylor Valley only to fall over the precipice of the front. We are told these animals likely lost their way due to some failure of their natural navigation system and just kept going until their fate was sealed. In this arid and cold climate without the presence of scavengers, bodies mummify and remain for years. The Antarctic does not give mercy to those who make mistakes.
Lake Hoare lies in a valley surrounded by steep walls with exposed, bare rock showing sculpted scars created by the valley glaciers during the last period of glacial advance around 20,000 years ago. The valley walls exhibit faults and magmatic dikes that cut across the beds. These rocks are much older than the Antarctic continent itself, having been part of the ancient supercontinent Gondwana before it separated into today’s many parts. Standing in this spot you can see direct evidence for the power of nature and sense its patient processes: Tectonic plate movements that move continents and make mountains where none existed, winds that scour rocks and pulverize them, glaciers that silently move and strip bare rock walls, gravity that brings down big boulders so that the bounce like toys into the glaciers below, and freezing water that expands and cracks even the hardest rock. Humans have a difficult time appreciating all of this even though it is massive and constant because nature works on such a long time scale. We live on average 75 years and our species only goes back about 200,000 years, a blink in the eye of nature. Yet we are beginning to become something of a geologic force ourselves, because the cumulative impact of 7 billion of us on the planet is having an effect.
The camp at Lake Hoare consists of a few buildings, mainly housing laboratory equipment, and a series of individual tents for the scientists, set apart from each other to provide some degree of privacy.
This camp has more than the norm in the way of facilities because it is a base for other camps up the valleys. Its operations are run by Sharon (Rae) Spain, a contractor for the NSF Polar Program, who is famed for her ability to make things work in this remote and difficult environment. Rae is so outgoing and enthusiastic it is immediately apparent that she loves the life she lives here.
In fact, every member of Diana’s team is enthusiastic about the work they are doing and each brings different skill sets to the project at hand. I am pleased to meet Dr. Fred Ogden from the University of Wyoming, a hydrologist studying water and moisture movement, who is also a research associate at the Smithsonian Tropical Research Institute in Panama. Antarctica is a long way from the tropics, and I ask about his research. He is studying water flow to develop better hydrologic models for forecasting as part of the Agua Salud project. Shallow subsurface water flow is an important part of the Panama Canal watershed and since all subsurface water flow is shallow in Antarctica because of the permafrost, it is actually simpler to study.
Lake Hoare itself is not a large lake, but is significant and saline. The beach is composed of a dark soil with inclusions of rocks that have fallen into it from the valley walls. There are octagonal patterns in the soil that mimic those seen in dry lake beds in the desert. Talus deposits of soil and rock (or scree, broken bits of rock) rise from the beach towards the valley walls. Where these deposits have a smooth surface, they are often eroded with V-shaped channels that appear to have been created by water. Beneath them as they lead to the lake, the soil appears darker.
The science team helps us understand what we see. Fred and Joe Levy from Portland State University explain that the V-shaped features we see in the talus slopes are indeed water induced, forming during an especially warm day as a pulse of melt water from the glaciers above flows in small streams downward toward the lake. The dark areas on the soil are created by the melt water but reflect small flows that continue from above but remain underground. As to the octagonal features, these develop with freezing and thawing cycles in the permafrost, much as are seen in permafrost in the Arctic.
So, there is water here in the soil but it is intermittent and comes very rarely. How is life sustained in the frigid, arid environment of the Dry Valleys? This is another matter of study for Diana and her team. They look for a creature known as a nematode that is all of a millimeter long and resides in the soil. A nematode may be small, but it is mighty in its evolved ability to survive in a hostile environment. This tiny creature understands that it lives two lives, one for the long dry times and one for the fleeting times when a small drop of moisture might come its way. During dry times it can give up almost all of its body moisture and simply stop normal body activities. It can lie patiently dormant for tens of years, but give it a bit of moisture and it will absorb it and come back to life, making the most of the moment. Why should any of this be of interest to us? First, as noted, these dry valleys may mimic similar environments on moisture-deprived Mars and other planets. We can learn how to look for life on other planets by studying these unusual creatures. Second, with climate change, creatures like the nematode may disappear, so we need to do all we can to understand them now. We can best deal with the effects of climate change if we understand what it does in all of its ramifications for the earth.
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