A Vision for the International Polar Year 2007-2008 (2004) / Chapter Skim
Currently Skimming:
4 Exploring Scientific Frontiers
4 Exploring Scientific Frontiers
Pages 41-53
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 41... ...
EXPLORING LIFE IN THE POLAR REGIONS The extremes of temperature, the ice cover, and the marked seasonal variation in day length that characterize the polar regions confront organisms with a challenging set of environmental conditions. Yet the apparent "hostility" of the Arctic and Antarctic environments has not precluded the evolution of complex ecosystems whose constituent species have adapted in novel ways to the extreme physical conditions they face.
|
From page 42... ...
Many new species of polar organisms remain to be discovered, as shown by the recent finding of new species of invertebrate and vertebrate marine life through the internationally organized Census of Marine Life project.1 The biology of the polar regions thus represents a fascinating frontier for exploration, where rewards in both basic and applied science are waiting (NRC, 2003a)
|
From page 43... ...
We are poised to explore the world of polar microbiology in wholly new ways, and this work will open up important new understanding of the pivotal role that microbes play in all polar ecosystems. Biotechnology and Biomedicine The remarkable abilities of plants and animals native to polar regions to withstand extremes of low temperature and, in many cases, wide ranges of temperature represent a promising biological frontier for exploration.
|
From page 44... ...
their body fluids. Small mammalian hibernators such as ground squirrels allow their core body temperature to fall to approximately 2°C.
|
From page 45... ...
, and large subglacial lakes, isolated from the rest of the biosphere for many millions of years, that may hold a variety of ancient forms of life? Polar Ecology Inasmuch as new technologies offer the means to explore the genomes and physiologies of polar species, new tools are becoming available that allow novel types of exploration of large and complex terrestrial and aquatic ecosystems in the polar regions (NRC, 2003a)
|
From page 46... ...
And, as discussed above, the recently acquired abilities to determine the types of microbes present in an ecosystem and to elucidate the physiological activities of these important organisms open up an especially important new avenue of exploration in polar ecosystems. EXPLORING NEW REGIONS Subglacial Lake Environments Recent discoveries show that buried under miles of Antarctic ice are subglacial lakes ranging in size from Lake Vostok (Figure 4.1)
|
From page 47... ...
These subglacial environments provide an unparalleled opportunity to advance our understanding of how climatic and geological factors have combined to produce a unique and isolated biome that may be occupied by yet unknown microbial communities. Subglacial lake exploration poses one of the most challenging scientific, environmental, and technological issues facing polar science today.
|
From page 48... ...
The nature of the underlying bedrock is a crucial boundary condition that defines the stability of the ice sheet to climatic changes. The subglacial topography is key to ice sheet models in part because the distribution of highlands strongly defines when, where, and how glaciation initiates (DeConto and Pollard, 2003)
|
From page 49... ...
Ocean Basins The polar ocean basins beneath sea ice represent vast unexplored regions that can now be studied with modern technology, such as remotely operated vehicles and autonomous underwater vehicles. These advances will allow biologists to investigate questions about variations in ecosystems between the ice edge and regions deep within the ice pack and the types of seasonality found beneath floating ice shelves.
|
From page 50... ...
Red colors denote slow velocities associated with hot and upwelling regions in the mantle, and blue colors denote fast velocities resulting from cooler temperatures and downwelling regions. The warmer mantle regions are associated with magma production, polar volcanism, rapid postglacial rebound, and increased heat flow beneath glaciers.
|
From page 51... ...
The increased magmatism and mantle flow associated with the Iceland hotspot may have had a large effect on the tectonic and climatic evolution of Greenland and the Arctic basin. Investigation of mantle anomalies beneath the Gakkel Ridge may provide the first direct evidence of the distribution of melt production regions along an ultra-slow-spreading center.
|
From page 52... ...
Global cloud cover data, including in the polar regions, which are important for models and which can be affected by solar emissions and their variability, are almost absent from databases of the polar environment. Except for the past 10 years or so, actual data on solar variability that need to be incorporated into models are largely by proxy from studies of polar and glacial ice sheets, ocean sediments, and other terrestrial sources.
|
From page 53... ...
He has also worked on the permanently frozen Dry Valley lakes and has a current interest in Lake Vostok, a newly discovered subglacial lake about the size of Lake Ontario that is under miles of Antarctic ice. Subglacial lakes are of keen interest because no one knows if they hold life or understands the biochemical processes that must exist to sustain life without sunlight, with low nutrient inputs, and in temperatures below freezing.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.