Season project highlights, 2006-2007
The table shows this year’s number of U.S. Antarctic Program research projects and related activities in Antarctica and the Southern Ocean.1 Projects range in size from one person to tens of people, and time in the Antarctic ranges from a few days to years. Some of these 165 science and technical projects are active at more than one location. A few are described in the paragraphs below.
|McMurdo and camps||13||21||15||11||10||4||3|
|1||Aeronomy and Astrophysics||5||Climate and Ocean Sciences|
|2||Biology and Medicine||6||Artists and Writers|
|3||Geology and Geophysics||7||Technical Projects|
- Ten-meter telescope. Construction continues of the 10-meter South Pole Telescope (SPT). The SPT Control Room was substantially completed in the 2006 austral winter. The telescope will be constructed in the 2006-2007 austral summer and begin observations during the 2007 austral winter. During the 2007-2008 austral summer the telescope shield will be erected. The SPT is designed to investigate the properties of dark energy that pervades the Universe and accelerates its expansion, to constrain the mass of the neutrino, to search for the signature of primordial gravitational waves, and to test models of the origin of the Universe. 2
- IceCube. Work continues on the world’s largest neutrino detector, which after 6 years of work will occupy a cubic kilometer of ice beneath the South Pole Station and use 4,200 photomultiplier tubes lowered into holes that made by a specially designed hot water drill. Neutrinos are hard to detect astronomical messengers that carry information from violent cosmological events at the edge of the universe or from the hearts of black holes. Since the 1950s scientists have built a compelling scientific case for doing astronomy and particle physics using high-energy neutrinos. The challenge has been to build the kilometer-sized observatory needed to do the science. An instrument of this size is required to study neutrinos from distant astrophysical sources. Antarctic polar ice has turned out to be an ideal medium for detecting neutrinos, because it is exceptionally pure, transparent and free of radioactivity. A mile below the surface, blue light travels a 100 meters or more through the otherwise dark ice. Frozen in the ice, IceCube will be the largest and most durable particle detector.3
- Long-term ecological research (LTER). Two sites in Antarctica — in the McMurdo Dry Valleys and along the west coast of the Antarctic Peninsula centered on Palmer Station — are among the world’s 25 NSF-sponsored LTER sites being investigated to increase understanding of ecological phenomena over long temporal and large spatial scales (all but one of the other sites are in the United States).4
- Weddell seal population dynamics. Weddell seals in McMurdo Sound have been studied since 1968—one of the longest intensive field investigations of long-lived mammals anywhere. More than 15,000 animals have been tagged, and 145,000 resightings have been recorded. The project is a resource for understanding the population dynamics of not only Weddell seals, but also other species of terrestrial and marine mammals. New work this season includes assessing the role of food resources in limiting the populations.5
- Adelie penguin populations and climate change. The Adélie penguin is tied to sea ice, a key environmental variable affected by rapid climate change. Researchers will investigate the populations of Adélie penguins on Ross and Beaufort Islands, where colonies have recently expanded, relative to colonies at Cape Crozier that declined during the 1960s and 1970s. The information will be related to sea ice, as quantified by satellite images. Understanding the mechanisms behind this sensitivity will contribute greatly to predicting the effects of climate change on Antarctic marine organisms.6
- Ocean acidification and marine ecosystems. As global carbon dioxide levels rise, the acidity of the southern ocean will increase. Excessive acidity in the marine environment can negatively affect the metabolism of planktonic marine organisms, including the ability to form shells. Researchers will evaluate the impact of elevated carbon dioxide on calcification, metabolic physiology, and organismal performance in Antarctic pteropods, an abundant, butterfly-like snail that lives in the southern ocean waters. They will begin to evaluate how impacts on the pteropod population affect the function of the larger marine ecosystem. 7
- Protein function in cold-adapted fish. Antarctic fish live in an unusually cold environment where basic processes such as protein synthesis are thermodynamically challenging. Researchers are examining whether Antarctic fish have unique adaptations for making proteins and are uncovering the genetic basis for these functions. Comparative studies with temperate fish will help to illuminate the evolutionary pathways of cold-adaptation and life in extreme environments. 8
- Influence of light, iron and carbon dioxide on Ross Sea productivity and biogeochemical cycling. The Ross Sea is a region of intense biological productivity, where phytoplankton biomass is dominated by two main taxonomic groups: diatoms and Phaeocystis. It is well known that these two phytoplankton groups have different impacts on biogeochemical cycles in the Ross Sea, but the factors that control their relative abundance are not well understood. Researchers will investigate the effects of iron, carbon dioxide, and light levels in the Ross Sea on phytoplankton community structure. These studies will contribute to a broader understanding of carbon and sulfur cycling in the Southern Ocean. 9
- Demonstration ocean-bottom drilling in the James Ross Basin. Scientists will deploy a drill rig on the research icebreaker Nathaniel B. Palmer to test the feasibility of ship-based diamond coring along the antarctic continental margin. If successful, this Shaldril mobile system will be able to explore the “no man's land” between the nearshore (where the fast-ice-based Cape Roberts Project was successful) and the upper slope (where ODP's JOIDES Resolution becomes most efficient).10
- Seismograph. The world’s quietest earthquake detector is 8 kilometers from the South Pole, 300 meters beneath the ice sheet surface. Completed in 2002, the station is detecting vibrations four times smaller than those recorded previously. Other seismographs have been there since 1957, and long-term, high-latitude data have helped to prove that the Earth’s solid inner core spins faster than the rest of the planet. Also, Antarctica is the continent with the fewest earthquakes, so the new station will record small regional earthquakes, leading to new insights into the Antarctic Plate.11
- Behavior of the world’s largest icebergs. This research team will investigate the basic principles governing the calving, drifting, melting, break-up, and environmental impact of large icebergs. Because the northward drift of large tabular icebergs represents a natural “climate change” experiment on an accelerated time-scale, the melting of the icebergs being studied over the next decade will foretell events that may occur in parts of Antarctica as climate conditions change over the coming century. Understanding the natural drift patterns and regions where icebergs accumulate near inhabited parts of the globe may someday prove useful for supplying fresh water to populations in need, as far-fetched as that may be with current technology.12
- ANDRILL, a scientific drilling program to investigate Antarctica's role in global climate change over the last 60 million years, integrates geophysical surveys, new drilling technology, multidisciplinary core analysis, and ice-sheet modeling to address four scientific themes:
- the history of Antarctica's climate and ice sheets;
- the evolution of polar biota and ecosystems;
- the timing and nature of major tectonic and volcanic episodes; and
- the role of Antarctica in the Earth's ocean-climate system.
- WAIS Divide.
This 5-year science program, involving a dozen research teams, will develop a detailed record of greenhouse gases for the last 100,000 years; determine if changes in the Northern and Southern Hemispheres initiated climate changes over the last 100,000 years; investigate past and future changes in the West Antarctic Ice Sheet; and study the biology of deep ice. During the 2005-2006 austral summer, the camp infrastructure to support the drilling program was assembled at a site on the West Antarctic ice sheet divide. Construction crews established a skiway and a camp capable of supporting approximately 45 personnel. This camp is opened for the austral summer seasons only and is supported by LC-130 Hercules aircraft for all heavy cargo loads and fuel deliveries. The entire camp is taken down for winter storage because of the high snow accumulation rates that occur over the austral winter period. A 184-foot steel arch building that will house the drilling and core processing facilities for the deep drilling project was constructed last season with interior construction continuing during the 2006-07 austral summer. The facility will eventually support the science and drilling teams who will collect a 3,400-meter ice core to bedrock. Drilling is expected to begin during the 2007-08 field (austral summer) season. As ice cores are produced in the field, the cores will be flown back to McMurdo Station for shipment to the National Ice Core Laboratory in Denver, Colorado (NICL). NICL will then distribute core samples to individual researchers.14
- International Transantarctic Scientific Expedition (ITASE) Researchers will continue studies of the last 200 years of environmental history of East Antarctica by means of ice coring and data collection along a traverse route from Taylor Dome to South Pole. These proxy climate histories will help determine anthropogenic influence on air temperature, atmospheric circulation, and atmospheric chemistry. This research enables regional comparisons of interannual variability of climate and the records can be extended from the last two decades of satellite and field observations to the last 200 years, through the interpretation of ice core-derived climate and environmental proxies.
- Grounding line forensics: Kamb Ice Stream. This project will address key questions concerning the mechanisms governing changes in ice streams by studying the dynamics of ice stream interaction and shutdown, in particular ice stream outlet dynamics (i.e. grounding line migration). Researchers intend to investigate several key features in the Kamb/Whillans ice stream area that will provide additional details to the evolving description of ice flow history in the region. The research effort is targeted at sites that can be used to test scenarios implied by satellite image analysis, modeling studies, and prior field work. The information obtained will contribute to a fundamental understanding of ice sheet dynamics and the effects of global warming and sea level rise on ice sheets.
- Old buried ice. Ice has covered Antarctica for millions years, but the ice is not that old; most of it arrives as snow and leaves as icebergs within a few hundred thousand years. Buried ice in the McMurdo Dry Valleys thus is a rare archive of atmosphere and climate potentially extending back millions of years. This project will study the surface processes that preserve ice, test ways of dating tills above buried ice, assess ways to date buried ice, and use these data to help resolve a debate over whether the deposits are as old as some scientists think they are.16
- Infrared measurement of the atmosphere. Winter measurements of atmospheric chemistry are providing data for predicting ozone depletion and climate change. Since most satellites do not sample polar regions in winter, these ground-based measurements are expected to make important contributions.17
- Surface carbon dioxide in the Drake Passage. The Southern Ocean is an important part of the global carbon budget, and the Drake Passage is the narrowest place through which the Antarctic Circumpolar Current goes. This chokepoint is an efficient site to measure the latitudinal gradients of gas exchange, and the ice-strengthened research ship Laurence M. Gould will support a project to measure dissolved and total CO2, providing data that, with satellite images, will enable estimates of the net production and export of carbon by oceanic biota.18
- Antarctic Artists and Writers Program. Five artists will deploy to Antarctica this season. Four of them will deploy to the McMurdo area between August and January. Among them are Anne Aghion a documentary filmmaker, Lita Albuquerque an installation earth artist, Xavier Cortada a painter and installation artist, and Werner Herzog a filmmaker. One artist will deploy to Palmer Station, glass sculptor, David Ruth. A sixth award was given to installation artist, Dove Bradshaw to receive Antarctic salt from the desalination plant (no travel to Antarctica.)
- Ice Coring Drilling Services. This project, one of the technical services in support of antarctic science, provides ice core drilling to the U.S. Antarctic Program and NSF’s Arctic Research Program.19
This long-term program focuses on two previously inaccessible sediment records beneath the McMurdo Ice Shelf and in south McMurdo Sound. These stratigraphic records cover critical periods in the development of Antarctica's major ice sheets. The McMurdo Ice Shelf site focuses on the Ross Ice Shelf, the size of which is a sensitive indicator of global climate change. The core obtained from this site will offer insight into changes in size of the shelf since the last glacial maximum; sub-ice shelf sedimentary, biologic, and oceanographic processes; the history of Ross Island volcanism; and the lithosphere’s response to volcanic loading, which is important for geophysical and tectonic studies of the region. As a generator of cold bottom water, the shelf may also play a key role in ocean circulation. The south McMurdo Sound site, adjacent to the Dry Valleys, offers a view into the major ice sheet overlying East Antarctica and the debate regarding the stability of this ice sheet. Evidence from the Dry Valleys supports contradictory conclusions — a stable ice sheet for at least the last 15 million years or an active ice sheet that cycled through expansions and contractions as recently as a few millions of years ago. Constraining this history is critical to global climate change models. The sediment cores will be used to construct an overall glacial and interglacial history for the region; including documentation of sea-ice coverage, sea level, terrestrial vegetation, and melt-water discharge events. The core will also provide a general chronostratigraphic framework for regional seismic studies and help unravel the area's complex tectonic history.13
| For each project with an NSF grant, a description including contact information and grant amount is in the Foundation’s grants database, http://www.fastlane.nsf.gov/a6/A6SrchAwdf.htm.|
| LTER network: http://lternet.edu/; McMurdo LTER: http://huey.colorado.edu/LTER/; Palmer LTER: http://iceflo.icess.ucsb.edu:8080/ice_hp.php?|