Future research in the Transantarctic Mountains
1) The research community attending the 2013 Transantarctic Mountains Science meeting in addition to the open call for comments produced and shaped the below attached document (Landscape and Life). The document is a first step towards determining the broad scientific goals and challenges that can only be resolved by interdisciplinary research in the Transantarctic Mountains.
2) As the next Antarctic proposal deadline is fast approaching 4/15/2014 I would like to encourage everyone to submit proposals to the Antarctic Research programs. This is the only way to justify future TAM camps and strong continuation of research in the TAM. This is particularly important now that a new TAM camp is being planned at the Shackleton glacier (http://tamcamp.org/camp/selected).
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cheers
Jaakko
Jaakko Putkonen, Ph.D, Assistant Professor
Harold Hamm School of Geology and Geological Engineering, MS 8358
University of North Dakota
Grand Forks, ND 58202-8358
USA
tel: 701-777-3213
fax: 701-777-4449
Homepage: http://sites.google.com/site/undgeomorphology/home
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Landscape and Life;
Future interdisciplinary research priorities in the Transantarctic Mountains
Compiled and edited by Jaakko Putkonen, John Isbell, Kathy Licht, and Nathan Smith.
2/24/2014
Background
On 9/22-25/2013 sixty-one scientists, students, support personnel, and teachers from the USA, Russia, Japan, New Zealand, and Belgium, participated in the Transantarctic Mountains Science meeting held in Minneapolis, MN. The participants represented all major fields of research conducted in the Transantarctic Mountains (TAM) including life-sciences, geology, glaciology, atmospheric sciences, and geophysics. In addition to exchanging recent research findings and building interdisciplinary bridges, the attendees spent significant time identifying outstanding science questions that can only be answered by research in TAM.
This document is based on the small group sessions and community discussion at the 2013 TAM Science meeting. The draft of this document was circulated for comments from currently active researchers interested in TAM Science. This document strives to be the first step towards articulating the overarching questions and broad scientific challenges that motivate future research in TAM.
TAM is a unique laboratory that contains rock exposures recording the evolution of the Antarctic continent since the Archean. For the last 350 Ma of that history, Antarctica has been located in a polar or near polar position, making it the only place on Earth that provides a deep time perspective on the physical, chemical, and biotic development of Earth’s modern polar system. TAM also contains extensive 3-D exposures of rocks and landforms on ice-free slopes and in valleys, affording nearly 100,000 km2 of exposure and making it a rich natural archive. Therefore, a concerted scientific effort in TAM would significantly move the knowledge of Earth’s systems forward. The rest of this document describes the unique scientific opportunities available in TAM.
The Transantarctic Mountains – the world’s longest polar archive and unique modern natural laboratory
The scientific community working in the Transantarctic Mountains recognizes that our advances in disciplinary-focused investigations have paved the way for a new path toward multi-disciplinary efforts that will allow us to answer broad compelling questions which have emerged from our earlier efforts. Nowhere on Earth have so many important geologic features and fossils been discovered with so little time invested on the ground. Most finds on other continents reflect tens to hundreds of years of total scrutiny, whereas the total time to date spent on any one exposure in Antarctica can be measured in hours or days rather than in years. The ecosystems and the biological communities living in soil, ice, and lakes are largely unknown. Keeping in mind this disparity, it is amazing what investigations in TAM have already revealed about Antarctica’s physical and biological evolution, history, and current processes. We expect that TAM scientific investigations with a new multidisciplinary approach to answering the outstanding big questions will accelerate our understanding of this unique polar environment.
The research questions identified by the TAM science community span temporal scales from deep time to modern as well as localized to global spatial scales. These questions include:
1. How has the biogeochemical pathways been altered by both past life histories and current environmentally driven changes in the physiology and species composition of TAM biological communities?
- How have surficial process changed in response to climate over the past several million years and how has the biota responded to these changes?
- How have high-latitude ecosystems and biological communities evolved in the TAM over the past 350 Ma and how has landscape evolution through deep time affected ecosystem structure and stability?
- What are the geological and biological records of climate change in the TAM covering the past 350 Ma? How did the landscape evolve due to these climatic changes? What are the local and global atmospheric and oceanographic forcings, feedbacks, and thresholds that control the responses?
- How was Antarctica constructed over time and how has that affected landscape and biotic evolution?
- How have Antarctica’s global scale connections (such as plate tectonics, obliquity, atmospheric circulation, ocean currents) changed through time and how are they recorded in the Transantarctic Mountains?
While these questions are written with investigations in the Transantarctic Mountains in mind, our ability to address them is largely a function of the currently known and yet to be discovered records. The long-term (Archean-Mesozoic) record of Polar landscape (especially Paleozoic) and biotic evolution is preserved in the extensive exposures contained in TAM. The Cenozoic and recent glacial history is accessible in ice cores (~1 Myrs), glacial deposits (in some locations >10 Myrs), and deep sea sediments (60 Myrs). The Neogene-Quaternary glacial record is directly accessible in TAM where the buried ice, debris cover, glacial moraines, landforms and biological samples provide a comprehensive picture of recent environmental changes and related biological change.
Addressing the research questions outlined above requires a wide range of disciplines, which include: life-sciences, geology, glaciology, and atmospheric sciences. Such an approach to TAM studies would significantly expedite the science, as diverse groups would be studying in the same field area and exploring different increments of time. Such multidisciplinary research is known to facilitate innovation and be a productive incubator for the next generation of scientists.
The road map from past to future
The modern Antarctic environment was once assumed to be much like the seasonally frozen northern hemisphere, only without warm summers. Research has shown that this is true only in a superficial sense. The Arctic is characterized by seasonally melting ice in soil and snow on the ground surface. Antarctica is characterized by generally dry regolith with minimal amounts of melt water. This difference eliminates many of the typical permafrost related processes and landforms seen in the Arctic. Essentially, we have learned that the Antarctic environment is unique in that it is the product of prolonged cold desert conditions measured in millions of years. However, we have a poor understanding of how the environment changes over time scales of hundreds of thousands to millions of years. How does this uniqueness affect the life-forms that live in ice, water, and soil? How have the changes in climate and related glacial advances/retreats affected both the environment and the life forms?
The deposits dating to last few million years, although readily accessible at ice free areas, are just a short sliver in the landscape and biotic evolution of Antarctica. Deep time, including much of the Proterozoic (1750 to 542 Myrs) and Phanerozoic Eons (the last 542 Myrs), is also represented in the crystalline basement and sedimentary rocks exposed in TAM. This record contains information on environmental change as Antarctica split from the supercontinent of Rodinia, reassembled into the supercontinent of Gondwana, drifted into a polar position, and subsequently broke up into Earth’s modern lithospheric configuration.
Of particular interest is the late Paleozoic, Mesozoic and Cenozoic record. The late Paleozoic marks the last complete transition of an icehouse to a greenhouse/hothouse Earth (330 to 259 Ma). This transition led directly to Earth’s most severe extinction event, the end Permian mass extinction (at 252.6 Ma) when more than 90% of all marine species and 70% of terrestrial vertebrates became extinct. Restructuring of the biosphere ensued during the Triassic with an additional extinction event that severely affected the terrestrial biota at the end of the Triassic (201.3 Myrs ago). These extinction events fundamentally reorganized marine and terrestrial ecosystems, and in some cases can serve as analogues for understanding our modern biodiversity crisis. However, much of our knowledge of "global" extinction events is based on extrapolation from more heavily sampled temperate regions, begging the question: How have mass extinction events affected high-latitude ecosystems? During the Jurassic, a large igneous province developed in Gondwana, with the intrusion of extensive sills and dikes and the extrusion of large volumes of flood basalts, and profoundly influencing the TAM landscape, as well as probably affecting oceanic anoxia. Following a 256 Myr glacial hiatus, ice sheets returned to Antarctica ~34 Myrs ago marking the onset of Cenozoic glaciation, which continues today. During the Cenozoic, Antarctica’s biota continued to adapt and respond to environmental change. The sedimentary rocks and fossils in TAM record these changes and provide clues as to how Antarctica’s polar geosphere and biosphere responded to the environmental changes and evolved to its current state.
To address questions concerning deep time environmental evolution, investigations are needed by paleontologists to understand the ancient configuration of the biosphere and how the biota adapted to severe environmental change. Investigations by sedimentary geologists, igneous petrologists, and structural geologists are required to understand how the ancient landscape changed through time and what tectonic forces were acting on the Antarctic crustal blocks. Studies by paleopedologists and geochemists are needed to tease out the environmental signals and the record of chemical cycles from the rocks, and geochronologic studies are required to accurately determine the timing of events, and to integrate these into a complete picture of earth history.
Conclusion
The new focus of TAM research, to understand polar landscape and biotic evolution, would bring diverse scientists together to resolve how life and the environment have shifted with climate over the past 1725 Myrs, and specifically during the last 350 Myrs and how these uniquely Antarctic/South Polar processes are shaping today’s landscape. Although much can be learned about Earth systems through study of modern landscapes and organisms, a complete picture of how and why changes occur is only provided by understanding both modern and ancient environmental change. Thus, evolution of the Antarctic Polar system requires scientists addressing both modern and deep time environmental change. TAM rocks, fossils, landscapes, and the current biota provide the longest and most complete record of Polar conditions on Earth.
The new multidisciplinary research focus in Antarctica would provide an unprecedented view of the landscape and biota in a unique environment and provide detailed information on how landscapes and life on the continent have changed through time.
