Expedition Search

Antarctica plays a central role in global tectonic evolution. Competing theories have been put forward to explain the formation of the Transantarctic Mountains (TAMs) and the Wilkes Subglacial Basin (WSB), primarily due to a lack of information on the crustal thickness and seismic velocity of these areas. The research team is attempting to resolve how the TAMs and WSB originated and how their formation relates to Antarctica's geologic history. Since most of Antarctica is covered by large ice sheets, direct geologic observations cannot be made; therefore, "remote sensing" methods like seismology must be used to determine details about the earth structure.

The goal of this project, funded by the National Science Foundation, is to broaden our knowledge of the geology in this region with a new seismic array; the Transantarctic Mountains Northern Network (TAMNNET), a 15-station array across the northern TAMs and the WSB that helps fill a major gap in seismic coverage. Data from TAMNNET is being combined with that from previous and ongoing seismic initiatives and is analyzed to generate an image of the seismic structure beneath the TAMs and the WSB.

While in the field, the team spent most of their time servicing the seismic stations that compose the new TAMNNET array. This included loading equipment onto small airplanes, flying to remote field locations, uncovering the deployed equipment, and checking for any maintenance issues. The first batch of data from the network was also retrieved during this time.

The oldest fossil life on Earth consists of stromatolites, which are the remains of complicated communities of bacteria captured in rock. On modern Earth, similar communities still grow in places that are too harsh for worms, snails, and other grazing animals to live and eat them. Lakes in Antarctica with liquid water below a few meters of ice almost always support these communities. Thus, they provide the opportunity to study the ecology of microbial communities like those on early Earth billions of years ago.

The research team studied the communities in Lake Joyce, Antarctica in several different ways. They took images of the stromatolites in Lake Joyce and reconstructed the 3D morphology of microbial mats in the lake. They also characterized the environment that the stromatolites are growing in and studied how the morphology of the stromatolites varies mud deposition and calcite mineral formation. They also directly sampled the stromatolites to study the distribution of photosynthesis, calcite mineral formation, and mud incorporation.

They expect this study to make several important contributions to understanding early life on Earth. Morphological studies of the stromatolites will provide insights into how microbial communities build intricate structures and how variations in environment and ecology affect morphology. Results will also help researchers understand how microbial communities influence calcite mineral growth and how this affects stromatolite morphology. Results will be directly applicable to better interpreting ancient stromatolites, providing insights into ecological and biogeochemical processes on early Earth. Finally, a better understanding of the processes by which microbial communities build stromatolites will aid in the search for evidence of life on other planets, such as Mars, where landed missions have access to sedimentary rocks.

If the Antarctic ice sheet were to collapse or melt substantially it would impact all of humankind. This research attempts to reconstruct the paleogeography of parts of Antarctica while trying to determine the physical conditions that led to formation of the Antarctic ice sheet.

The past opening of deep Southern Ocean gateways between Antarctica and South America and between Antarctica and Australia permitted the complete circulation of the Antarctic Circumpolar Current (ACC). This opening may have been critical in the transition from a warm Earth in the past, to the subsequently much cooler conditions that persist to the present day. The opening of Drake Passage and the West Scotia Sea probably broke the final barrier formed by the Andes of Tierra del Fuego and the 'Antarctandes' of the Antarctic Peninsula. It is thought that once this deep gateway, usually referred to simply as the Drake Passage gateway (DPG), was created, the strong and persistent mid-latitude winds likely generated one of the largest deep currents on Earth. This event is widely believed to be closely associated in time with a major, abrupt drop in global temperatures and the rapid expansion of the Antarctic ice sheets 33-34 million years ago. On an earlier cruise to the Central Scotia Sea on board Nathaniel B. Palmer, however, Dalziel and Lawver and their colleagues found evidence that there may have been a barrier to eastward flow from Drake Passage to the South Atlantic Ocean basin until 10-12 million years ago when the planet descended even more deeply into an 'icehouse' state.

The research team dredged seafloor samples and analyzed them for their age and composition to determine if they may indeed have once blocked the Antarctic Circumpolar Current. They mapped the sub-seafloor to see how and/or if South Georgia is colliding with the North East Georgia Rise and with their co-investigator Robert Smalley of the University of Memphis they installed three GPS units on South Georgia to determine its horizontal and vertical motion. It is notable that the mountains of the island, which the explorer Ernest Shackleton and his companions had to cross after their celebrated small boat journey from Antarctica, are three times as high as the equivalent part of the Andean Cordillera in Tierra del Fuego.

The retreat of glaciers is one of the most profound visual signs of global warming. Identifying the current magnitude of glacier retreat and its significance in the longer-term context of glacier history encourages a deeper understanding of what it means for society. The goal of this project was to provide a longer-term context for current climate warming and to better define the nature of abrupt climate changes over the past 5000 years in the Arctic.

The research team applied complimentary techniques to both the preserved plants and rocks exposed at the foot of retreating glaciers in West Greenland. Radiocarbon-dating techniques were applied to the plants and the isotopic signature of recently exposed rock surfaces were determined, allowing researchers to determine the duration of ice-covered and ice-free conditions throughout the Holocene (the past 11,700 years since the end of the last major ice age). Combined, these two datasets explicitly date when the region was last as warm as present. Comparing climate reconstructions with on-going studies elsewhere will help to further define recent abrupt climate changes.

The research team worked out of Barrow, Alaska, at the juxtaposition of two Arctic seas; the Chukchi and Beaufort Seas. It is a region frequently traveled by the endangered bowhead whale. This project had its genesis in understanding why the region near Barrow, Alaska is a feeding hotspot for migrating bowhead whales, and the whales and their prey will continue to be a focus of the team's interpretations. The research team conducted oceanographic sampling of the physical and biological marine environment in the region over the period 2005-2011 and observed significant inter-annual variability. Long-term studies of the ocean conditions in the Arctic are needed in order to understand how these environments vary inter-annually. The research team will continue to document conditions in the biological-physical ocean ecosystem, through annual boat-based surveys in order to predict and understand potential impacts of climate change on the Arctic ecosystem.

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Titulo financiado: Observación anual del medio ambiente marino biológico y físico en los mares Chukchi y Beauford en las cercanías de Barrow, AK.

El equipo de investigación viajará por avión a Barrow, una comunidad pequeña de aproximadamente 4,500 habitantes en la costa norte de Alaska. Como permitan las condiciones del tiempo, el equipo se embarcara para la colección de muestras oceanográficas a bordo del buque de investigación Annika Marie de 43 pies. Las actividades de a bordo incluirán colección de agua y plancton y mediciones de conductividad, temperatura, y profundidad. A bordo también tomarán nota sobre las ocurrencias de mamíferos marinos y realizarán el procesamiento preliminar de muestras. Si el clima es malo para navegar en el océano ellos pasarán el tiempo en Barrow catalogando muestras y organizándose para los días que pasaran sobre el agua.

The Svalbard Archipelago has an arctic climate and is home to several large bodies of ice— alpine glaciers in the mountains, and tidewater glaciers that descend into the sea. For the past 10,000 years the glaciers of this region have been receding and more recently researchers have noted a regional reduction in sea ice.

The research team, which includes undergraduate geoscience students participating in the Research Experiences Undergraduates (REU) Program, traveled to Svalbard to research how high latitude glaciers, melt-water streams, and sedimentation in the fjords reflect climate. The Svalbard region is ideal for the study of past climate because several different types of measurements on and around glaciers can be conducted there. Working out of small boats in the fiord and hiking to sites on land, the team collected data to determine what relationships exist between current sedimentation, glaciers, oceans, and climate. Using the historic sedimentation record can help the researchers understand and better predict how glacial systems react to climate change.

Applied Research in Environmental Sciences Nonprofit, Inc., ARIES, the Barrow Arctic Science Consortium, BASC, the North Slope Borough of Risk Management, and Cooperative Extension of Ilisgavik College are collaborating to plan, develop and implement a historical ecology model for the North Slope Coastal Region of Alaska. Historical ecology is an applied research program that focuses on interactions of people and their environments. Research applications involve studying and understanding this relationship in both time and space to gain a full picture of all of its accumulated effects. The research program can be applied to understanding changes among community landscapes that can assist strategies for the future. For this proposal the emphases align with the ARIES mission of research, education and community engagement, the Inupiaq Learning Framework of the North Slope School District, and the eco-heritage indicator of the CRIOS model (Cumulative Regional Integrated Operability Scores). Read more at the project website here.

The project emphases are 1) a bibliographic database of relevant historical resources, 2) an examination of the shoreline to provide a long time-series baseline, 3) simulation models to demonstrate socio-natural cycles of change for the North Slope shoreline, 4) the historical ecology study of the shoreline, interactive mapping and database available as a web based resource to assist academia, industry, regional government and local communities for socio-natural risk management (e.g., Barrow Area Information Database, 5) an integrated team of researchers, corporations, community planners, and Risk Management of the North Slope Borough to extract data and provide simulation models that apply to current studies and hazards of the region, especially mitigation tools for community decisions, and 6) provide a variety of eco-heritage opportunities that include community participation in research, educational products, age level appropriate activities and outreaches for community service learning, such as Teen CERT for the Next Generations and PolarTREC.

The expedition members visited several research sites in Greenland as part of an initiative to foster enhanced international scientific cooperation between the countries. The expedition members spent several days learning about the research conducted in Greenland, the logistics involved in supporting the research, and gained first-hand experience conducting experiments and developing inquiry-based educational activities.

This year's work builds on past expeditions and is supported by the National Science Foundation. The project was developed through cooperation with the U.S.-Denmark-Greenland Joint Committee, which was established in 2004 to broaden and deepen cooperation among the United States, the Kingdom of Denmark, and Greenland.

The program has two components
Kangerlussuaq Science Field School and Science Education Week

Microbial diversity has recently been found to show a pattern of organization at various scales. The research team attempts to answer three basic questions about microbial diversity and dispersal, focused on the long-term aspects of dispersal events and climate change: 1) How does environment influence microbial community composition and rate of function? For example, how quickly they convert organic material to carbon dioxide. 2) How are distribution patterns of microbial communities in lakes, streams, and soils influenced by the dispersal from local water flow? 3) How are the shifts in microbial community composition related to shifts in environmental conditions over time such as those caused by climate change?

To date, the researchers have found that microbial communities in lakes and rivers change dramatically through the seasons but reassemble on an annual basis. They have also found that community composition in soil and surface waters shifts within days in response to environmental fluctuations in temperature or dissolved organic matter composition. They have also found that upland terrestrial habitats act as landscape-level seedbanks for lowland aquatic systems. The ultimate goal of the project is to develop a greater understanding of the controls on microbial community composition and function over space and time.

Tremendous stores of organic carbon frozen in permafrost soils have the potential to greatly increase the amount of carbon in the atmosphere. Permafrost soils may thaw sporadically and melting ground ice can cause land-surface sinking called "thermokarst failures". These failures change the rate and amount of carbon released with the unanticipated outcome being that soil carbon can be mixed-up from a depth and exposed to sunlight as the land surface is altered. Sunlight can photo-degrade or break-down organic carbon and alter the carbon's ability to support bacterial respiration to produce carbon dioxide. Whether sunlight and UV exposure will enhance or retard the conversion of newly exposed carbon to carbon dioxide is currently unknown—this study is providing the first evidence that this alteration will be amplified by photochemical processes and their effects on microbes.

The research team is trying to understand exactly how sunlight and bacteria degrade dissolved organic matter by determining how fast these processes convert newly released dissolved organic matter to carbon dioxide, compared to dissolved organic matter already in surface waters. The team is accomplishing their research objectives with a series of laboratory experiments to determine rates of photodegradation and microbial processing of dissolved organic matter from different sources, and a series of landscape comparisons and sampling transects to characterize dissolved organic matter degradation in small basins and large rivers extending from the headwaters to the Arctic Ocean. Ultimately, this research will attempt to answer questions such as whether carbon export from tundra to oceans will rise or fall and how reactive the exported carbon will be. The team hopes to be able to measure the ultimate impact of impending disturbances, including climate change, on the net carbon balance of the Arctic and its interaction with the global carbon cycle.