Glacial Geologic Investigation of Upper Rennick Glacier Region, Northern Victoria Land

The 1974-1975 field season was spent investigating the upper Rennick Glacier area (figure) for (1) the relationship between the glacial history of the study area and the glacial histories already defined for more southerly sectors of the Transantarctic Mountains, (2) the history and dimensions of former fluctuations of the east antarctic ice sheet, Rennick Glacier, and its tributaries, as recorded in glacial deposits, and (3) the significance of this area in paleoclimatic reconstructions of Antarctica and the world

Detailed Glaciochemical Investigations in Southern Victoria Land, Antarctica — A Proxy Climate Record

The production of environmental change records using time-series data retrieved from ice cores has seen minimal application in the Transantarctic Mountains despite the existence of a well-developed lower resolution glacial geologic record for this area which forms the primary basis for understanding the glacial history of East Antarctica. In addition, records derived from marine and lake cores, glacier margin fluctuation studies, measures of volcanic activity, and meteorological data sets from within or close to the Transantarctic Mountains are available for comparison. This emerging environmental data-base provides the tools needed to define the change characteristics, over a period of thousands of years, of several major dynamic components in this region, e.g., climate, atmospheric chemistry, sea-ice extent, volcanic activity, and atmospheric turbidity

Antarctic Oversnow Traverse-based Southern Hemisphere Climate Reconstruction

On 2 January 2003, the U.S. component of the International Trans Antarctic Scientific Expedition (U.S. ITASE) (Figure 1) arrived at the South Pole after completing more than 5000 km of oversnow traverses that included much of west Antarctica and a portion of east Antarctica (Figure 2). During the traverses, which were performed from 1999 through 2003, U.S. ITASE focused on collecting data that will allow the reconstruction of sub-annual scale climate variability and changes in the chemistry of the atmosphere over the last 200+ years. ITASE is a multi-disciplinary research program supported by 19 nations and endorsed by the Scientific Committee on Antarctic Research (SCAR) and the International Geosphere-Biosphere Program (IGBP) [Mayewski and Goodwin, 1997]. It is designed to reconstruct the recent climate history of Antarctica through ice coring and related observations along a network of extensive intra-continental traverses. The U.S. component of ITASE is supported by the Office of Polar Programs of the National Science Foundation. It includes scientific projects from the following institutions: Cold Regions Research and Engineering Laboratory-U.S. Army, Desert Research Institute, NASA, Ohio State University, St. Olaf College, the University of Arizona, the University of Colorado, the University of Maine, and the University of Washington. Information concerning climate variability in the middle and high latitudes of the southern hemisphere is obtained by U.S. ITASE, through calibrations developed between US. ITASE ice core records and direct atmospheric observations [Kreutz et al., 2000; Meyerson et al., 2002; Schneider and Steig, 2002]

Ice Mass Fluctuations in NorthernVictoria Land

[From the introduction] Rennick Glacier is one of the major ice drainages for the northern Victoria Land sector of East Antarctica. Unlike glaciers farther south along the Transantarctic Mountains, Rennick Glacier does not drain into the Ross Ice Shelf but flows directly into a seasonally ice-covered ocean. Therefore, current fluctuations of this glacier are unhampered by the dampening effects of the Ross Ice Shelf. The primary controls on the activity of this glacier and others in this region are mass balance and sea level

Ice Cores and Global Change

For scientists interested in global change problems, ice core records provide a unique and invaluable medium for studying the past. These records yield both direct and proxy links to the paleoenvironment over periods potentially as long as hundreds of thousands of years with resolution down to seasonal scale for time-series on the order of hundreds to thousands of years. In addition, the fact that most ice core records are retrieved from locations rarely, if ever, occupied by observers, adds to the value of these data sets. In response to the growing importance of such records, the National Science Foundation\u27s Division of Polar Programs recently sponsored the U.S. Ice Core Research Workshop in Durham, N.H. At the workshop, 45 U.S. scientists actively involved in ice core research together formulated a globally based strategy planned through the 1990s that would result in the development of an ice core program integrally tied to global change issues. Representatives from the European ice core research community also attended, to aid in discussions of anticipated joint international efforts

Glaciology and Glacio-geomorphology in Victoria Landand Queen Maud Mountains

During the past year, data analysis has been under-taken on the recent and past dynamics of several northern Victoria Land glaciers, notably Rennick Glacier; the dynamics of selected rock glaciers in Wright Valley; and on the weathering characteristics of dolorites in the Queen Maud Mountains

Transantarctic Mountains Ice Core Study

Several sites within the Transantarctic Mountains fit the requirements necessary for the retrieval of ice cores that can provide valuable information concerning climate change and atmospheric chemistry

Weathering Stages of a Tholeiitic Basalt (Dolerite), Queen Maud Mountains

The sparsity of datable material and key horizons throughout most of the Transantarctic Mountains requires that much of the mapping and correlation of glacial deposits, especially moraines, be based primarily on qualitative techniques. One qualitative method is to characterize the degree of weathering of clasts covering these deposits (Behling, 1971; Calkin, 1971; Nichols, 1971; and Mayewski, 1975). Lacking, however, is a detailed understanding of the role and method of weathering. To help solve this problem, soil studies have been made by Claridge and Campbell (1968) in the Shackleton Glacier region and Everett and Behling (1968), Linkletter (1972), Behling (1971), and Everett (1971) in the dry valleys of southern Victoria Land. Studies on individual lithologies (see,for example, Kelly and Zumberge, 1961) demonstrate the need for more sharply delimited studies,and we are examining a weathering suite of tholeiitic basalts (dolerites) from a site in the Queen Maud Mountains

Glacial Geology Near McMurdo Sound and Comparison with the Central Transantarctic Mountains

(From summary, pp. 105-106) In the central Transantarctic Mountains, the Sirius Formation consists of both a lower massive till and an upper assemblage of interlayered till and stratified lenses. Deposits of the Sirius Formation found in the McMurdo region contain only the lower massive till. The lower massive till of the Sirius Formation is thought to be a basal till because of extremely strong fabric, high concentration of faceted and striated pebbles, and heterogeneous particle sizes (clay to boulders). Fabrics observed in the basal till indicate that the ice that deposited the Sirius Formation, although displaying a much higher surface than the present ice, flowed in the same direction the present ice does. The broad expanse of depositional sites (Scott Glacier to the Coombs Hills) and the fabrics imply that the Sirius Formation was deposited by a continental-scale ice sheet. Moreover, to deposit a basal till the ice related to the Sirius Formation must have been not only of a continental scale but thick enough to permit basal melting

The Dominion Range Ice Core

Localized-accumulation basins in the Transantarctic Mountains contain sites yielding ice-cores that provide highly detailed (seasonal to annual resolution, depending upon depth),several-thousand-year records of glacial history, climatic change, volcanic activity, and atmospheric chemistry. The scientific attraction of these sites, first, their geographic location with respect to other ice-core studies (which are most commonly recovered from inland sectors of the antarctic ice sheet)and second, the fact that Transantarctic Mountain sites are more directly comparable to glacial geologic records because the latter are usually based on studies in these mountains. Although the ice-core records from these sites cover shorter periods than glacial geologic records, they provide much finer resolution and hence allow more elaborate and direct comparisons to be made with modern Antarctica. Details gained from ice-core records in the Transantarctic Mountains, therefore, provide us with a better understanding of glacial geologic records. The most valuable ice-core records are those which are highly detailed and involve a number of different types of physical and chemical measurements because such records maximize the dating of the core while also providing the tightest resolution and interpretation