Well, we are almost off on our next big adventure. Here’s our very official-sounding description of what we’re going to be up to.
On January 29, 2014, two University of South Florida College of Marine Science faculty members, Dr. Eugene Domack and Dr. Amelia Shevenell, and three graduate students, Ms. Michelle Guitard, Ms. Katie Smith, and Ms. Tasha Snow, will board the United States Antarctic Program research icebreaker Nathanial B. Palmer in Hobart, Tasmania and embark on an oceanographic research expedition to the remote Totten Glacier, East Antarctica.
The USF team is part of a multidisciplinary group of earth scientists from Colgate University, Columbia University, Macquarie University, Texas A&M, University of Tasmania, University of Texas, and Geoscience Australia. The team will spend 46 days collecting oceanographic and geologic data to better understand the coupling of ocean and ice in one of the most remote and climatically sensitive regions in Antarctica.
Totten Glacier is the termination of the largest marine-based portion of the East Antarctic Ice Sheet, yet surprisingly little is known about its stability. Due its remote location and heavy sea ice, the continental shelf in front of the Totten Glacier has never been comprehensively surveyed. In fact, much more is known about the bedrock topography underneath Antarctica’s vast ice sheets than about the depth of the ocean floor in this region.
Recent satellite observations indicate that the Totten ice drainage system is thinning in response to undermelting by intruding warm ocean waters. While this process is observed elsewhere in Antarctica (e.g. the rapidly retreating Pine Island Glacier in West Antarctica), the Totten Glacier system is potentially Antarctica’s most important glacial drainage system due to its large size; it is three times larger than any system in West Antarctica. Thus, the system could transfer large volumes of glacial meltwater to the oceans at faster rates than any other marine based ice system on Earth. Sparse regional oceanographic data supports warm water intrusion, but no sampling has ever been conducted in front of the Totten Glacier, where warm water could impact the mass balance of the glacier system most directly. For these reasons the NSF has elevated this project to one of its top priorities, for this austral field season.
During the expedition, USF researchers will generate detailed bathymetric maps of the seafloor to improve understanding of ice and ocean coupling as well as regional navigation. The team will also collect 25-meter long marine sediment cores from the continental shelf using the N. B. Palmer’s jumbo piston corer. These cores will allow researchers to reconstruct past periods of instability of the Totten Glacier system in order to evaluate what forces the system to retreat and advance.
Although the focus of the research cruise is the Totten Glacier system, the USF team will also conduct dredging operations near Mertz Glacier, east of Totten Glacier. 2014 marks the centenary of Australian explorer Douglas Mawson’s famous Australasian Antarctic Expedition. During this expedition, Mawson collected unusual sedimentary rocks from the seafloor near Mertz Glacier. These lignites (brown coal) suggested a period of climatic warmth prior to the initiation of Antarctic glaciation in the late Eocene, approximately 35 million years ago. Mawson’s samples were lost sometime after 1920 and their age and character remain unknown.
The USF team hopes to conduct a comprehensive series of dredges in this same region to recover the lignites and assist in planning for a future International Ocean Discover Program (IODP) drilling expedition to the Wilkes Land margin.
This is not the first time that the USF team has worked together in Antarctica. Domack and Shevenell have worked together since 1992. In 2012, Domack, Shevenell, and Smith conducted paleoclimate research west of the Antarctic Peninsula on the USAP research vessel Laurence M. Gould. In late 2013, Shevenell lead a similar expedition, assisted by her graduate students, Guitard and Snow.