OPP-0612493 Brachfield OPP-: 0612365 Polyak OPP-0612384 Ortiz OPP-0612473
Intellectual Merit: Understanding how the climate system functions and how it might change, especially in the climate-sensitive Arctic Ocean, is of paramount importance and could be achieved through high-resolution paleo-records. Until the Healy-Oden Trans-Arctic Expedition (HOTRAX'05), such records in the Arctic Ocean were very rare. HOTRAX not only recovered several high-resolution records from the Alaskan margin, but also plankton tows for isotopic calibration of foraminifer, and samples of porewater collected under hermetic conditions for calibration of important proxies such as pyrite and monosulfides as potential indicators of paleoproductivity. Many proxies will be measured in the research including: sediment reflectivity, biogenic components (foraminifer, dinocysts, etc.), nutrients, stable isotopes and cadmium/calcium and magnesium/calcium in foraminiferal tests, and iron oxide fingerprinting of ice rafted debris for sea ice sources and drift patterns. Age models and detailed core correlation will be of primary concern initially and involve several approaches including AMS carbon-14, paleomagnetics, and lead-210. The objective will be to establish paleoclimate records for the Holocene for the HOTRAX cores along the continental shelf margin north of Alaska in a critical zone for the confluence and impact of different water masses. These cores should be impacted by many of the important influxes that might affect or record climate change in the western Arctic Ocean, such as the Mackenzie River and other drainage systems, the Bering Strait influx of Pacific waters, and the sub-surface influx of North Atlantic Intermediate water. These cores are ideal for recording sea ice input events from Russian Shelves into the Beaufort Gyre presumably in response to fluctuations in the Arctic Oscillation. Therefore, several proxies will be employed to measure the important environmental and climatic changes that should be recorded in these very high resolution HOTRAX cores.
Broader Impacts: This research interfaces and fulfills many aspects of existing research initiatives such as the Study of Arctic environmental change (SEARCH), western Arctic Shelf-Basin Interactions (SBI), and paleoclimate component of the International Committee for Arctic Paleo Projects (ICARP) and its International Polar Year (IPY) affiliation. In addition, the results of this research could have important implications for residents of the north slope of Alaska with the focus on freshwater inputs and Russian ice to the waters offshore. Several graduate and undergraduate students will be involved. Many of the findings will be incorporated into courses taught by the investigators and talks to professional and community groups. More significantly, there will be opportunities for underrepresented minority students to participate and contribute to the proposed research through Old Dominion University's (ODU) Minority Undergraduate Scholarship and Training REU program (NSF-funded) and the joint ODU-Hampton University-Virginia Institute of Marine Sciences' Hall-Bonner Program for Minority Doctoral Scholars in Ocean Sciences (a NSF-funded Diversity in Geosciences grant). Collaboration with Teachers and Researchers Exploring and Collaborating (TREC) earth science teachers, begun on the HOTRAX cruise, will continue as part of this project with the development of small research exercises for the students that will be part of a website for use by similar teachers world-wide.
