Enhancing Holocene Ice Sheet and Ice Shelf Geochronology using Geomagnetic Paleointensity Variations

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The project aims on constructing a geomagnetic relative paleointensity (RPI) and paleosecular variation (PSV) record from Maxwell Bay, South Shetland Islands, using the Shallow Drilling (SHALDRIL) 108-m core that was collected in 2005 during the cruise of the USAP research ship Nathaniel B. Palmer. This core has the unique combination of a radiocarbon chronology constructed entirely from biogenic calcite dates and a homogeneous silty-clay lithology that is ideal for paleomagnetic studies. This combination is rarely found in Antarctic continental shelf sediments. The RPI and PSV records from the Maxwell Bay core will serve as regional reference curves for tuning and dating records of ice sheet, ice shelf, and glacier history on both sides of the northern Antarctic Peninsula that lack their own independent age control. The use of paleointensity curves for millennial-scale correlation and dating via tuning with a reference curve has been successfully applied around the globe, and could provide a much-needed additional geochronology tool for the Antarctic. As one of the very few independently dated RPI and PSV records from high southern latitudes, this record will also be valuable for inclusion in geomagnetic field models that seek to understand the time-varying behavior of the geodynamo. The PSV and RPI datasets will be made publicly available through the Magnetics Information Consortium (MagIC) paleomagnetic database.