Cosmogenic Be-10 data and calculated surface exposure ages from nunataks adjacent to Pine Island Glacier in the Hudson Mountains, West Antarctica

Samples (erratic cobbles perched on presently-exposed mountain peaks next to Pine Island Glacier) were collected by Dr Joanne S Johnson (British Antarctic Survey) during the 2019-20 austral summer. Latitude, altitude, and elevation measurements of the location of the samples were made using a Javad Triumph II GPS receiver. The sample heights above ellipsoid were corrected to orthometric heights (height above geoid EGM08 in metres above sea level) using Precise Point Positioning software. Laboratory chemistry was conducted in the CosmIC Laboratory at Imperial College London. Quartz purification followed the methods of Kohl and Nishiizumi (1992). Isotope dilution chemistry and beryllium purification used the methods of Corbett et al. (2016). Be-10/Be-9 ratios were measured by accelerator mass spectrometry at ANSTO using the methods of Wilcken et al. (2017) and normalized to the standard values of Nishiizumi et al. (2007). Laboratory data were then converted to Be-10 concentrations and, finally, exposure ages using an online exposure age calculator (Balco et al., 2008). Exposure ages were calculated using the default global production rate and two different cosmogenic nuclide scaling methods (known as St and LSDn).