Paper No. 9
Presentation Time: 3:20 PM
BAYESIAN ANALYSIS OF PAIRED IN SITU 14C AND 10BE MEASUREMENTS: INSIGHTS INTO COMPLEX EXPOSURE HISTORIES
Studies employing measurements of two or more in situ cosmogenic nuclides are powerful approaches to addressing geomorphic questions, such as complex exposure histories or burial dating. A key emerging application in this regard uses paired in situ 14C-10Be measurements from proglacial bedrock to constrain both (1) the waxing and waning of glaciers and ice sheets during the Holocene Epoch, and (2) the present subglacial dynamics (e.g., abrasion rates). By combining a well-posed geomorphic model with Bayesian analysis, we can uniquely solve for the exposure duration, burial duration, and distribution of glacial abrasion rates across a glacial trough. While Bayesian analysis is a recent advance in the interpretation of these and other datasets, precise measurement of 14C and 10Be, sometimes at very low concentrations is perhaps the most critical requirement for success. We will discuss the use of Bayesian analysis in cosmogenic nuclides studies, both in our particular project and more generally, as well as advances in 14C and 10Be measurements.