부산대학교 도서관

Previously developed software packages that generate probabilistic age models for ocean sediment cores are designed to either interpolate between different age proxies at discrete depths (e.g., radiocarbon, tephra layers, or tie points) or perform a probabilistic stratigraphic alignment to a dated target (e.g., of benthic [delta].sup.18 O) and cannot combine age inferences from both techniques. Furthermore, many radiocarbon dating packages are not specifically designed for marine sediment cores, and the default settings may not accurately reflect the probability of sedimentation rate variability in the deep ocean, thus requiring subjective tuning of the parameter settings. Here we present a new technique for generating Bayesian age models and stacks using ocean sediment core radiocarbon and probabilistic alignment of benthic [delta].sup.18 O data, implemented in a software package named BIGMACS (Bayesian Inference Gaussian Process regression and Multiproxy Alignment of Continuous Signals). BIGMACS constructs multiproxy age models by combining age inferences from both radiocarbon ages and probabilistic benthic [delta].sup.18 O stratigraphic alignment and constrains sedimentation rates using an empirically derived prior model based on 37 .sup.14 C-dated ocean sediment cores (Lin et al., 2014). BIGMACS also constructs continuous benthic [delta].sup.18 O stacks via a Gaussian process regression, which requires a smaller number of cores than previous stacking methods. This feature allows users to construct stacks for a region that shares a homogeneous deep-water [delta].sup.18 O signal, while leveraging radiocarbon dates across multiple cores. Thus, BIGMACS efficiently generates local or regional stacks with smaller uncertainties in both age and [delta].sup.18 O than previously available techniques. We present two example regional benthic [delta].sup.18 O stacks and demonstrate that the multiproxy age models produced by BIGMACS are more precise than their single-proxy counterparts.
Byline: Taehee Lee, Devin Rand, Lorraine E. Lisiecki, Geoffrey Gebbie, Charles Lawrence To access, purchase, authenticate, or subscribe to the full-text of this article, please visit this link: https://cp.copernicus.org/articles/19/1993/2023/cp-19-1993-2023.html, or [...]