Bayesian inversion of a CRN depth profile to infer Quaternary erosion of the northwestern Campine Plateau (NE Belgium)
Bayesian inversion of a CRN depth profile to infer Quaternary erosion of the northwestern Campine Plateau (NE Belgium)
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CRN 深度剖面的贝叶斯反演可推断坎平高原西北部（比利时东北部）的第四纪侵蚀
DOI：
10.5194/esurf-5-331-2017
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发表时间：
2017
影响因子：
5.2
通讯作者：
L. Wouters
中科院分区：
文献类型：
--
作者：
E. Laloy;K. Beerten;V. Vanacker;M. Christl;B. Rogiers;L. Wouters
抽象的。坎皮恩高原（比利时东北部）等温带地区低洼沙地在第四纪期间的侵蚀速度存在争议。目前对坎平地区景观演化平均速度的了解主要基于地质推论和现代类比。我们对原位产生的 10Be 浓度深度剖面进行贝叶斯反演，以推断平均长期侵蚀率以及其他两个参数：表面暴露年龄和继承的 10Be 浓度。与宇宙成因放射性核素 (CRN) 数据概率反演的最新进展相比，我们的方法具有以下两个创新部分：(1) 使用马尔可夫链蒙特卡罗 (MCMC) 采样；(2) 考虑（在某些假设下）模型误差对后验不确定性的贡献。为了研究我们的方法与实践中现有技术的不同程度，我们与 CRONUScalc 程序中实现的贝叶斯反演方法进行了比较。两种方法都识别出相似的最大后验 (MAP) 参数值，但使用 CRONUScalc 中采用的方法导出的后验参数和预测不确定性被适度低估。因此，建议在存在模型误差的情况下使用类似 CRONUScalc 的方法产生更一致的不确定性估计的简单方法。与世界其他地方类似（古）气候下侵蚀的地貌相比，我们推断的侵蚀率为 39 ± 8. 9mmkyr−1 (1σ)，相对较大。我们根据基质的侵蚀性和中更新世期间基准面的突然降低来评估该值。双核素浓度深度剖面的更密集采样方案将允许更好的推断侵蚀率分辨率，并在 MCMC 反演中包含更多不确定参数。
Abstract. The rate at which low-lying sandy areas in temperate regions, such as the Campine Plateau (NE Belgium), have been eroding during the Quaternary is a matter of debate. Current knowledge on the average pace of landscape evolution in the Campine area is largely based on geological inferences and modern analogies. We performed a Bayesian inversion of an in situ-produced 10Be concentration depth profile to infer the average long-term erosion rate together with two other parameters: the surface exposure age and the inherited 10Be concentration. Compared to the latest advances in probabilistic inversion of cosmogenic radionuclide (CRN) data, our approach has the following two innovative components: it (1) uses Markov chain Monte Carlo (MCMC) sampling and (2) accounts (under certain assumptions) for the contribution of model errors to posterior uncertainty. To investigate to what extent our approach differs from the state of the art in practice, a comparison against the Bayesian inversion method implemented in the CRONUScalc program is made. Both approaches identify similar maximum a posteriori (MAP) parameter values, but posterior parameter and predictive uncertainty derived using the method taken in CRONUScalc is moderately underestimated. A simple way for producing more consistent uncertainty estimates with the CRONUScalc-like method in the presence of model errors is therefore suggested. Our inferred erosion rate of 39 ± 8. 9 mm kyr−1 (1σ) is relatively large in comparison with landforms that erode under comparable (paleo-)climates elsewhere in the world. We evaluate this value in the light of the erodibility of the substrate and sudden base level lowering during the Middle Pleistocene. A denser sampling scheme of a two-nuclide concentration depth profile would allow for better inferred erosion rate resolution, and including more uncertain parameters in the MCMC inversion.
影响因子：
2.7
作者：
Marrero, Shasta M.;Phillips, Fred M.;Balco, Greg
通讯作者：
Balco, Greg