...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Paleoceanography >Probabilistic sequence alignment of stratigraphic records
【24h】

Probabilistic sequence alignment of stratigraphic records

机译：地层记录的概率序列比对

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The assessment of age uncertainty in stratigraphically aligned records is a pressing need in paleoceanographic research. The alignment of ocean sediment cores is used to develop mutually consistent age models for climate proxies and is often based on the δ~(18)O of calcite from benthic foraminifera, which records a global ice volume and deep water temperature signal. To date, δ~(18)O alignment has been performed by manual, qualitative comparison or by deterministic algorithms. Here we present a hidden Markov model (HMM) probabilistic algorithm to find 95% confidence bands for δ~(18)O alignment. This model considers the probability of every possible alignment based on its fit to the δ~(18)O data and transition probabilities for sedimentation rate changes obtained from radiocarbon-based estimates for 37 cores. Uncertainty is assessed using a stochastic back trace recursion to sample alignments in exact proportion to their probability.We applied the algorithm to align 35 late Pleistocene records to a global benthic δ~(18)O stack and found that themean width of 95% confidence intervals varies between 3 and 23 kyr depending on the resolution and noisiness of the record's δ~(18)O signal. Confidence bands within individual cores also vary greatly, ranging from ~0 to >40 kyr. These alignment uncertainty estimates will allow researchers to examine the robustness of their conclusions, including the statistical evaluation of lead-lag relationships between events observed in different cores.
机译：地层学记录中年龄不确定性的评估是古海洋学研究的迫切需求。海洋沉积物芯线的对准用于建立气候代理的相互一致的年龄模型，并且通常基于底栖有孔虫的方解石的δ〜（18）O，记录了全球冰量和深水温度信号。迄今为止，已经通过手工，定性比较或确定性算法进行了δ〜（18）O的比对。在这里，我们提出了一种隐马尔可夫模型（HMM）概率算法，以找到δ〜（18）O对准的95％置信带。该模型基于对δ〜（18）O数据的拟合以及从基于37个岩心的基于放射性碳的估计值得出的沉积速率变化的过渡概率，来考虑每种可能的对准的可能性。使用随机回溯递归以与概率成正比的方式对样本比对进行不确定性评估，我们应用该算法将35个更新世晚期记录与全球底栖δ〜（18）O层比对，发现主题宽度为95％置信区间根据记录的δ〜（18）O信号的分辨率和噪声，在3至23 kyr之间变化。各个核心的置信区间也相差很大，范围从〜0到> 40 kyr。这些一致性不确定性估计值将使研究人员能够检查其结论的稳健性，包括对在不同核心中观察到的事件之间的超前-滞后关系进行统计评估。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号