Relative sea-level change in Newfoundland, Canada during the past ∼3000 years
Relative sea-level change in Newfoundland, Canada during the past ∼3000 years
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DOI：
10.1016/j.quascirev.2018.10.012
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发表时间：
2018-12
影响因子：
4
通讯作者：
A. Kemp;A. Wright;R. Edwards;R. Barnett;M. Brain;Robert E Kopp;N. Cahill;B. Horton;D. Charman;A. Hawkes;T. Hill;O. van de Plassche
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文献类型：
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作者：
A. Kemp;A. Wright;R. Edwards;R. Barnett;M. Brain;Robert E Kopp;N. Cahill;B. Horton;D. Charman;A. Hawkes;T. Hill;O. van de Plassche
几个过程有助于沿海相对海平面（RSL）的变化，在北大西洋观测和/或预测有不同的空间表达，随纬度而变化。为了扩大纬度范围的RSL记录跨越过去103000年和识别这些过程的特征指纹的可能性，我们重建RSL在两个网站（大河和Placentia）在纽芬兰盐沼沉积物。贝叶斯传递函数建立了前海平面的高度保存组合有孔虫和有壳变形虫。受放射性碳测年和年代范围限制的水深模型估计了沉积物沉积的时间。在过去的103000年里，大河的RSL上升了103.0米，普拉森西亚上升了101.5米。当地校准的岩土模型表明，沉积后降低通过沉积物压实是最小的。为了隔离和量化全球，区域线性，区域非线性和局部尺度过程对RSL的贡献，我们使用时空统计模型分解了新的重建（以及扩展的全球数据库中的重建）。全球部分证实，20世纪海平面上升发生在3000多年来最快的世纪尺度的速度（P > 0.999）。区分本地和区域的非线性过程的贡献是具有挑战性的稀疏网络的重建。然而，只有一个小的贡献，从本地规模的过程是必要的RSL重建和建模RSL的趋势。我们确定了三个纬度组织的网站，共享一致的区域非线性趋势，并表明海洋质量的动态重新分配的电流和/或风可能是海平面变化的重要驱动力在北大西洋在过去的10000年。
Several processes contributing to coastal relative sea-level (RSL) change in the North Atlantic Ocean are observed and/or predicted to have distinctive spatial expressions that vary by latitude. To expand the latitudinal range of RSL records spanning the past ∼3000 years and the likelihood of recognizing the characteristic fingerprints of these processes, we reconstructed RSL at two sites (Big River and Placentia) in Newfoundland from salt-marsh sediment. Bayesian transfer functions established the height of former sea level from preserved assemblages of foraminifera and testate amoebae. Age-depth models constrained by radiocarbon dates and chronohorizons estimated the timing of sediment deposition. During the past ∼3000 years, RSL rose by ∼3.0 m at Big River and by ∼1.5 m at Placentia. A locally calibrated geotechnical model showed that post-depositional lowering through sediment compaction was minimal. To isolate and quantify contributions to RSL from global, regional linear, regional non-linear, and local-scale processes, we decomposed the new reconstructions (and those in an expanded, global database) using a spatio-temporal statistical model. The global component confirms that 20th century sea-level rise occurred at the fastest, century-scale rate in over 3000 years (P > 0.999). Distinguishing the contributions from local and regional non-linear processes is made challenging by a sparse network of reconstructions. However, only a small contribution from local-scale processes is necessary to reconcile RSL reconstructions and modeled RSL trends. We identified three latitudinally-organized groups of sites that share coherent regional non-linear trends and indicate that dynamic redistribution of ocean mass by currents and/or winds was likely an important driver of sea-level change in the North Atlantic Ocean during the past ∼3000 years.