Postglacial relative sea level change in Norway
Postglacial relative sea level change in Norway
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DOI：
10.1016/j.quascirev.2022.107422
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发表时间：
2022-03-15
影响因子：
4
通讯作者：
Menke, William
中科院分区：
文献类型：
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作者：
Creel, Roger C.;Austermann, Jacqueline;Menke, William
我们提出了挪威海岸从奥斯陆到科拉半岛的第一个综合冰川后相对海平面（RSL）数据库。该数据库跨越过去20年，由413个索引点和610个限制数据点组成，这些数据点来自凸起的海滩、考古数据、冰川海洋阶地和隔离盆地、盐沼和泥炭沼泽的沉积指标。数据经过质量控制，指定了标准化的指示意义，并根据当前标准重新校准。我们使用贝叶斯统计模型集合，对海平面指数点进行训练，并对其与指数和海平面限制点的拟合进行加权，以评估挪威RSL变化的时空格局。欧亚冰盖崩塌引起的均衡回弹驱动的连续RSL下降主导了挪威内陆各位置的RSL信号。在新仙女木期（14-11.7 ka）挪威西南部发生的第一次海侵（RSL上升事件）使某些地区的RSL升高了15米。第二次海侵发生在全新世早中期（10 ~ 5.5 ka）。时空模式集合约束了新仙女木和新带海侵的时间、幅度和空间分布。根据模拟结果，我们推测，带状海侵是全球平均海平面上升暂时超过均衡线驱动的RSL下降的结果，而新仙女木海侵可能是局部冰盖推进结合该地区低粘度软流圈和弱岩石圈的结果。此外，外周隆起对挪威RSL的影响导致了全新世早期RSL的增加和磁带海侵的延迟。研究表明，挪威冰期后的RSL数据包含了近场RSL变化的复杂时空格局，通过稳健的统计模型将高质量的数据汇编与冰川均衡调整模型相结合，可以最好地估计RSL变化。(c) 2022 Elsevier Ltd.版权所有。
We present the first comprehensive postglacial relative sea-level (RSL) database for the Norwegian coast from Oslo to the Kola Peninsula. The database spans the last 20 kyrs and is composed of 413 index points and 610 limiting data points derived from raised beaches, archeological data, glaciomarine terraces, and sedimentary indicators from isolation basins, salt marshes, and peat bogs. The data are quality controlled, assigned standardized indicative meanings, and recalibrated to current standards. We use an ensemble of Bayesian statistical models, trained on sea-level index points and weighted by their fit to both index and sea-level limiting points, to assess the spatiotemporal patterns of Norwegian RSL change. Continuous RSL fall driven by isostatic rebound in response to Eurasian ice sheet collapse dominates the RSL signal at every inland location in Norway. A first transgression (episode of RSL rise), which occurred in southwest Norway during the Younger Dryas (14-11.7 ka), increased RSL by as much as 15 m in some locations. A second transgression, named the Tapes transgression, occurred during the early-mid Holocene between 10 and 5.5 ka. The spatiotemporal model ensemble constrains the timing, amplitude, and spatial distribution of the Younger Dryas and Tapes transgressions. Based on our modeling results, we speculate that the Tapes Transgression was the result of global mean sea level rise temporarily outpacing isostasydriven RSL fall, while the Younger Dryas Transgression was likely the result of local ice sheet readvance combined with low viscosity asthenosphere and weak lithosphere in the region. We also describe the effects of peripheral bulge migration on Norwegian RSL, which caused increased RSL in the early Holocene and a delayed Tapes transgression. We show that postglacial RSL data in Norway contain complex spatiotemporal patterns of nearfield RSL change that can best be estimated by combining a high-quality data compilation with glacial isostatic adjustment modeling via a robust statistical model. (c) 2022 Elsevier Ltd. All rights reserved.