Holocene relative sea‐level changes in Harris, Outer Hebrides, Scotland, UK
Holocene relative sea‐level changes in Harris, Outer Hebrides, Scotland, UK
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英国苏格兰外赫布里底群岛哈里斯全新世相对海平面变化
DOI：
10.1002/jqs.1281
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发表时间：
2010
影响因子：
2.3
通讯作者：
A. Dawson
中科院分区：
文献类型：
--
作者：
J. Jordan;David E. Smith;S. Dawson;A. Dawson
在苏格兰外赫布里底斯的哈里斯大西洋海岸的两个地点，利用地层学、粒度和硅藻分析以及放射性碳测年，研究了全新世中期和晚期相对海平面变化的证据。发现的最早的事件是发生在7982-8348年之后的一次海洋洪水。A(7370 ± 80 14C a)BP，当海水在撤离前越过位于−0.08 m兵器基准面(−2.17 m平均高水位泉)的门槛时。这可能是由于一场风暴或全新世的斯托雷加滑坡海啸造成的。由6407-6122拨打。(5 5 0 0 ± 6 0 14C a)BP，相对海平面已经开始下降，指示的最高水平面在0.0 8至−1.96 m(−2.0 1至−4.0 5 m)之间。在5841-5050卡之后，这一下降达到了−0.30到−2.35 m(−2.39到−4.44 m)之间。A(4760 ± 13014Ca)BP，但随后相对海平面上升5450-4861卡，达到0.54-−1.57 m(−1.55-−3.66 m)。A(45 0 0 ± 10 0 14C a)BP。这种上升持续下去，可能有一个中断，直到在2952年至3375卡之间达到第二个沙坪表面，介于2.34至−0.26 m(0.25%至−2.35 m)之间。A(3000 ± 80 14C a)和1948-2325年卡。A(2 130 ± 70 14C a)BP，未达到目前水平。从最早的砂坪开始的退缩事件与冰后主要海岸线的放弃有关。人们认为，记录的相对海平面波动可以与冰川均衡中心外围其他类似事件相关联，因此可能反映了近岸海平面的长期变化。尽管已公布的证据来自该地区不同冰盖负荷的剪切线，但没有证据表明相关地点之间的隆升存在差异。版权所有©2009 John Wiley&Sons，Ltd.
Evidence for relative sea‐level changes during the middle and late Holocene is examined from two locations on the Atlantic coast of Harris, Outer Hebrides, Scotland, using morphological mapping and survey, stratigraphical, grain size and diatom analysis, and radiocarbon dating. The earliest event identified is a marine flood, which occurred after 7982–8348 cal. a (7370 ± 80 14C a) BP, when the sea crossed a threshold lying at −0.08 m Ordnance Datum Newlyn (OD) (−2.17 m mean high water springs (MHWS)) before withdrawing. This could have been due to a storm or to the Holocene Storegga Slide tsunami. By 6407–6122 cal. a (5500 ± 60 14C a) BP, relative sea levels had begun to fall from a sandflat surface with an indicated MHWS level of between 0.08 and −1.96 m (−2.01 to −4.05 m). This fall reached between −0.30 and −2.35 m (−2.39 to −4.44 m) after 5841–5050 cal. a (4760 ± 130 14C a) BP, but was succeeded by a relative sea‐level rise which reached between 0.54 and −1.57 m (−1.55 to −3.66 m) by 5450–4861 cal. a (4500 ± 100 14C a) BP. This rise continued, possibly with an interruption, until a second sandflat surface was reached between 2.34 and −0.26 m (0.25 to −2.35 m) between 2952–3375 cal. a (3000 ± 80 14C a) and 1948–2325 cal. a (2130 ± 70 14C a) BP, before present levels were reached. The regressive episode from the earliest sandflat is correlated with the abandonment of the Main Postglacial Shoreline. It is maintained that the fluctuations in relative sea level recorded can be correlated with similar events elsewhere on the periphery of the glacio‐isostatic centre and may therefore reflect secular changes in nearshore sea surface levels. Despite published evidence from trim lines of differential ice sheet loading across the area, no evidence of variations in uplift between the locations concerned could be found. Copyright © 2009 John Wiley & Sons, Ltd.