An examination of spatial variability in the timing and magnitude of Holocene relative sea-level changes in the New Zealand archipelago
An examination of spatial variability in the timing and magnitude of Holocene relative sea-level changes in the New Zealand archipelago
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DOI：
10.1016/j.quascirev.2015.09.025
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发表时间：
2016-01-01
影响因子：
4
通讯作者：
Sloss, Craig R.
中科院分区：
文献类型：
--
作者：
Clement, Alastair J. H.;Whitehouse, Pippa L.;Sloss, Craig R.
全新世相对海平面（RSL）的变化已被重建的四个地区在新西兰群岛：北方北岛（包括北岛，奥克兰，和科罗曼德尔半岛）;北岛的西南海岸;坎特伯雷海岸（南岛）;和奥塔哥海岸（南岛）。在北岛，RSL高位开始。8100-7240 cal yr BP时，目前的平均海平面（PMSL）首次达到。这是C。600-1400年前，比以前已表明的新西兰地区作为一个整体，是一致的，最近全新世RSL重建从澳大利亚。在北岛的位置早全新世海平面高位是相当明显的，与RSL高达2.75米高于现在。在南岛，高水位条件的出现较晚，第一次达到PMSL是在7000-6400 cal/yr BP之间。中全新世北岛北方经历了最大的海平面上升，RSL比现在高3.00 m。这明显高于北岛西南部和奥塔哥地区记录的最高水位。一些不同的驱动程序在一系列的规模可能是负责的空间和时间变化的时间和幅度的RSL的变化在新西兰群岛。一个可能的机制是RSL的南北梯度，这将出现在南极洲周围的中间场，以响应南极冰盖（AIS）的重力吸引力减少，因为它在全新世期间失去了质量。这种梯度将被预测的变形的岩石圈在南极周围的南大洋的中间字段由于流体均衡负荷和AIS的质量损失。然而，在新西兰地区的冰川均衡调整（GIA）模型预测中，海面高度或固体地球变形中没有这种长波长信号，而澳大利亚的研究表明，由于水文均衡影响，全新世RSL变化的南北变化是有限的或不存在的。在区域到地方尺度上，冰后期融水加载在新西兰周围的大陆架上的GIA模型预测有显着的影响，通过大陆勒韦林的现象的RSL变化的时间和幅度。大陆勒韦林的空间变化是由海岸的配置和相邻大陆架的宽度，与大陆勒韦林提供了一个强大的解释所观察到的空间和时间变化RSL的变化。需要进一步的研究，以确定不同的构造制度，波浪气候和沉积物制度的区域和当地的影响。这些都是潜在的非常重要的驱动RSL的变化，在区域到本地规模。然而，其潜在影响的程度仍然不明确。(C)2015爱思唯尔有限公司版权所有。
Holocene relative sea-level (RSL) changes have been reconstructed for four regions within the New Zealand archipelago: the northern North Island (including Northland, Auckland, and the Coromandel Peninsula); the southwest coast of the North Island; the Canterbury coast (South Island); and the Otago coast (South Island). In the North Island the RSL highstand commenced c. 8100-7240 cal yr BP when present mean sea-level (PMSL) was first attained. This is c. 600-1400 years earlier than has been previously indicated for the New Zealand region as a whole, and is consistent with recent Holocene RSL reconstructions from Australia. In North Island locations the early-Holocene sea-level highstand was quite pronounced, with RSL up to 2.75 m higher than present. In the South Island the onset of highstand conditions was later, with the first attainment of PMSL being between 7000-6400 cal yr BP. In the mid-Holocene the northern North Island experienced the largest sea-level highstand, with RSL up to 3.00 m higher than present. This is demonstrably higher than the highstand recorded for the southwest North Island and Otago regions. A number of different drivers operating at a range of scales may be responsible for the spatial and temporal variation in the timing and magnitude of RSL changes within the New Zealand archipelago. One possible mechanism is the north-south gradient in RSL that would arise in the intermediate field around Antarctica in response to the reduced gravitational attraction of the Antarctic Ice Sheet (AIS) as it lost mass during the Holocene. This gradient would be enhanced by the predicted deformation of the lithosphere in the intermediate field of the Southern Ocean around Antarctica due to hydro-isostatic loading and mass loss of the AIS. However, no such long-wavelength signals in sea-surface height or solid Earth deformation are evident in glacial isostatic adjustment (GIA) model predictions for the New Zealand region, while research from Australia has suggested that north-south variations in Holocene RSL changes due to hydro-isostatic influences are limited or non-existent. At the regional-to local-scale, post-glacial meltwater loading on the continental shelf around New Zealand is predicted by GIA modelling to have a significant effect on the timing and magnitude of RSL changes through the phenomenon of continental levering. The spatial variation in continental levering is controlled by the configuration of the coast and the width of the adjacent continental shelf, with continental levering providing a robust explanation for the observed spatial and temporal variations in RSL changes. Further research is required to characterise the regional and local effects of different tectonic regimes, wave climates, and sediment regimes. These are potentially very significant drivers of RSL variability at the regional-to local-scale. However, the magnitude of their potential effects remains equivocal. (C) 2015 Elsevier Ltd. All rights reserved.