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Reconstructing paleoclimate and ice-sheet dynamics from continental slope deposits

从大陆坡沉积物重建古气候和冰盖动力学

基本信息

批准号：
NE/R018189/1
负责人：
Jenny Gales
金额：
$ 4.7万
依托单位：
Plymouth University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2018
资助国家：
英国
起止时间：
2018 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FR018189%2F1
关键词：
Reconstructing paleoclimate ice sheet dynamics

项目摘要

The aim of the project is to determine the different sediment types on the eastern Ross Sea continental slope, Antarctica. This will help to understand how the Ross Sea shelf and slope developed over time, and the different processes that operated there. This will allow us to reconstruct how the West Antarctic Ice Sheet and climate changed in the past, for example, how far ice extended from the Antarctic continent, how the ice fluctuated, and when these changes occurred. This is important in order for us to understand how ice may change around Antarctica in the future, and the effects this will have on global sea level. Understanding these changes is of significant global importance because Antarctica is experiencing rapid ice loss. This ice loss has doubled in recent years in places. This is due to changes in ocean and atmospheric circulation, with increased observations of warm water masses on the Antarctic shelf. Ocean warming is understood to be one of the main factors causing rapid ice-sheet retreat and instability, leading to potentially irreversible effects. There have also been changes in deep ocean currents in recent years. These currents have global importance as they transfer cold, salty waters to the deep ocean which eventually feed into global ocean currents. This ultimately affects global climate. Oceanographic measurements over the last three decades show significant changes in temperature, salinity, density and depth of the currents, impacting the supply of dense water to the deep ocean. To understand the record of past processes over millions of years, we will collect sediment samples by drilling up to 1 km beneath the seafloor using the drill ship JOIDES Resolution during the International Ocean Discovery Program (IODP) Expedition 374. The expedition is scheduled for January 2018. The main scientific objective is to identify what processes were operating on the continental slope over millions of years and how these processes were influenced by glacial / climate cycles. We will use a range of sampling techniques including obtaining sediment samples and downhole logging data, collected by lowering specialised logging equipment down the drilled holes in the seafloor. We will identify the different slope processes by analysing the sediment core material. This will help us to understand the occurrence, characteristics, frequency and timing of the different sediment deposits which will shed light on what processes were operating in the region. We will look at how the sediment deposits relate to glacial / climate cycles, based on analysis carried out during IODP Expedition 374. We will combine this with regional geophysical data, including information on the seafloor bathymetry and structure beneath the seafloor, to provide information about the shape of the seafloor surface and sub-surface. This will allow recent processes to be identified from seafloor morphology.

该项目的目的是确定南极洲罗斯海东部大陆坡的不同沉积物类型。这将有助于了解罗斯海陆架和斜坡如何随着时间的推移而发展，以及那里发生的不同过程。这将使我们能够重建西南极冰盖和气候过去如何变化，例如，冰从南极大陆延伸多远，冰如何波动，以及这些变化何时发生。这对于我们了解未来南极洲周围的冰层可能如何变化以及这将对全球海平面产生的影响非常重要。了解这些变化对于全球具有重要意义，因为南极洲正在经历快速的冰层流失。近年来，一些地方的冰损失增加了一倍。这是由于海洋和大气环流的变化，以及对南极大陆架暖水团的观测增加所致。海洋变暖被认为是导致冰盖快速消退和不稳定的主要因素之一，从而导致潜在的不可逆转的影响。近年来，深海洋流也发生了变化。这些洋流具有全球重要性，因为它们将寒冷的咸水转移到深海，最终注入全球洋流。这最终会影响全球气候。过去三十年的海洋学测量显示，洋流的温度、盐度、密度和深度发生了显着变化，影响了深海浓水的供应。为了了解过去数百万年来的过程记录，我们将在国际海洋发现计划 (IODP) 第 374 次探险期间，使用 JOIDES Resolution 号钻探船在海底钻探至 1 公里处，收集沉积物样本。此次探险计划于 2018 年 1 月进行。主要科学目标是确定数百万年来大陆坡上发生了哪些过程，以及这些过程如何受到冰川/气候循环的影响。我们将使用一系列采样技术，包括获取沉积物样本和井下测井数据，这些数据是通过将专门的测井设备放入海底钻孔来收集的。我们将通过分析沉积物芯材来识别不同的斜坡过程。这将帮助我们了解不同沉积物的发生、特征、频率和时间，从而揭示该地区正在发生的过程。我们将根据 IODP 第 374 次远征期间进行的分析，研究沉积物沉积与冰川/气候循环的关系。我们将其与区域地球物理数据（包括海底测深和海底下方结构的信息）相结合，以提供有关海底表面和地下形状的信息。这将使我们能够从海底形态中识别出最近的过程。