Sedimentary Records of the Evolution of the Melville Bugt Ice Stream

梅尔维尔巴格特冰流演化的沉积记录

• 批准号: 2280702
• 金额: --
• 依托单位: Queen's University Belfast
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2280702
• 关键词: Sedimentary; Records; Evolution; Melville; Bugt

In response to ongoing climate forcing the Greenland Ice Sheet (GrIS) has experienced changes in extent and mass balance, with implications for sea level and oceanography of the North Atlantic. Given that the GrIS has the potential to add up to ~7 m to global sea-level, and that over ~150 million people live within just 1 m of current sea-level, understanding the long-term history of the ice sheet is of global societal significance. A full understanding of past GrIS dynamics in response to climate change is key to modelling and projecting future scenarios. There is an increasing volume of data from studies of the Last Glacial Maximum (LGM) and Younger Dryas GrIS extent and retreat dynamics, but these data are heavily skewed towards Jakobshavn Isbræ in Disko Bugt, West Greenland. Outside this region there is a less well developed understanding of the timing and dynamics of deglaciation. For example, the seafloor of the Melville Bugt Trough (MBT) to the northwest of Disko Bugt has only recently been mapped and shows that ice reached the shelf edge at the LGM, making it ~80 km more advanced than previously thought (Newton et al., 2017). If the MBT was fully-occupied by an ice stream at the LGM, as suggested by seafloor landforms, it would have drained an area of the GrIS at least three times larger than Jakobshavn Isbræ (which currently drains ~7% of the GrIS), highlighting the need for a better understanding of its post-LGM evolution. This project aims to unravel the mechanisms and processes that drove ice sheet retreat in the past, and whether these processes were linear and steady or non-linear and catastrophic, through the analysis of sediments in MBT. The proximity of the study area to the recently identified meteor impact site in northwest Greenland means that complimentary evidence may also be preserved in the offshore sedimentary record (e.g. shocked quartz) and may help unravel the causes of the Younger Dryas. Analysis of lithological changes and the evolution of foraminifera assemblages will provide insights into the evolution of the West Greenland Current and its relationship with ice sheet dynamics in the region. To address these ideas six shallow sediment cores, retrieved from the study area in Melville Bugt, will be analysed using a range of sedimentological, palaeontological, geochemical, and statistical techniques. The results of these analyses will offer the opportunity to reconstruct palaeoceanography and environmental changes in this area of Greenland to develop a more complete picture of ice sheet evolution in the past and the potential implications this has for future scenarios under a warming climate.

对格陵兰冰盖（Gris）的回应，北大西洋上的质量平衡范围是质量的变化过去的GRIS动态响应气候变化的关键，从最后的冰川最大值（LGM）YAS GRIS范围和撤退动力学的研究中，数据越来越多。在外面的西部格陵兰岛的Disko Bugt中，与Disko Bugt西北的GT Truth（MBT）有关的时机和动态发展。 80公里（Newton等人，2017年）。在此过程中，这使冰盖撤退是线性的，稳定的或非线性的，并且该研究与西北格陵兰岛最近确定的流星撞击部位的灾难性E接近，这意味着在海上记录中也可以保留免费证据（例如，震惊的Quartz）并可能有助于揭开年轻的逻辑变化的原因，并且有孔虫组合的演变将提供给西格陵兰岛的演变，其Itshi P动态在一系列冰盖中。统计技术。在格陵兰岛的剧情中重建古生物学和环境变化的统计技术，以在TES T中形成更完整的图像，并且潜在的含义是在温暖的气候下对未来的情景。