Proglacial landscape evolution across the Antarctic Peninsula with Holocene climate change

全新世气候变化影响整个南极半岛的前冰川景观演化

• 批准号: 2444876
• 金额: --
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2444876
• 关键词: Proglacial; landscape; evolution; across; Antarctic

The ice sheet margin around the Antarctic Peninsula receded rapidly from its Last Glacial Maximum (LGM) position on the continental shelf edge ~ 18 ka (Davies et al., 2012) to a position towards the head of fjords, and in some cases onto land. These former outlet glacier margins are marked by prominent (tens of km long) lateral moraine ridges along the major fjords. Coincidentally, sea level changes and isostasy created raised beaches, multiple shorelines and perched deltas (e.g. Fretwell et al., 2010). However, the rates and primary drivers of landscape evolution in NE Antarctic Peninsula in response to natural climate change are otherwise little known and are contentious, at least partly due to a lack of in situ observations, the variety of glaciation styles and complex paraglacial adjustments during and after the deglaciation. The Pleistocene-Holocene transition along the northern tip of Antarctic Peninsula is connected with a significant and rapid climate warming between 13 and 12 ka BP and predominant early Holocene hypsythermal conditions continuing until 9.5 ka BP (Mulvaney et al., 2012) resulting in consequent ice shelf collapse and glacier retreat (e.g. Bentley et al., 2005). A number of mid and late-Holocene advances have been proposed from a handful of sites (Hjort et al., 1997; Bentley et al., 2009; Carrivick et al., 2012), but there is an absence of widespread evidence for a Little Ice Age across the Antarctic Peninsula (Mulvaney et al., 2012).The opportunity to examine the composition, functioning and evolution of the ice-free proglacial parts of the Antarctic Peninsula is potentially extremely valuable, to yield new insights into the extent to which glaciers and their associated processes have shaped the landscape. These systems deliver vast volumes of meltwater and sediment to the bays and fjords of the Antarctic Peninsula (Griffith and Anderson, 1989; Kavan et al., 2017) and ultimately to the Southern Ocean. These water and sediment fluxes are controlled by glacier fluctuations (e.g. Diekmann et al., 2000; Evans et al., 2005) and in turn strongly influence mineral exports (e.g. Bown et al., 2018) and primary production and hence food webs in the Southern Ocean (e.g. Wefer and Fischer, 1991). This project aims to assess landscape evolution across the Antarctic Peninsula during the Holocene by using a novel combination of high-resolution 3D geospatial analysis; most likely including datasets such as the recently released REMA DEM and Planet imagery, and field surveys of geomorphology, sedimentology and with geochronological ambitions. It will develop the methods and analysis of Carrivick et al. (2018) as applied to the proglacial areas of the central European Alps. Field surveys will be based on the Ulu Peninsula of James Ross Island, the second largest ice free area in the whole of Antarctica Peninsula, with the support and logistics of the Czech J.G.Mendel Station. Combining these skills and approaches will permit local process-based interpretations and a regional picture to be assembled of Holocene landscape development across the Antarctica Peninsula. Questions concerning sediment fluxes from glaciated versus deglaciated catchments, geomorphological structure-composition (landforms), geomorphological functioning (e.g. connectivity) and terrestrial-fjord linkages will be addressed.

南极半岛周围的冰盖边缘从大陆架边缘上的最后一次冰川最大（LGM）位置迅速退出〜18 ka（Davies等，2012），到达峡湾头的位置，在某些情况下， 。这些以前的出口冰川边缘以沿主要峡湾的突出（长达数十km）的侧面山脊标记。巧合的是，海平面的变化和等值造成了高架海滩，多个海岸线和栖息的三角洲（例如Fretwell等，2010）。但是，响应自然气候变化的NE南极半岛景观演化的速率和主要驱动因素鲜为人知，并且是有争议的，至少部分是由于缺乏原位观察结果，冰川风格的种类，复杂的冰川冰期调整。并在退化之后。沿着南极半岛北端的更新世 - 三明过渡与13至12 ka bp之间的显着且快速的气候变暖有关，并且主要全新世催眠状态持续到9.5 ka bp（Mulvaney等人，2012年），从而导致ICE导致冰。搁板塌陷和冰川静修（例如Bentley等，2005）。已经从少数几个地点提出了许多中新世和后期的进步（Hjort等，1997； Bentley等，2009； Carrivick等，2012），但是没有广泛证据证明是整个南极半岛的冰河时代很少（Mulvaney等，2012）。检查南极半岛的无冰冰期部分的组成，功能和进化的机会可能非常有价值，可以产生新的洞察力，以使新的见解能够在范围内产生范围哪些冰川及其相关的过程塑造了景观。这些系统为南极半岛的海湾和峡湾提供了大量的融水和沉积物（Griffith and Anderson，1989; Kavan等，2017），并最终到达南海。这些水和沉积物通量受到冰川波动的控制（例如Diekmann等，2000； Evans等，2005），进而强烈影响矿物出口（例如Bown等，2018）和初级生产，并在食物网中，因此食物网。南大洋（例如Wefer and Fischer，1991）。该项目旨在通过使用高分辨率3D地理空间分析的新型组合来评估全新世期间整个南极半岛的景观演变；最有可能包括诸如最近发布的Rema Dem和Planet Imagery之类的数据集，以及对地貌学，沉积学和地球体学野心的现场调查。它将开发Carivick等人的方法和分析。 （2018年）适用于中欧阿尔卑斯山的前冰地区。现场调查将基于詹姆斯·罗斯岛（James Ross Island）的乌鲁半岛，詹姆斯·罗斯岛（James Ross Island）是整个南极半岛的第二大冰区，并获得了捷克J.G.Mendel站的支持和后勤工作。结合这些技能和方法将允许基于当地的解释，以及整个南极半岛全新世景观发展的区域图片。有关冰川和退化流域，地貌结构组合（地形），地貌功能（例如连通性）和地面 - 峡湾连接的问题。