Doctoral Dissertation Research: Human-Landscape Interactions and Response to Holocene Sea-Level Rise and Climate Change in Coastal New Hampshire, USA

Peter Leach将负责全新世中期到晚期人类、文化材料和景观对海平面上升、气候变化和生态系统变异的反应的调查。这将通过对美国缅因湾全新世中晚期潮间带考古遗址的地质考古评估来完成。这个接触前的多组分遗址被全新世晚期海平面上升淹没，现在被1.0-2.0米的盐沼泥炭所掩埋。由于该遗址被淹没，它展示了未燃烧的动物遗骸，多组分地层和有机物质的特殊保存。主要目标是了解遗址淹没的时间和自然，绘制文化材料和自然特征的空间分布，并继续对短期地貌过程进行高分辨率无人机（UAV）分析。了解保存潜力和当地地理/地质变量的影响将大大加强通过海平面上升遗址生存的建模。这将产生与埋在离岸较远的旧场址有关的信息。目前的项目和相关的未来研究将提供本科生和研究生培训，并将产生适合公众传播的科学数据。项目结果将提高人们对盐沼下潜在接触前场地的认识，这是一个在建筑和工程活动中经常被忽视的研究区域。项目数据阐明了潮间带和水下遗址需要付出的努力和研究潜力，将有利于历史保护官员。这反过来应导致在湿地修复或基础设施改善期间改善有关环境影响评估的规定。这些和其他数据将表明需要持续监测，并强调查明受海岸侵蚀威胁的考古遗址的紧迫性。在北美东北部和北半球的许多其他地区，全新世早期至中期的沿海遗址由于海平面的相对上升而被淹没，并可能由于当地的地貌因素而得到不同程度的保存。研究人员试图了解过去和正在进行的地貌过程，这些过程会影响人类对景观的利用，以及对淹没和潮间带遗址的长期保护潜力。研究人员将使用放射性碳定年法来限制遗址组成部分的年龄和海平面上升的时间。实验室技术将提取和稳定涝渍地区特有的有机物质。传统的考古现场方法将通过人工岩心提取、高分辨率无人机调查和密集的空间数据分析得到增强。现场水平的推断将增强海洋越界景观的地质模型，并证明需要在考古尺度上进行改进。无人机测绘优于激光雷达和粗尺度定性侵蚀评估，研究人员对该技术的创新使用将产生定量数据并改进短期（单风暴事件）侵蚀和沉积模型。虽然目前的项目侧重于接触前人类和生态系统对海平面上升和气候变化的反应，但所产生的数据将有助于模拟类似系统对未来环境变化的反应。

Peter Leach will undertake an investigation of the response of mid- to late-Holocene people, cultural materials and landscapes to sea-level rise, climate change and ecosystem variability. This will be accomplished through geoarchaeological evaluation of an intertidal mid-to-late Holocene archaeological site on the Gulf of Maine, USA. This precontact, multi-component site was drowned by late Holocene sea-level rise and it is now buried by 1.0-2.0 meters of salt marsh peat. Because the site was submerged, it exhibits exceptional preservation of unburned faunal remains, multi-component stratigraphy, and organic materials. The main goals are to understand the timing and nature site submergence, map the spatial distribution of cultural materials and natural features, and to continue high-resolution unmanned aerial vehicle [UAV] analyses of short-term geomorphic processes. An understanding of preservation potential and the influence of local geographic/geological variables will greatly enhance modeling of site survival through sea-level rise. This will generate information relevant to older sites buried farther offshore. The current project and related future research will provide undergraduate and graduate student training and will generate scientific data ideally suited for public dissemination. Project results will raise awareness of precontact site potential beneath salt marshes, a study area that is frequently overlooked during construction and engineering activities. Project data will benefit Historical Preservation Officers by elucidating the effort required and research potential of intertidal and submerged sites. This in turn should lead to improved regulations regarding environmental impact assessments during wetland remediation or infrastructure improvements. These and other data will demonstrate the need for continuous monitoring and underscore the urgency of identifying archaeological sites threatened by coastal erosion.In northeastern North America and many other northern hemisphere locations, early- to mid-Holocene coastal sites were submerged through relative sea-level rise and are likely variably preserved due to local geomorphic factors. The investigators seek an understanding of past and on-going geomorphic processes that influence human use of landscapes and long-term preservation potential of submerged and intertidal sites. The researchers will use radiocarbon dating to constrain the age of site components and the timing of sea-level rise. Laboratory techniques will extract and stabilize organic materials unique to waterlogged sites. Traditional archaeological field methods will be augmented by manual core extraction, high-resolution UAV surveys, and intensive spatial data analyses. Site-level inferences will augment geologic models of marine-transgressed landscapes and demonstrate the need for refinement at archaeological scales. UAV mapping is superior to LiDAR and coarse-scale qualitative erosion assessments, and the researchers' innovative use of this technology will generate quantitative data and improve models of short-term (single storm event) erosion and deposition. Though the current project focuses on precontact human and ecosystem responses to sea-level rise and climate change, data generated will help to model the responses of similar systems to future environmental variations.