"Warm Times, Cold Times:-Quantitative Reconstructions of Near-Shore Environments Over the Last 2000 Years in Vestfirdir, NW Iceland: Natural Changes and Human Responses

更好地了解未来的环境变化是当今人类社会的迫切需要，可以通过重建过去变化的范围和速率来测试和评估预测。 该项目的目标是在过去的2000年里，冰岛北部的海洋气候的定量重建。 选择冰岛北方是因为它的敏感位置。 这个小区域包含了整个北大西洋大部分地区的气候变化，因为它位于大西洋和极地/北极地区之间的边界，这推动了大部分变化。此外，这是气候重建的理想区域，因为它拥有1）现代仪器气候数据的广泛数据库，2）1，200年的历史文献气候记录，以及3）日期明确的高分辨率沉积物岩心，其中包含自然气候变化的档案。这项研究将根据西菲尔迪尔三个海洋岩心中海洋软体动物的稳定同位素组成，重建季节和年度温度变化。 同位素数据将根据现代仪器记录进行校准，并应用于岩心中的软体动物。 通过分析60个人的寿命为2到10年，他们生活在现代，通过冰岛的定居（公元871年）和人类影响的间隔到c。两千年前。 在海洋岩心中使用微磨软体动物是目前从冰岛获得季节性至年度分辨率气候数据的唯一途径，而不是仪器记录和文件记录。 通过分析其他传统的代理记录，将简短但每年解决的记录置于环境框架内。根据对这些岩心的早期分析，确定了过去的主要环境变化。其中包括70年至400年B. P.之间的长期“冷”间隔。公元1930年回到1600年），一个较低的区间？18 O（CaCO 3）（较暖）值大约在公元1000年，而一个冷的间隔集中在公元670年。 该项目将在这些. warm中选择软体动物进行分析。冷。的间隔 为了研究这些变化的人类层面，重点将放在冰岛的解决（c。871.第871章到现在基于同位素的温度重建将用于评估冰岛海冰发生率和渔业渔获量的历史记录，主要目标是：1）确定海洋变化在冰岛渔业生产力中的作用; 2）隔离非气候因素可能在渔业变化中发挥作用的时期。将通过底栖有孔虫组合的变化来衡量重建后的海洋气候对生物多样性的影响。更广泛的影响 该项目是对气候变化对近岸海洋气候的作用及其与历史渔业做法和渔获量变化的关系的多学科评价和分析。 这是一项国际努力，来自美国和加拿大的研究人员以及冰岛的几位同事合作。 它还促进了NSF和Rannis（冰岛科学基金会）之间的合作。将加强与目前在冰岛北方从事动物考古工作的考古界的联系。 这项合作将有助于分析在海洋中发现的鱼类耳石上的稳定同位素。 这些地点的垃圾和比较这些变化与稳定同位素数据从海洋核心。 该项目将对研究生和本科生进行教育，并将有助于培训地球化学方法和微观及宏观古生物学方面的年轻科学家。

ABSTRACTAndrewsOPP-0327187A better understanding of future environmental change is a pressing need of human society today and projections can be tested and evaluated by reconstructing the ranges and rates of past changes. The goal of this project is to develop a quantitative reconstruction of the marine climate Vestfirdir, north Iceland over the last 2000 years. Northern Iceland was chosen because of its sensitive location. This small area encapsulates climatic changes throughout much of the North Atlantic because it lies at the boundary between the Atlantic and Polar/Arctic realms, which drive much of the change. In addition, this is ideal area for climate reconstruction because it has 1) an extensive database of modern instrumental climate data, 2) a 1,200 year historical documentary climate record, and 3) well dated, high-resolution sediment cores containing an archive of natural climate variability. The research will reconstruct seasonal and annual temperature variations based on the stable isotopic composition of marine molluscs from three marine cores in Vestfirdir. The isotope data will be calibrated against the modern instrumental record and applied to molluscs in the cores. Seasonal to annual temperature estimates will be achieved through analysis of 60 individuals, with life spans of two to ten years, that lived during modern times, through the Settlement of Iceland (AD 871) and beyond the interval of human impact to c. 2000 years ago. The use of the micromilled molluscs in marine cores is the only way, at present to obtain seasonally- to-annually resolved climate data from Iceland, beyond the instrumental and documentary record. The short, but annually resolved records are placed within an environmental framework through analysis of other traditional proxy records. Drawing on earlier analyses of these cores, major environmental changes of the past are identified. These include a prolonged "cold" interval between 70 and 400 yr B.P. (ca. AD 1930 back to 1600), an interval with lower ?18O (CaCO3) (warmer) values around AD 1000, and a cool interval centered at AD 670. The project will select molluscs for analysis within these .warm. and .cold. intervals. In order to study the human dimensions of these changes, emphasis will be placed on the period from the Settlement of Iceland (c. AD 871) to the present. Isotope-based temperature reconstructions will be used to evaluate historical records of Icelandic sea-ice incidence and fisheries catches, with the main goals of: 1) determining the role of oceanic variability in the productivity of Icelandic fisheries; and 2) isolating periods when non-climatic factors might have played a role in fisheries variations. The impact of the reconstructed marine climates on biodiversity will be measured by changes in benthic foraminiferal assemblages. Broader Impacts This project represents a multidisciplinary evaluation and analysis of the role of climate change on the nearshore marine climate and its association with changes in historical fisheries practices and catches. It represents an international effort, with researchers from the USA and Canada and with co-operation from several colleagues in Iceland. It also fosters collaboration between NSF and Rannis (the Icelandic Science Foundation). Links with the archeological community currently working on the zooarcheology of sites in northern Iceland will be strengthened. This collaboration will enable analysis of stable isotopes on fish otoliths found in the refuse from these sites and comparison of these variations with the stable isotope data from the marine cores. The project will educate both graduate and undergraduate students, and will be beneficial in the training of young scientists in geochemical methods and micro- and macro -paleontology.