Collaborative Research: Tree Ring Based Records of Temperature and Glacier Fluctuation Spanning the Past Two Millennia, Prince William Sound, Alaska

这项研究的主要目标是利用阿拉斯加南部威廉王子湾周围的活木材和亚化石木材，建立跨越过去2000年的连续树木年轮年表。这份年表将提供过去两千年来北太平洋气候的年度解析记录。此外，开发长年轮记录将涉及哥伦比亚和威廉王子湾周围其他冰川推进而死亡的树木的交叉年代测定；对这些冰川前场树木萌发和死亡日期的解释将使该地区的冰川波动能够以十年精度重建。亚化石日志将在威廉王子湾东部、北部和西部的五个地点进行采样。其中四个地点之前曾在早期的调查中进行过研究，并提供了跨越加州的树轮记录。公元100到700年和公元873年到1991年。进一步的采样将增加样本大小，从而提高这些现有采集中的年表信号质量，并缩小公元700年和873年之间的记录差距。关于冰山崩解冰川系统的动力学，人们对哥伦比亚冰川的第五个地点进行了深入的研究，但缺乏史前波动的详细记录。初步收集表明，哥伦比亚大学发现的树木年轮样本具有正确的年龄和长度，完全弥补了现有年轮记录中的差距，从而完成了跨越过去2000年的连续年轮系列。2000年的年轮宽度年表将是迄今为止北美从五大湖以北连续的最长的年轮系列。每年解析的气候记录将补充世界其他地方正在开发的其他此类数千年长的记录，并将用于对自然气候变异性的全球分析。追溯到公元1000年之前的历法冰川历史的发展将是第一次在任何地方实现这一点。这些陆地终止冰川波动的记录将提供过去温度和降水变化的综合替代记录，以补充树轮记录。哥伦比亚冰川波动的重建将包括推进的时间和速度，并允许评估这一潮水-裂解冰川系统的气候与非气候强迫。

The primary objective of this research is to develop a continuous tree-ring chronology spanning the past 2000-years from living and subfossil wood around Prince William Sound, southern Alaska. This chronology will provide an annually resolved record of North Pacific climate for the past two-millennia. In addition, development of the long tree-ring record will involve cross-dating of trees killed by advances of Columbia and other glaciers around Prince William Sound; interpretation of the dates of tree germination and death on these glacier forefields will enable glacier fluctuations in the region to be reconstructed with decadal precision.Subfossil logs will be sampled at five localities in eastern, northern and western Prince William Sound. Four of these sites have previously been studied during earlier investigations and provide tree-ring records spanning cal. AD 100 to 700 and AD 873 to 1991. Further sampling will increase sample size and hence chronology signals quality in these existing collections, and also reduce the gap in record between AD 700 and 873. The fifth site at Columbia Glacier has been intensively studied in regard to dynamics of the iceberg-calving glacier system, but lacks a detailed record of prehistoric fluctuations. Preliminary collections suggest the tree-ring samples to be found at Columbia are of the correct age and length to completely bridge the gap in the existing tree-ring records and so allow completion of a continuous tree-ring-series spanning the past two millennia.The 2000-year ring-width chronology will be the longest continuous tree-ring-series in North America from north of the Great Lakes to date. The annually resolved climate record will compliment other such multi-millennia length records being developed elsewhere in the world and be of use in global analyses of natural climate variability. The development of calendar-dated glacial histories extending back before AD 1000 will be the first time this has been achieved anywhere. These records of land-terminating glacial fluctuations will provide an integrated proxy record of past temperature and precipitation changes to compliment the tree-ring record. The reconstruction of fluctuations of Columbia Glacier will include timing and rates of advances, and allow evaluation of climatic versus non-climatic forcing of this tidewater-calving glacier system.