Glacier Changes in Western North America: Effects on Sea Level and Climatic Implications

在过去的十年里，人们测量了北美西北部大约100个冰川的海拔分布，其中许多冰川不止一次。与旧地图一起使用，这些地图允许计算不同时间间隔的表面高程和体积的变化。这是一项为期两年的后续研究，目的是完成数据处理和归档，并执行几项解释任务。这些任务中的第一项将是改进外推已测量冰川变化的技术，以获得未测量冰川的体积变化。这将需要编制一份夏末雪线区域地图，以帮助确定气候区域。第二项解释任务涉及从数据中去除冰川流动的影响，以便这些变化可以仅与气候有关。最后的任务是解释这些修正后的当地和区域气候变化，并预测在特定气候情景下未来冰川将发生什么。广泛影响：这项研究将从科学的角度进行，但也有几个应用。最明显的是精确地确定阿拉斯加的冰川对海平面上升有多大贡献，以及在各种气候情景下未来可能做出什么贡献。最近的贡献比最初预测的要大得多，可能会超过主要冰盖的贡献。最近一篇描述这些结果的论文引起了全世界媒体的关注。另一个应用与工程有关：冰川和冰川变薄对供水的影响。最近，阿拉斯加的一个例子再次浮出水面，当时一名国会议员敦促重新提出在阿拉斯加山脉的苏西特纳盆地进行大规模水电开发项目的提案。

ABSTRACTEchelemeyerOPP-0327067Over the past decade the elevation profiles of about 100 glaciers in northwestern North America have been measured, many of them more than once. Used along with old maps, these permit changes in surface elevation and volume to be calculated for different time intervals. This is a twoyear follow-up study to complete data processing and archiving, and to perform several interpretative tasks. The first of these tasks will be to improve techniques for extrapolating the changes on measured glaciers to obtain the volume changes of unmeasured ones. This will require the compilation of a regional map of late summer snowlines to help define climate regions. The second interpretative task involves removing the effects of glacier flow from the data, so that the changes can be related to climate alone. The final task is to interpret these corrected changes interms of local and regional climate, and to predict what will happen to the glaciers in the future under specified climate scenarios.Broader Impacts: The research will be carried out from a scientific perspective, but there are several applications. The most obvious is the refined determination of how much the glaciers of Alaska have contributed to the rise in sea level, and what future contributions are likely to be under various climate scenarios. The recent contribution has been much larger than originally predicted, and may exceed that from the major ice sheets. A recent paper describing these results attracted worldwide press attention. The other application relates to engineering: the effect of glaciers and glacier thinning on water supply. One example in Alaska recently re-surfaced when a congressmanurged the revival of a proposal for a huge hydro-power development project in the Susitna basin of the Alaska Range.