Active Tectonics, Glacier Load History and Post-Little-Ice-Age Isostatic Rebound in Southeastern Alaska

阿拉斯加东南部的活动构造、冰川负荷历史和后小冰期均衡回弹

• 批准号: 0229934
• 负责人: Roman Motyka
• 金额: $ 10.49万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-02-01 至 2005-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0229934&HistoricalAwards=false
• 关键词: Active; Tectonics; Glacier; Load; History

This study is part is an interdisciplinary program to determine the spatial and temporal characteristics of ongoing crustal deformation in the northern part of southeastern Alaska (latitude 57 to 62). The target of this investigation is a region that is currently experiencing the highest rates of uplift in the world (25 to 40 mm/yr) and where relative plate motion is 50 mm/yr. Preliminary results show an interesting and very exciting pattern of uplift and tectonic strain accumulation in southeastern Alaska.A network of 80+ campaign GPS sites established during a prior study are being re-occupied to fill gaps in delineation of the spatial and temporal characteristics of current uplift and horizontal crustal deformation, and to improve the precision at most of the sites. Two sites are being examined to determine Little Ice Age and post-Little Ice Age uplift history from dendrochronology and geomorphology. This additional data will fill gaps in both far-field locations where uplift is lowest and in regions where uplift has been greatest, providing better temporal and spatial control on decadal and centennial time scales. The results of these field investigations are being used to develop two- and three-dimensional isostatic rebound models, to analyze plate tectonic deformation, and to evaluate the relationship between glaciations and tectonics in the northern part of southeast Alaska.

这项研究是一个跨学科的计划，以确定在阿拉斯加东南部（纬度57至62）的北方正在进行的地壳变形的空间和时间特征的一部分。 本次调查的目标是一个地区，目前正在经历最高的隆升率在世界上（25至40毫米/年），其中相对板块运动是50毫米/年。 初步结果显示，阿拉斯加东南部的隆升和构造应变积累模式非常有趣和令人兴奋。在先前的研究中建立的80多个活动GPS站点的网络正在被重新占用，以填补当前隆升和地壳水平形变时空特征描绘的空白，并提高大多数站点的精度。 目前正在对两个地点进行检查，以根据树木年代学和地貌学确定小冰期和小冰期后的隆升历史。这些额外的数据将填补隆起最低的远场位置和隆起最大的区域的空白，从而在十年和百年时间尺度上提供更好的时间和空间控制。这些实地调查的结果正被用于开发二维和三维均衡反弹模型，分析板块构造变形，并评估阿拉斯加东南部北方冰川作用与构造之间的关系。