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

这项研究是一个跨学科项目的一部分，旨在确定阿拉斯加东南部北部（纬度57至62）正在进行的地壳变形的时空特征。本次调查的目标是目前世界上隆升率最高的地区（25至40毫米/年），相对板块运动为50毫米/年。初步结果显示了阿拉斯加东南部隆起和构造应变积累的有趣和非常令人兴奋的模式。在先前的研究中建立的80多个运动GPS站点网络正在被重新利用，以填补当前隆起和水平地壳变形的时空特征描述的空白，并提高大多数站点的精度。正在对两个地点进行检查，以从树木年代学和地貌学确定小冰河期和后小冰河期的隆起历史。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，在十年和百年时间尺度上提供更好的时空控制。这些野外调查的结果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部冰川和构造之间的关系。

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.