High-resolution Bathymetry of the Alaska Margin Derived from SCICEX/SCAMP Data

知识价值：这项探索性研究小额赠款（SGER）的目标是利用1999年科学冰演习（SCICEX）期间收集的声学数据绘制阿拉斯加边缘的高分辨率水深图，以确定是否有大型冰盖侵蚀了北冰洋美亚混血人盆地的浅层特征，这些冰盖来自加拿大北极群岛附近的冰川。最近在阿拉斯加边缘发现的冰川期凹槽的证据支持了厚冰盖起源于加拿大北极群岛的假设，在更新世期间侵蚀了海底周围约700米的深度。为了明确地证明这些冰盖的起源，有必要将高分辨率测深数据与sciex侧扫描数据中已经发现的线条进行比较，并记录发生深度和特征规模作为与拟议源区域距离的函数。在sciex -99期间收集的阿拉斯加边缘测深数据没有进行处理，因为这些数据在获取时潜艇在水柱中的垂直运动造成了不准确性。这项工作将修改现有的软件，该软件目前假设声纳换能器的水属性接近恒定，从而为通过变化的水柱移动的平台生成水深表。由此产生的水深数据集将用于帮助海洋学家研究阿拉斯加边缘的SCICEX数据，评估地形特征的长度尺度与观测到的物理和化学水性质变化之间的关系。更广泛的影响：这个项目将作为夏威夷大学研究生Jennifer Engels的博士论文。她在法国尼斯举行的AGU/EGS会议和内华达州里诺举行的INQUA会议上展示了她在阿拉斯加边缘的SCICEX侧扫描数据中发现的冰川特征，并正在完成一份描述这一发现的手稿，准备提交给《地质学杂志》。通过检查水深数据，恩格斯将从本质上把这个冰川形成的故事扩展到第三个维度，恩格斯将记录大型美亚冰盖的来源，并为该地区沉积物岩心的定年奠定基础。这项研究将有利于未来在北冰洋的AUV作业，在那里，当车辆收集声学数据时，可能会在水柱的垂直和水平变化中移动。

Intellectual Merit: The goal of this Small Grant for Exploratory Research (SGER) is to prouce high-resolution bathymetric maps of the Alaska margin using acoustic data collected during the 1999 SCience ICe EXercise (SCICEX) to determine whether large ice sheets known to have eroded shallow features in the Amerasian Basin of the Arctic Ocean derived from glaciers adjacent to the Canadian Arctic Archipelago. Recently discovered evidence of glacigenic flutes on the Alaska margin supports the hypothesis that thick ice sheets originated in the Canadian Arctic Archipelago, eroding submarine environs to depths of ~700 m during the Pleistocene. To demonstrate unequivocally where these ice sheets originated, it is necessary to compare high-resolution bathymetry data with the lineations already discovered in SCICEX sidescan data and document the depth of occurrence and scale of features as a function of distance from the proposed source region. The bathymetry data collected for the Alaska margin during SCICEX-99 have not been processed due to inaccuracies caused by the vertical motion of the submarine through the water column as these data were acquired. This effort will modify existing software that presently assumes near-constant water properties at the sonar transducers to generate bathymetric tables for a platform that is moving through a changing water column. The resultant bathymetric dataset will be available to help oceanographers studying SCICEX data along the Alaska margin evaluate how the length scales of topographic features relate to the observed changes in physical and chemical water properties. Broader Impacts: This project will serve as a doctoral thesis for Jennifer Engels, a graduate student at the University of Hawaii. She has presented her discovery of the glacigenic features in SCICEX sidescan data for the Alaska margin at both the AGU/EGS meeting in Nice, France and the INQUA meeting in Reno, Nevada, and is completing a manuscript describing this discovery for submission to the Journal of Geology. By examining the bathymetric data, which will essentially extend this glacigenic story into the third dimension, Engels will document the source of the large Amerasian ice sheets and lay the foundation for dating sediment cores in the region. This study should be advantageous for future AUV operations in the Arctic Ocean, where vehicles will likely move through both vertical and horizontal changes in the water column as they collect acoustic data.