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

智力价值：这笔小额探索性研究补助金的目标是利用1999年科学冰演习期间收集的声学数据制作阿拉斯加边缘的高分辨率水深图，以确定已知侵蚀北冰洋亚细亚盆地浅层地物的大冰盖是否源于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长笛证据支持这样一种假设，即厚厚的冰盖起源于加拿大北极群岛，在更新世期间将海底环境侵蚀到约700米深。为了明确地证明这些冰盖的起源，有必要将高分辨率的水深测量数据与SCICEX SideScan数据中已发现的线条进行比较，并记录发生的深度和地物的规模，作为与拟议的源区距离的函数。在SCICEX-99期间为阿拉斯加边缘收集的水深测量数据尚未得到处理，因为在获取这些数据时，潜艇在水柱中的垂直运动造成了不准确。这项工作将修改目前在声纳换能器上假定近乎恒定的水性质的现有软件，以生成平台在不断变化的水柱中移动的水深表。由此产生的水深数据集将可用于帮助研究阿拉斯加边缘SCICEX数据的海洋学家评估地形特征的长度尺度与观测到的水的物理和化学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詹妮弗·恩格斯的博士论文。她在法国尼斯的AGU/EGS会议和内华达州里诺的INQUA会议上介绍了她在SCICEX SideScan数据中发现的阿拉斯加边缘的冰川特征，并正在完成一份描述这一发现的手稿，将提交给《地质学》杂志。通过研究水深数据，恩格斯将从本质上将这一冰川故事延伸到第三个维度，从而记录下大片亚细亚冰盖的来源，并为该地区沉积物岩芯的年代测定奠定基础。这项研究对未来AUV在北冰洋的作业应该是有利的，在那里，飞行器在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.