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

来自 SCICEX/SCAMP 数据的阿拉斯加边缘高分辨率测深

• 批准号: 0401692
• 负责人: Margo Edwards
• 金额: $ 3.16万
• 依托单位: University of Hawaii
• 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: 2003-12-15 至 2004-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0401692&HistoricalAwards=false
• 关键词: resolution; Bathymetry; Alaska; Margin; Derived

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.

智力优势：这项探索性研究小额赠款的目的是利用1999年科学冰演习（SCICEX）期间收集的声学数据制作阿拉斯加边缘的高分辨率测深图，以确定已知已侵蚀北冰洋美亚海盆浅层特征的大冰盖是否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成冰槽的证据支持了这样一种假设，即厚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米的深度。为了明确地表明这些冰盖的起源地，有必要将高分辨率测深数据与SCICEX侧扫数据中已经发现的线理进行比较，并将出现的深度和特征的规模作为与拟议源区距离的函数记录下来。 SCICEX-99期间为阿拉斯加边缘收集的测深数据尚未处理，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。 这项工作将修改现有的软件，目前假设在声纳传感器接近恒定的水的属性，以产生水深表的平台，是通过不断变化的水柱移动。 由此产生的测深数据集将用于帮助海洋学家研究沿着阿拉斯加边缘的SCICEX数据，评估地形特征的长度尺度与观测到的水的物理和化学性质的变化之间的关系。更广泛的影响：该项目将作为夏威夷大学研究生詹妮弗·恩格斯的博士论文。她在法国尼斯举行的AGU/EGS会议和内华达州里诺举行的INQUA会议上介绍了她在阿拉斯加边缘的SCICEX侧扫数据中发现的成冰特征，并正在完成一份描述这一发现的手稿，以提交给《地质学杂志》。通过检查测深数据，这将基本上扩展到第三个维度的冰川形成的故事，恩格斯将记录大美亚冰盖的来源，并奠定了该地区的沉积物芯的年代基础。这项研究应有利于今后在北冰洋的自主式潜水器作业，在那里，潜水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。