A Towed Electromagnetic Survey System for Mapping Shallow Sedimentation Porosity

已提供资金购买和开发拖曳式电磁测量系统，以确定大陆架和陆坡上部沉积柱（海底以下1至20米）的孔隙结构。这种装置建立在加拿大开发的一种类似但独特的系统基础上，该系统已成功用于识别浅层天然气和/或淡水渗漏区域。该方法能够提供比目前存在的任何其他技术更大面积的沉积孔隙度的定量估计。拖曳EM仪器是唯一能够提供非粘性沉积物孔隙度定量估计的工具。将电磁数据与更传统的地球物理测量相结合，使研究人员能够了解沉积物的孔隙度和渗透率如何随时间而演变。电磁测量系统将以多学科的方式用于确定大陆架形成和演变的过程，大陆架是大陆和深海之间的关键边界。特别是，它们直接涉及理解浅水沃茨的过程和产品的问题，这是MARGINS倡议确定的一个关键研究领域。

Funds are provided to purchase and develop a towed electromagnetic (EM) survey system which determines the porosity structure of the upper sediment column (1-20m below seafloor) across the continental shelf and slope. Such a device builds upon a similar, but unique system developed in Canada that was successfully used to identify regions of shallow gas and/or fresh water seeps. The method is able to provide quantitative estimates of sedimentary porosities over much larger areas than any other technique that currently exists. Towed EM instruments are the only tools able to provide quantitative estimates of porosity in noncohesive sediments. Combining EM data with more conventional geophysical measurements allows investigators to understand how porosity and permeability of sediments evolve through time.The EM survey system will be used in a multi-disciplinary manner to determine processes which shape the formation and evolution of the continental shelf, the critical boundary between continent and deep ocean. In particular they directly address issues of understanding process and product in shallow waters, identified as a key research area by the MARGINS initiative.