Doctoral Dissertation Research: Quantitative Hydraulic Models for Jokulhlaup-Type Outflow Channels on Mars: Application of Earth Analogues, Geomorphology, and Remote Sensing

博士论文研究：火星 Jokulhlaup 型流出通道的定量水力模型：地球模拟、地貌学和遥感的应用

• 批准号: 0825621
• 负责人: Sheryl Luzzadder-Beach
• 金额: $ 1.13万
• 依托单位: George Mason University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0825621&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Quantitative; Hydraulic

Studies of Earth analogues of planetary bodies are used primarily to test hypotheses about phenomena that may be similar to those on Earth. This doctoral dissertation research uses Earth analogues to test the hypothesis that the massive fluvial channels on Mars and their observed geomorphic features were formed by a combination of surface water flow and eruptions from ground water confined by a cryolithospheric layer. These types of eruptions are termed "Jökulhlaup", from an Icelandic term that describes an abrupt release of massive amounts of water from behind or beneath a glacier. There are also similar locations on the Earth's surface, including the Cheney-Palouse Scablands in eastern Washington (associated with Glacial Lake Missoula) and the Jökulsá á Fjöllum channel at Vatnajökull glacier in Iceland. These Earth analogues were formed by jökulhlaup-type outburst floods in the geologic past, and so should provide insights into processes on Mars, where the size of the source basins is not sufficient to create the fluvial and geomorphic features observed, especially given the lower planetary gravitational constant. This research encompasses the use of space-borne remote sensing, ground-based field measurements, and one, two and three-dimensional hydrologic and hydraulic modeling of natural phenomena on Earth and Mars. Collecting and processing remote sensing data will provide the fluvial channel physical properties needed for the hydrologic and hydraulic models, which then will be verified by extensive field mapping of the fluvial channels at two Earth analogue study areas, in the Glacial Lake Missoula paleoflood zone and in Iceland. A unique technique for deriving the hydraulic property of surface roughness, based on bedrock thermal inertia and conductivity, will be tested. The objective of this work is to estimate the mean flow velocity, peak discharge and power needed to create the jökulhlaup-type fluvial channels and geomorphic features on Earth in order to apply these models to similar channels on Mars. Secondly, the goal is to establish quantitatively the amount of water needed on Mars to create these features given a gravitational constant less than half that of the Earth's. This research will provide new quantitative insight into the hydrologic and geologic history of Mars.The results of this work will convey quantitative information about the amount of water needed to sculpt the fluvial landforms on Mars and provide a significant datapoint to its geologic and hydrologic past. This research will provide key insight into the mechanisms that created the massive outflow channels on Mars and how climate change may have influenced these processes. Similarly, hydrologic and hydraulic modeling of catastrophic flow regimes and the interactions between surface and subsurface water sources at Earth analogues sites, particularly at those areas most influenced by glacial processes, will provide a viewpoint to the processes that may occur due to our own climate change. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.

对行星体的地球类似物的研究主要用于检验有关现象可能与地球上类似的现象的假设。这项博士学位论文研究使用地球类似物来检验以下假设：火星上大量的河流通道及其观察到的地貌特征是由地表水流和被冰要素层覆盖的地下水的爆发组合而成的。这些类型的喷发被称为“Jökulhlaup”，这是冰岛语术语，该术语描述了突然从冰川后面或下方释放大量水。地球表面上也有类似的位置，包括华盛顿东部的切尼 - 帕卢伊斯（Cheney-Palouuse）的scablands（与米苏拉冰川湖相关）和冰岛Vatnajökull冰川的JökulsááFjöllum通道。这些地球类似物是通过地质过去的Jökulhlaup-type爆发地板形成的，因此应提供对火星上的过程的见解，其中源贝斯的大小不足以创建河流和地貌特征，尤其是考虑到较低的行星压力压力。这项研究涵盖了太空传播远程灵敏度，基于地面的现场测量以及一项，两维自然现象在地球和火星上的水平和水解建模。收集和处理遥感数据将提供水文和水解模型所需的河道物理特性，然后通过在冰川湖米苏拉湖古富洛德湖和冰岛的两个地球模拟研究区域和冰岛的两个地球模拟研究区域的河流通道进行广泛的现场映射来验证。将测试一种基于基岩的热惯性和电导率来得出表面粗糙度的水解特性的独特技术。这项工作的目的是估计地球上创建Jökulhlaup-type型河流和地球形态特征所需的平均流速，峰值排放和功率，以便将这些模型应用于火星上的类似通道。其次，目标是定量建立火星上所需的水量来创建这些特征，鉴于引力常数小于地球的一半。这项研究将为MAR的水文和地质历史提供新的定量见解。这项工作的结果将传达有关雕刻火星上河流所需的水量的定量信息，并为其地质和水文过去提供了重要的数据点。这项研究将为创造火星上大量渠道渠道的机制以及气候变化如何影响这些过程的机制提供重要的见解。类似地，灾难性流动方案的水文和水解建模以及地球类似物站点的表面与地下水源之间的相互作用，尤其是在受冰川过程影响最大的地区，将为我们自身的气候变化而可能发生的过程提供一个观点。作为博士学位论文研究改进奖，该奖项还将提供支持，使有前途的学生能够建立强大的独立研究职业。