Development of a glacial abrasion rule for landscape-evolution models

景观演化模型冰川磨损规则的发展

• 批准号: 2017185
• 负责人: Lucas Zoet
• 金额: $ 20.94万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2017185&HistoricalAwards=false
• 关键词: Development; glacial; abrasion; rule; landscape

Glacial landscapes are sculpted by the ice that slides above them. The constant flow of ice wears away at the underlying bedrock, eroding it through time. The rates and patterns of this wear stem in part from a process called abrasion, which results from sediment entrained in basal ice being pressed into the underlying rock and drug along by the glacier. A number of theories have been proposed to estimate abrasion rates, which depend on a multitude of parameters. In order to accurately model the evolution of glacial landscapes, a mathematical “abrasion law” is needed that accurately captures the physics relevant to abrasion. The form of the abrasion law is difficult to determine beneath real glaciers because their beds are often inaccessible and the controlling factors are difficult to measure in the field. Further compounding these difficulties is the fact that abrasion rates are miniscule and therefore require decades or centuries to pass before the eroded volume is measurable. The goal of this project is to develop a mathematical relationship that describes the physics of glacial abrasion using a novel set of laboratory instruments, so that it can be implemented in numerical landscape evolution models. In the laboratory, conditions can be controlled and measured with the precision needed to accurately determine the abrasion law. The project will support a graduate and an undergraduate student from UW-Madison and provide training for underrepresented students from the College of Menominee Nation.A large-diameter ring shear device and a direct shear device at UW-Madison will be used to slide debris-laden ice at the pressure melting point over rock beds that vary in shape and composition. The striations produced by abrasion will be analyzed using a white light interferometer capable of measuring the volume of eroded material down to 10-18 cubic meters. With the ability to measure these miniscule volumes, the sliding experiments can be conducted in relatively short timeframes (less than one month each) and still generate sufficient abraded volume to determine the abrasion law. Using these instruments, an abrasion law will be developed that relates the rate of erosion to independent variables, such as sliding speed, basal melting, bed shape, debris hardness, and debris concentration.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

冰川景观是由冰的恒定流动在下面的基岩上的，部分是由于磨损的过程，这是由于在基础冰中被压在冰上的过程。冰川在多种参数上，以使冰川景观的演变为数学，这是一种与磨损形式相关的数学“磨损定律”该领域的困难是很小的事实，并且可以衡量的是侵蚀量的数百年来。该项目将支持UW-Madison的Andergraduaduaduder andud，并为Menominee Nation学院的学生提供培训。指向形状变化的岩石床，由beanyazy产生的曲线使用白光干涉仪，能够侵蚀的材料下降10-18立方米。驯服（每个月少于一个月），并且仍会产生少量的磨损定律，以触发对自变量的侵蚀率，例如滑动速度，基础熔化，床形，碎屑硬度和内度碎片浓度。 NSF的BEATEND被认为值得支持Thendation的重新功绩和更广泛的影响审查标准。

项目成果

A power-based abrasion law for use in landscape evolution models

用于景观演化模型的基于功率的磨损定律

• DOI: 10.1130/g50673.1
• 发表时间: 2023
• 期刊: Geology
• 影响因子: 5.8
• 作者: Hansen, D.D.;Brooks, J.P.;Zoet, L.K.;Stevens, N.T.;Smith, L.;Bate, C.E.;Jahnke, B.J.
• 通讯作者: Jahnke, B.J.