Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations

合作研究：罗斯冰架对波浪引起的振动的动态响应

• 批准号: 1246151
• 负责人: Peter Bromirski
• 金额: $ 74.1万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1246151&HistoricalAwards=false
• 关键词: Collaborative; Research; Dynamic; Response; Ross

Bromirski/1246151This award supports a project intended to discover, through field observations and numerical simulations, how ocean wave-induced vibrations on ice shelves in general, and the Ross Ice Shelf (RIS), in particular, can be used (1) to infer spatial and temporal variability of ice shelf mechanical properties, (2) to infer bulk elastic properties from signal propagation characteristics, and (3) to determine whether the RIS response to infragravity (IG) wave forcing observed distant from the front propagates as stress waves from the front or is "locally" generated by IG wave energy penetrating the RIS cavity. The intellectual merit of the work is that ocean gravity waves are dynamic elements of the global ocean environment, affected by ocean warming and changes in ocean and atmospheric circulation patterns. Their evolution may thus drive changes in ice-shelf stability by both mechanical interactions, and potentially increased basal melting, which in turn feed back on sea level rise. Gravity wave-induced signal propagation across ice shelves depends on ice shelf and sub-shelf water cavity geometry (e.g. structure, thickness, crevasse density and orientation), as well as ice shelf physical properties. Emphasis will be placed on observation and modeling of the RIS response to IG wave forcing at periods from 75 to 300 s. Because IG waves are not appreciably damped by sea ice, seasonal monitoring will give insights into the year-round RIS response to this oceanographic forcing. The 3-year project will involve a 24-month period of continuous data collection spanning two annual cycles on the RIS. RIS ice-front array coverage overlaps with a synergistic Ross Sea Mantle Structure (RSMS) study, giving an expanded array beneficial for IG wave localization. The ice-shelf deployment will consist of sixteen stations equipped with broadband seismometers and barometers. Three seismic stations near the RIS front will provide reference response/forcing functions, and measure the variability of the response across the front. A linear seismic array orthogonal to the front will consist of three stations in-line with three RSMS stations. Passive seismic array monitoring will be used to determine the spatial and temporal distribution of ocean wave-induced signal sources along the front of the RIS and estimate ice shelf structure, with the high-density array used to monitor and localize fracture (icequake) activity. The broader impacts include providing baseline measurements to enable detection of ice-shelf changes over coming decades which will help scientists and policy-makers respond to the socio-environmental challenges of climate change and sea-level rise. A postdoctoral scholar in interdisciplinary Earth science will be involved throughout the course of the research. Students at Cuyamaca Community College, San Diego County, will develop and manage a web site for the project to be used as a teaching tool for earth science and oceanography classes, with development of an associated web site on waves for middle school students.

该奖项支持的项目旨在通过实地观测和数值模拟，发现一般情况下，特别是罗斯冰架（RIS）上的海浪引起的振动如何能够(1)推断冰架力学特性的时空变化，(2)从信号传播特性推断体弹性特性，(3)确定RIS对远距锋面观测到的次重力（IG）波强迫的响应是作为应力波从锋面传播，还是由IG波能量穿透RIS空腔“局部”产生。这项工作的智力价值在于，海洋重力波是全球海洋环境的动力要素，受海洋变暖和海洋和大气环流模式变化的影响。因此，它们的演变可能会通过机械相互作用和潜在的基底融化来驱动冰架稳定性的变化，而基底融化反过来又会反馈给海平面上升。重力波引起的信号在冰架上的传播取决于冰架和亚冰架水腔的几何形状（如结构、厚度、裂缝密度和方向）以及冰架的物理性质。重点将放在观测和模拟RIS在75至300秒周期内对IG波强迫的响应。由于IG波不会受到海冰的明显抑制，因此季节性监测将有助于深入了解RIS对这种海洋学强迫的全年响应。这个为期3年的项目将包括为期24个月的连续数据收集，跨越RIS的两个年度周期。RIS冰锋阵列覆盖与罗斯海地幔结构（RSMS）协同研究重叠，提供了有利于IG波定位的扩展阵列。冰架部署将由16个站点组成，配备宽带地震仪和气压计。RIS锋面附近的三个地震台站将提供参考响应/强迫函数，并测量整个锋面的响应变化。与前线正交的线性地震阵将由三个站和三个RSMS站组成。被动地震阵列监测将用于确定沿RIS前端的海浪诱发信号源的时空分布，并估计冰架结构，高密度阵列用于监测和定位裂缝（冰震）活动。更广泛的影响包括提供基线测量，以便能够探测未来几十年的冰架变化，这将有助于科学家和决策者应对气候变化和海平面上升带来的社会环境挑战。一名跨学科地球科学的博士后学者将参与整个研究过程。圣地亚哥县Cuyamaca社区学院的学生将为该项目开发和管理一个网站，作为地球科学和海洋学课程的教学工具，并为中学生开发一个有关海浪的网站。

项目成果

Seasonal and spatial variations in the ocean-coupled ambient wavefield of the Ross Ice Shelf

• DOI: 10.1017/jog.2019.64
• 发表时间: 2019-09
• 期刊: Journal of Glaciology
• 影响因子: 3.4
• 作者: M. Baker;R. Aster;R. Anthony;J. Chaput;D. Wiens;A. Nyblade;P. Bromirski;P. Gerstoft;R. Stephen

Heterogeneous upper mantle structure beneath the Ross Sea Embayment and Marie Byrd Land, West Antarctica, revealed by P-wave tomography

• DOI: 10.1016/j.epsl.2019.02.013
• 发表时间: 2019-05
• 期刊: Earth and Planetary Science Letters
• 影响因子: 5.3
• 作者: A. White-Gaynor;A. Nyblade;R. Aster;D. Wiens;P. Bromirski;P. Gerstoft;R. Stephen;S. Hansen;T. Wilson;I. Dalziel;A. Huerta;J. Paul Winberry;S. Anandakrishnan

Identifying Ocean Swell Generation Events from Ross Ice Shelf Seismic Data

从罗斯冰架地震数据中识别海洋涌浪生成事件

• DOI: 10.1175/jtech-d-19-0093.1
• 发表时间: 2019
• 期刊: Journal of Atmospheric and Oceanic Technology
• 影响因子: 2.2
• 作者: Hell, Momme C.;Cornelle, Bruce D.;Gille, Sarah T.;Miller, Arthur J.;Bromirski, Peter D.
• 通讯作者: Bromirski, Peter D.

Tidal and Thermal Stresses Drive Seismicity Along a Major Ross Ice Shelf Rift

• DOI: 10.1029/2019gl082842
• 发表时间: 2019-06
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: S. Olinger;B. Lipovsky;D. Wiens;R. Aster;P. Bromirski;Z. Chen;P. Gerstoft;A. Nyblade;R. Stephen

Unsupervised Deep Clustering of Seismic Data: Monitoring the Ross Ice Shelf, Antarctica

无监督地震数据深度聚类：监测南极洲罗斯冰架

• DOI: 10.1029/2021jb021716
• 发表时间: 2021
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: Jenkins, II, William F.;Gerstoft, Peter;Bianco, Michael J.;Bromirski, Peter D.
• 通讯作者: Bromirski, Peter D.