Next-generation 3D imaging of the on- and off-axis mantle and crustal magmatic systems at the Endeavour segment

Endeavour 段的轴上和离轴地幔和地壳岩浆系统的下一代 3D 成像

• 批准号: 1634786
• 负责人: Douglas Toomey
• 金额: $ 18.11万
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1634786&HistoricalAwards=false
• 关键词: Next; generation; 3D; imaging; off

Next-generation 3D imaging of the on- and off-axis mantle and crustal magmatic systems at the Endeavour segmentThe global mid-ocean ridge seafloor spreading system accounts for ~85% of Earth's annual magma budget, dominating the mass and energy exchange between the solid earth and its hydrosphere. Magmatic systems beneath spreading centers drive high- and low-temperature hydrothermal activity that modulates the long-term chemistry of the oceans, hydrates the crust and mantle, supports novel ecosystems whose study has altered our view of the origin of life on Earth, and deposits valuable mineral resources. The fundamental unit of the global mid-ocean ridge system is a ridge segment. Within a single ridge segment there are systematic variations in tectonic, volcanic and hydrothermal processes. Ridge segments vary systematically with spreading rate with three basic types: fast-, intermediate- and slow-spreading. Understanding what governs spreading-center segmentation is to understand the fundamental unit of a globe encircling system. The broader significance and importance of the project will be to use next-generation seismic imaging methods to constrain the structure of the magmatic system beneath a well-studied mid-ocean ridge segment. The study site is located off the west coast of the US and is a focus area for international research with a seafloor observing node as part of Neptune Canada, which is allied with the US Ocean Observatory Initiative. The project will support a junior female researcher and a graduate student as part of the research. There is also significant international collaboration with United Kingdom researchers on innovative new seismic data analysis techniques.Understanding mass and energy transfer at mid-ocean ridges requires mapping mantle and crustal magmatic systems and their relationship to hydrothermal and tectonic processes. The location, size, shape, and longevity of magmatic systems depend on factors such as the patterns of melt delivery from the mantle to the crust, melt ascent pathways, and perhaps most importantly, the efficiency of heat removal. Hydrothermal flow patterns are in turn determined by the distribution of heat sources and crustal permeability. To understand these linkages, the project will more accurately map mantle and crustal magmatic systems at the Endeavour segment both on- and off-axis. The primary objectives are to determine (i) what controls the characteristics and distribution of crustal magma bodies both on- and off-axis, and (ii) how hydrothermal heat transfer interacts with and shapes crustal magmatic systems. These objectives will be accomplished by applying 3D anisotropic travel time tomography and 3D full-waveform inversion (FWI) to wide-angle seismic data from a seismic tomography experiment (ETOMO) at the Endeavour. Segment-scale compressional wave velocity images will be generated to map the distribution of crustal magma bodies, the pattern of melt transport from the shallow mantle through the lower crust, and to infer spatial variations in crustal temperature and melt fraction. The study is sited at the Endeavour Ridge where a wealth of previous results, high-quality seismic data, and recent advances in seismic imaging methods can be brought together at a segment where there are strong contrasts between the segment center and ends.

努力段的全轴和地壳岩浆系统的下一代3D成像全球中大海山脊海底海底散布系统占地球年度MAGMA预算的〜85％，占地质量和能量交换占固体地球及其水分球之间的质量和能量交换。 扩散中心下方的岩浆系统驱动了高温和低温的水热活动，从而调节了海洋的长期化学，滋润地壳和地幔，支持新的生态系统，其研究改变了我们对我们对地球生命起源的看法，并沉积了有价值的矿产资源。 全球中山山脊系统的基本单元是山脊部分。在单个山脊段中，构造，火山和水热过程有系统的变化。 山脊段随着三种基本类型的扩散率而系统地变化：快速，中间和缓慢分布。了解哪些规定的传播中心细分是为了了解地球包围系统的基本单位。该项目的更广泛的意义和重要性将是使用下一代地震成像方法来限制岩浆系统的结构，下方经过良好的中境山脊段下方。 研究地点位于美国西海岸，是国际研究的重点领域，海底观察节点是加拿大海王星的一部分，该节点与美国海洋天文台倡议结盟。作为研究的一部分，该项目将支持初级女性研究人员和研究生。与英国研究人员有关创新的新地震数据分析技术也有重大的国际合作。理解中脊的质量和能量转移需要绘制地幔和地壳岩浆系统及其与水热和构造过程的关系。岩浆系统的位置，大小，形状和寿命取决于诸如从地幔到外壳融化的融化方式，融化的上升途径，也许最重要的是，去除热量的效率等因素。水热流图又取决于热源的分布和地壳渗透性。为了了解这些联系，该项目将更准确地绘制努力段和离轴的努力段的地幔和地壳岩浆系统。主要目标是确定（i）在轴上和外轴上控制地壳岩浆物体的特性和分布，以及（ii）水热热传递如何与地壳岩层岩浆系统相互作用。这些目标将通过将3D各向异性旅行时间断层扫描和3D全波倒置（FWI）应用于努力的地震层析成像实验（ETOMO）的广角地震数据。将生成段尺度的压缩波速度图像，以绘制地壳岩浆体的分布，从浅层地幔穿过下层地壳的熔体传输模式，并在地壳温度和熔体分数中推断空间变化。这项研究位于努力脊中，在该阶段，可以在段中心和目的之间存在强烈对比的细分市场中，可以将大量的先前结果，高质量的地震数据和最新的地震成像方法的进步汇总在一起。

项目成果

Seismic Imaging and Physical Properties of the Endeavour Segment: Evidence that Skew Between Mantle and Crustal Magmatic Systems Governs Spreading Center Processes

奋进段的地震成像和物理特性：地幔和地壳岩浆系统之间的偏差控制着扩散中心过程的证据

• DOI: 10.1029/2018gc007978
• 发表时间: 2019
• 期刊: Geosystems
• 作者: Arnoux, G. M.;Toomey, D. R.;Hooft, E. E. E.;Wilcock, W. S. D.
• 通讯作者: Wilcock, W. S. D.

Upper Crustal Vp / Vs Ratios at the Endeavour Segment, Juan de Fuca Ridge, From Joint Inversion of P and S Traveltimes: Implications for Hydrothermal Circulation

胡安德富卡海岭奋进段的上地壳 Vp / Vs 比率，来自 P 和 S 走时的联合反演：对热液循环的影响

• DOI: 10.1029/2018gc007921
• 发表时间: 2019
• 期刊: Geosystems
• 作者: Kim, Eunyoung;Toomey, Douglas R.;Hooft, Emilie E. E.;Wilcock, William S. D.;Weekly, Robert T.;Lee, Sang‐Mook;Kim, Young Hee
• 通讯作者: Kim, Young Hee

Segmentation of mid-ocean ridges attributed to oblique mantle divergence

地幔倾斜分歧导致的大洋中脊分段

• DOI: 10.1038/ngeo2745
• 发表时间: 2016
• 期刊: Nature Geoscience
• 影响因子: 18.3
• 作者: VanderBeek, Brandon P.;Toomey, Douglas R.;Hooft, Emilie E.;Wilcock, William S.
• 通讯作者: Wilcock, William S.

Next-generation seismic experiments – II: wide-angle, multi-azimuth, 3-D, full-waveform inversion of sparse field data

下一代地震实验≫二：稀疏场数据的广角、多方位、三维、全波形反演

• DOI: 10.1093/gji/ggv513
• 发表时间: 2016
• 期刊: Geophysical Journal International
• 影响因子: 2.8
• 作者: Morgan, Joanna;Warner, Michael;Arnoux, Gillean;Hooft, Emilie;Toomey, Douglas;VanderBeek, Brandon;Wilcock, William
• 通讯作者: Wilcock, William

Near-axis crustal structure and thickness of the Endeavour Segment, Juan de Fuca Ridge: Crustal Structure at Endeavour Segment

奋进段的近轴地壳结构和厚度，胡安德富卡海岭：奋进段的地壳结构

• DOI: 10.1002/2016gl068182
• 发表时间: 2016
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Soule, Dax;Wilcock, William S.;Toomey, Douglas R.;Hooft, Emilie E.;Weekly, Robert T.
• 通讯作者: Weekly, Robert T.