Testing Models of Magma Movement along the East Pacific Rise Using Combined Geoditic and Numerical Experiments

使用组合大地测量和数值实验测试沿东太平洋海隆的岩浆运动模型

• 批准号: 0426575
• 负责人: Spahr Webb
• 金额: $ 68.55万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-10-15 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0426575&HistoricalAwards=false
• 关键词: Testing; Models; Magma; Movement; along

Abstract (0426575) - CormierThis is a five-year program that will deploy of an array of 20 pressure sensors for four years to monitor magma injection at the NSF-funded RIDGE2000 integrated study site at the East Pacific Rise (9'-10'N). Pressure sensors can successfully detect small (cm) to large (m) vertical motions on mid-ocean ridges. They are also relatively inexpensive and can record data for long periods of time without service. In support of the field program, two modeling efforts will be carried out. The first will interpret measured vertical seafloor displacements that will incorporate the pressure sensor data from the field site. Numerical models of coupled dike intrusion and sill emptying will be developed that include algorithms that take into account the rheological structure of the seafloor at the study site. The second set of models will examine the feasibility of using repeat microbathymetric surveys to constrain surface deformation patterns across a section of a plate boundary. Scientific objectives include discrimination between the two competing models of magma delivery along fast-spreading mid-ocean ridges, the first being where melt is supplied nearly vertically along the ridge axis and the second being where melt is provided at ridge segment centers and propagates toward the segment ends. In the first case, uniform vertical deflections of the pressure sensor network would be expected along the part of a segment cut by a dike, and in the second, pressure sensors would detect significant subsidence near the segment center. Motivation for this study comes from the fact that earthquakes and volcanoes are concentrated on active tectonic plate boundaries, however, nearly 80% of these boundaries occur under the sea and therefore processes occurring there cannot be directly observed. This project, being carried out by researchers at the Woods Hole Institution of Oceanography, will detect, characterize, monitor, and model magma injection episodes along a plate boundary marked by rapid and repeated magma injection events and spreading of the seafloor. Broader impacts of this work include development of a novel magma injection seafloor monitoring system and accompanying modeling tools which have the potential for application to other plate boundaries, student education and training, and making information on the project available to the public and K-12 in a meaningful way through collaboration with the RIDGE2000 outreach program. Development of the bathymetric survey tools also supports the emerging field of marine geodesy.

摘要（0426575）- CormierThis是一个为期五年的计划，将部署一个阵列的20个压力传感器四年来监测岩浆注入在NSF资助的RIDGE 2000综合研究网站在东太平洋隆起（9 '-10' N）。 压力传感器可以成功地探测到大洋中脊上小（厘米）到大（米）的垂直运动。它们也相对便宜，可以在没有服务的情况下长时间记录数据。 为了支持实地项目，将开展两项建模工作。 第一个将解释测量的垂直海底位移，其中将包括来自现场的压力传感器数据。 将开发堤坝侵入和岩床排空耦合的数值模型，其中包括考虑到研究现场海底流变结构的算法。 第二套模型将审查利用重复微测深测量来限制板块边界一段的表面变形模式的可行性。 科学目标包括区分两种竞争模式的岩浆输送沿着快速蔓延的洋中脊，第一个是熔体几乎垂直沿着脊轴和第二个是熔体提供在脊段中心和向段端部传播。 在第一种情况下，压力传感器网络的均匀垂直偏转将被期望沿着被堤坝切割的部分段，并且在第二种情况下，压力传感器将检测到段中心附近的显著沉降。 这项研究的动机来自这样一个事实，即地震和火山都集中在活跃的构造板块边界上，然而，近80%的这些边界发生在海底，因此无法直接观察到那里发生的过程。 该项目由伍兹霍尔海洋学研究所的研究人员进行，将探测、描述、监测和模拟沿着以快速和重复的岩浆注入事件和海底扩张为标志的板块边界的岩浆注入事件。 这项工作的更广泛的影响包括开发一种新的岩浆注入海底监测系统和配套的建模工具，这些工具有可能应用于其他板块边界，学生教育和培训，并通过与RIDGE 2000外展计划合作，以有意义的方式向公众和K-12提供有关该项目的信息。 测深测量工具的开发也有助于新兴的海洋大地测量领域。