The Kinematic Evolution of the Galapagos Triple Junction

伍兹霍尔海洋研究所的研究人员正在分析最近在加拉帕戈斯群岛三重连接点收集的多波束测深数据。总体目标是了解：1)东太平洋隆起附近的科科斯-纳斯卡裂谷的大传播应力是否控制了其北部和南部瞬时裂谷的位置和稳定性；2)大约100万年前有利于加拉帕戈斯微板块形成的条件。研究团队将：1)对现有的所有原始多波束数据进行整理，并与近期采集的原始数据进行整合；2)分析加拉帕戈斯微板块形成前Cocos-Nazca裂谷南部的地形模式，评价裂缝相互作用模型的适用性；3)破译了Dietz深裂谷的形成、东太平洋隆起附近大型火山几乎同时形成以及加拉帕戈斯微板块形成的控制因素；4)了解微孔板内的地形模式。洋脊-洋脊-洋脊三联结是三个洋中扩张中心的交汇处。洋脊-洋脊-洋脊三联点处的海底地形表明，这一背景下的主要岩石圈板块正在发生内部变形。观测到的变形尚不清楚，但可以提供关于覆盖地球的岩石圈板块如何形成的重要信息。S表面对应力有响应。最近对加拉帕戈斯群岛三结区进行了调查，提供了一个无与伦比的海洋三结区视图，并提供了解决几个悬而未决的问题的机会，这些问题是关于岩石圈对主要板块交汇和边界迅速变化的压力的反应。该项目解决了主要岩石圈板块在压力下如何变形以及板块边界如何发展的突出大规模问题。对加拉帕戈斯群岛三结区的研究也可能为了解岩浆在板块下上升并在地表喷发可能如何改变岩石圈应力提供洞见。此外，加拉帕戈斯微板块在该地区的形成和生长对洋中脊的动力学具有重要意义。

Researchers from the Woods Hole Oceanographic Institution are analyzing of multibeam bathymetry data that were recently collected at the Galapagos triple junction. The overarching goals are to understand: 1) whether the stresses associated with the large propagating Cocos-Nazca Rift near the East Pacific Rise controls the location and stability of transient rifting to its north and south; 2) the conditions that favored the formation of the Galapagos microplate about 1 million years ago. The research team will: 1) compile all existing raw multibeam data and integrate them with the recently collected raw data; 2) analyze topographic patterns south of the Cocos-Nazca Rift, before the initiation of the Galapagos microplate, to assess the applicability of the crack interaction model; 3) decipher the controls on the initiation of Dietz Deep Rift, the nearly concurrent formation of a large volcano near the East Pacific Rise, and the establishment of the Galapagos microplate; 4) understand topographic patterns within the microplate.A ridge-ridge-ridge oceanic triple junction is where three mid-ocean spreading centers meet. Seafloor topography at ridge-ridge-ridge oceanic triple junctions indicates that the major lithosphere plates in this setting are deforming internally. The observed deformation is not well understood, but can provide important information on how the lithosphere plates that cover Earth?s surface respond to stresses. The recently surveyed Galapagos triple junction region, provides an unparalleled view of an oceanic triple junction, and presents the opportunity to address several outstanding questions about the response of the lithosphere to stresses in this setting where the major plates meet and their boundaries are rapidly changing. This project addresses the outstanding large-scale problem of how major lithospheric plates deform under stress and how plate boundaries develop. The study of the Galapagos triple junction region may also provide insight into how magma rising beneath the plates and erupting on the surface might change the lithospheric stresses. In addition, the initiation and growth of the Galapagos microplate at this region has important implications for the dynamics of mid-ocean ridges.