Collaborative Research: Constraining Mantle Flow, Melt Supply, and Lower Crustal Structure Between the Clipperton and Siqueiros Fracture Zones from a Seismic Undershoot Experiment

合作研究：通过地震下冲实验约束克利珀顿和西凯罗斯断裂带之间的地幔流动、熔体供应和下地壳结构

• 批准号: 0118597
• 负责人: Douglas Toomey
• 金额: $ 8.9万
• 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: 2001
• 资助国家: 美国
• 起止时间: 2001-10-15 至 2005-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0118597&HistoricalAwards=false
• 关键词: Collaborative; Research; Constraining; Mantle; Flow

A long-standing controversy in mid-ocean ridge dynamics is whether upwelling beneath fast spreading ridges is sheet-like with a relatively uniform magma supply along axis, or more three-dimensional with diapiric-like upwelling near segment centers and lateral redistribution of melt along axis at shallow magma chamber levels and/or by lower crustal, ductile flow. The UNDERSHOOT experiment was designed to address this problem by mapping the pattern of magma delivery from the mantle to the crust along the entire length of a transform bounded segment of the East Pacific Rise between the Siqueiros and Clipperton fracture zones. The quality of the data are the important issues that remain warrant further analyses. Models of crustal thickness will be refined by employing improved algorithms that allow all data collected in the experiment to be modeled simultaneously. Understanding of the properties of the Moho transition and uppermost mantle will be improved. Improved models of along axis variations in the structure of the mantle and lower crust low velocity zones will be developed.

大洋中脊动力学中一个长期存在争议的问题是，快速扩张的海脊之下的上升流是沿轴线相对均匀的岩浆供应的片状上升，还是更三维的上升，在分段中心附近呈底辟状上升，并在浅层岩浆室水平沿轴线横向重新分配熔体和/或通过下地壳韧性流动。欠冲实验旨在通过绘制沿东太平洋隆起Siqueiros和Clipperton断裂带之间转换边界段的整个长度从地幔到地壳的岩浆输送模式来解决这一问题。数据的质量仍然是需要进一步分析的重要问题。地壳厚度的模型将通过采用改进的算法进行改进，允许同时对实验中收集的所有数据进行建模。对莫霍面转变和最上地幔性质的理解将得到改善。将开发改进的地幔和下地壳低速带结构沿轴变化的模型。