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.

在洋中脊动力学中，一个长期存在的争议是，快速扩张脊下的上升流是片状的，沿轴方向有相对均匀的岩浆供应，还是更三维的，在板块中心附近有类似底涌流的上升流，在浅岩浆室水平和/或由较低的地壳韧性流沿轴方向的熔体横向重新分布。UNDERSHOOT实验旨在通过绘制岩浆从地幔到地壳的输送模式，沿着Siqueiros和Clipperton断裂带之间的东太平洋隆起的整个变形边界段的长度来解决这个问题。数据的质量是值得进一步分析的重要问题。地壳厚度模型将采用改进的算法进行改进，使实验中收集的所有数据能够同时建模。对莫霍转捩和上地幔性质的认识将得到提高。将发展改进的地幔和下地壳低速带结构沿轴变化模型。