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.

大洋中脊动力学中长期存在的争议是，快速扩张的洋脊下方的上升流是呈片状，沿轴方向岩浆供给相对均匀，还是呈三维状，在段中心附近呈底辟状上升流，熔体沿水平方向横向重新分布。轴位于浅岩浆室水平和/或通过下地壳、延性流。 UNDERSHOOT 实验旨在解决这一问题，方法是沿着西凯罗斯和克利珀顿断裂带之间的东太平洋隆起变换边界段的整个长度绘制从地幔到地壳的岩浆输送模式。 数据质量是仍然需要进一步分析的重要问题。 地壳厚度模型将通过采用改进的算法来完善，该算法允许同时对实验中收集的所有数据进行建模。 对莫霍面转变和上地幔特性的理解将得到提高。 将开发地幔和下地壳低速区结构沿轴变化的改进模型。