MARGINS: Seismic Evidence for Hydration of the Central American Slab: Guatemala Through Costa Rica

边缘：中美洲板块水化的地震证据：危地马拉至哥斯达黎加

• 批准号: 1049533
• 负责人: Ellen Syracuse
• 金额: $ 10.83万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1049533&HistoricalAwards=false
• 关键词: MARGINS; Seismic; Evidence; Hydration; Central

Intellectual merits. The cycling of fluids into and out of subduction zones plays an integral role in the formation of volcanic arcs. The Central American subduction zone is an ideal location for studying the effects of fluid on the arc and underlying mantle wedge and subducted slab due to its varying inputs and outputs. Existing geochemical studies indicate wide variability in degree of slab hydration along this arc, with maximum and minimum slab contributions to magma generation localized beneath Nicaragua and Costa Rica, respectively. Geochemical studies suggest that slab fluid contributions are also present beneath El Salvador and Guatemala, but diminish to the northwest. Geophysical studies are consistent with a high degree of slab serpentinization and fluid release beneath Nicaragua, versus comparatively little beneath Costa, but otherwise the rest of the arc is poorly characterized geophysically - primarily because the slab is not well-resolved beneath El Salvador and Guatemala. The present study will utilize all available seismic data to extend the velocity model developed for Costa Rica and Nicaragua into the northwestern section of the arc, allowing regional analysis of the relation between seismic structure and fluid distribution. Data reported to the International Seismic Centre will be combined with additional data from local seismic networks from Guatemala through Costa Rica, which has never been integrated to study the entire Central American subduction zone. This study will obtain a more extensive seismic image of the slab and mantle wedge within the Central American subduction zone through the use of a double difference velocity tomography and relocation method.Broader Impacts. The proposed project will primarily support the professional development of a young female scientist (Syracuse), who has not has prior NSF support. Syracuse will participate in the UW-Madison DELTA program for Integrating Research, Teaching, and Learning. DELTA supports current and future faculty in science, technology, engineering and math in their improvement of student learning.

知识的优点。流体进出俯冲带的循环在火山弧的形成中起着不可或缺的作用。中美洲俯冲带由于其不同的输入和输出，是研究流体对弧和下伏地幔楔和俯冲板的影响的理想地点。现有的地球化学研究表明，沿这条弧的板块水化程度存在很大差异，板块对岩浆生成的最大和最小贡献分别位于尼加拉瓜和哥斯达黎加下方。地球化学研究表明，在萨尔瓦多和危地马拉地下也有板块流体的贡献，但向西北方向减少。地球物理研究表明，尼加拉瓜下方有高度的板岩蛇纹石化和流体释放，而哥斯达黎加下方相对较少，但除此之外，弧的其余部分在地球物理上的特征很差——主要是因为萨尔瓦多和危地马拉下方的板岩没有得到很好的解析。目前的研究将利用所有可用的地震数据，将为哥斯达黎加和尼加拉瓜开发的速度模型扩展到弧的西北段，从而可以对地震结构和流体分布之间的关系进行区域分析。向国际地震中心报告的数据将与从危地马拉到哥斯达黎加的当地地震网的额外数据结合起来，这些数据从未被纳入对整个中美洲俯冲带的研究。本研究将通过使用双差速层析成像和重新定位方法，获得中美洲俯冲带内的板块和地幔楔的更广泛的地震图像。更广泛的影响。拟议的项目将主要支持一位年轻的女科学家（Syracuse）的专业发展，她之前没有得到过NSF的支持。锡拉丘兹大学将参与威斯康星大学麦迪逊分校的DELTA项目，以整合研究、教学和学习。DELTA支持当前和未来的科学、技术、工程和数学教师改善学生的学习。