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

智力上的优点。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。中美洲俯冲带是研究流体对弧和下伏地幔楔和俯冲板片的影响的理想场所，因为它的输入和输出是变化的。现有的地球化学研究表明，广泛的变化程度板水化沿着这弧，最大和最小板的贡献，岩浆生成本地化尼加拉瓜和哥斯达黎加，分别。 地球化学研究表明，板块流体的贡献也存在于萨尔瓦多和危地马拉，但减少到西北部。地球物理研究表明，尼加拉瓜下方存在高度的板片蛇纹化和流体释放，而科斯塔下方的情况相对较少，但弧的其余部分在地质学上的特征不佳--主要是因为萨尔瓦多和危地马拉下方的板片没有得到很好的解析。本研究将利用所有现有的地震数据，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部分，以便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危地马拉至哥斯达黎加的地方地震网络提供的其他数据合并，这些数据从未被合并用于研究整个中美洲俯冲带。这项研究将通过使用双差速度层析成像和重新定位方法，获得中美洲俯冲带内板片和地幔楔的更广泛的地震图像。拟议的项目将主要支持一名年轻女科学家（锡拉丘兹）的专业发展，她以前没有得到NSF的支持。锡拉丘兹将参加威斯康星大学麦迪逊分校的三角洲计划，整合研究，教学和学习。三角洲支持当前和未来的教师在科学，技术，工程和数学在他们的学生学习的改善。

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.