CAREER: Convergence of Space Geodesy in Plate Boundary Research and Geoscience Education

该项目研究了斜向会聚和应变分配的运动学和力学，以及山脊碰撞对上板块变形俯冲带的地球动力学影响，以更好地了解弧前地体的形成。这项研究将新的和现有的GPS数据、地震数据(地震位置和质心矩张量解)和地质观测与数值模型相结合，以：1)估计板间逆冲断层和弧前走滑断层上耦合的强度和空间变异性；2)确定弧前运动的速率；3)分析与应变分配和山脊碰撞有关的力。研究的重点是中美洲南部(科科斯-纳斯卡-加勒比海板块：巴拿马)和南美洲北部(纳斯卡-南美洲板块：厄瓜多尔)的两个汇聚边缘。在中美洲南部，科科斯板块汇聚是垂直的，科科斯山脊与边缘相撞。这里没有发育边缘平行的弧前走滑断裂，认为弧前向西北和东南方向的运动是由山脊碰撞驱动的。在南美洲北部，纳斯卡板块的会聚是倾斜的，卡内基山脊与边缘相撞。边缘平行的弧前走滑断裂适应了北安第斯地块的北东向运动。将在巴拿马和厄瓜多尔建立全球定位系统网络，以便更好地限制科科斯板块和纳斯卡板块与中美洲地峡(加勒比板块)和南美洲板块相互作用造成的地表变形的运动学。这一职业奖项的教育部分：1)通过开发六个板块构造电子表格模块来提高地球科学的量化素养，其有效性将得到评估；2)通过UNAVCO学生固体地球科学研究体验项目和宾夕法尼亚州立大学高级本科生研究体验项目为本科生提供国际研究和教育经验；3)为研究生提供国际研究和教育经验；4)形成关于板块边界的新课程的基础。俯冲带板块边界释放最大数量的弹性能量，产生大地震和毁灭性的海啸。板块在俯冲带的相互作用可能是复杂的，在板块之间的会聚与板块边缘不是垂直的地方，以及在海底海脊相撞的地方。在这些情况下，盖覆板中的运动可以分为巨型逆冲运动和走滑运动。这项研究的目的是在巴拿马和厄瓜多尔的两个例子中通过组合使用GPS数据来确定控制这种行为的力，这将改进运动向量，并通过建模来约束所起作用的力。学生将通过使用数据的课堂活动和国际研究经验参与该项目。这项研究的结果将有助于了解中美洲的地震危害。这项研究项目得到了地球科学部的构造、教育和人力资源项目以及国际科学和工程办公室美洲项目的支持。

This project investigates the kinematics and mechanics of oblique convergence and strain partitioning and the geodynamic affects of ridge collision on upper plate deformation subduction zones to gain a better understanding of the formation of fore-arc terranes. This study integrates new and existing GPS data, seismic data (earthquake locations and centroid moment tensor solutions), and geologic observations with numerical models to: 1) estimate the magnitude and spatial variability of coupling on interplate thrust and fore-arc strike-slip faults; 2) determine the rate of fore arc motion; and 3) conduct an analysis of the forces associated with strain partitioning and ridge collision. The study focuses on two convergent margins, southern Central America (Cocos-Nazca-Caribbean plates: Panama) and northern South America (Nazca-South America plates: Ecuador). In southern Central America, Cocos plate convergence is orthogonal and the Cocos Ridge collides with the margin. There is no well-developed margin parallel fore-arc strike-slip fault here and it has been suggested that fore-arc motion to the northwest and southeast is driven by ridge collision. In northern South America, Nazca plate convergence is oblique and the Carnegie Ridge collides with the margin. Margin parallel fore-arc strike-slip faults accommodate northeast motion of the North Andean block. GPS networks will be established in Panama and Ecuador to better constrain the kinematics of surface deformation caused by the interaction of the Cocos and Nazca plates with the Central American isthmus (Caribbean plate) and South American plate. The educational component of this CAREER award : 1) enhances quantitative literacy in the geosciences through the development of six plate tectonics spreadsheet modules whose effectiveness will be assessed; 2) provides international research and education experiences for undergraduate students through the UNAVCO Research Experience in Solid Earth Science for Students and the Penn State University Center for Advanced Undergraduate Studies Experience programs; and 3) provides international research and education experiences for graduate students; 4) forms the basis for new courses on plate boundaries.Subduction zone plate boundaries release the greatest amount of elastic energy producing great earthquakes and devastating tsunamis. The interaction of plates at subduction zones can be complex where convergence between plates is not orthogonal to the plate margin and where submarine ridges collide. In these cases, motion in the overriding plate can be partitioned between megathrust and strike-slip motion. This study aims determine the forces that control this behavior in two examples in Panama and Ecuador through a combined use of GPS data, which will refine the motion vectors, and modeling to constrain the forces at play. Students will be engaged in the project through classroom activities using the data and through international research experiences. The results of this study will assist in understanding earthquake hazards in Central America.This research project is supported by the Earth Sciences Division's Tectonics and Education & Human Resources Programs and the Office of International Science and Engineering Americas Program.