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

职业：空间大地测量学在板块边界研究和地球科学教育中的融合

• 批准号: 0955560
• 负责人: Peter LaFemina
• 金额: $ 50.9万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-15 至 2018-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0955560&HistoricalAwards=false
• 关键词: CAREER; Convergence; Space; Geodesy; Plate

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.

本计画研究斜向会聚与应变分配的运动学与力学，以及洋脊碰撞对上板块变形俯冲带的地球动力学影响，以更好地了解弧前俯冲带的形成。本研究整合了新的和现有的GPS数据，地震数据（地震位置和质心矩张量解），地质观测与数值模型：1）估计的规模和空间变化的耦合板间逆冲断层和弧前走滑断层; 2）确定弧前运动的速率;和3）进行分析的力量与应变分配和脊碰撞。研究的重点是两个会聚边缘，中美洲南部（科科斯-纳斯卡-加勒比板块：巴拿马）和南美洲北方（纳斯卡-南美洲板块：厄瓜多尔）。在中美洲南部，科科斯板块聚合是正交的，科科斯海脊与边缘碰撞。没有发育完善的边缘平行弧前走滑断层，弧前向北西和南东方向的运动是由脊碰撞驱动的。在南美洲的北方，纳斯卡板块的会聚是倾斜的，卡内基海岭与边缘碰撞。边缘平行弧前走滑断层适应北安第斯地块的东北运动。将在巴拿马和厄瓜多尔建立全球定位系统网络，以更好地限制科科斯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。该职业奖的教育部分：1）通过开发六个板块构造电子表格模块（其有效性将被评估），提高地球科学的定量素养; 2）通过UNAVCO学生固体地球科学研究经验和宾夕法尼亚州立大学高级本科生研究中心经验计划，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）为板块边界的新课程奠定基础。俯冲带板块边界释放出最大的弹性能量，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，在那里，板块之间的会聚不垂直于板块边缘，海底洋脊发生碰撞。在这些情况下，在覆盖板块的运动可以划分为巨型逆冲断层和走滑运动。这项研究的目的是确定在巴拿马和厄瓜多尔的两个例子中控制这种行为的力量，通过结合使用GPS数据，这将细化运动矢量，并建模以约束发挥作用的力量。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灾害。这项研究项目得到了地球科学司的构造学和教育人力资源计划以及国际科学和工程美洲计划办公室的支持。