Collaborative Research: Unraveling distributed deformation during early-stage rifting in the Western and Southwestern African Rifts

合作研究：揭示非洲西部和西南部裂谷早期裂谷期间的分布式变形

• 批准号: 2039962
• 负责人: Matthew Pritchard
• 金额: $ 14.58万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2039962&HistoricalAwards=false
• 关键词: Collaborative; Research; Unraveling; distributed; deformation

Rifting, which leads to the breakup of continents and the formation of new ocean basins, is one of the fundamental processes in plate tectonics. East Africa is the prime example of present-day continental rifting. While a number of studies have yielded important insights in the older, more developed rifts in northern East Africa, there are major gaps in our knowledge of how rifting begins and develops due to sparse data in the younger Western and Southwestern rift systems. In particular, there is significant uncertainty about how far ground deformation related to early-stage rifting extends across the region and to what extent deformation may occur without earthquakes. This project will use a combination of ground deformation data from GNSS/GPS data, Synthetic Aperture Radar Interferometry (InSAR), and permanent seismometers to measure and investigate the kinematics of early-stage rifting across the Western and Southwestern rifts. Results will improve our understanding of fundamental tectonic processes and earthquake hazard estimates in the region. The project will provide student research opportunities at both the undergraduate and graduate levels, develop international research collaborations, and contribute to capacity building in science and technology through outreach in secondary schools in the USA and Africa and providing opportunities in training in data processing and analysis through in-country workshops and visits to US research institutions.The overall goal of this project is to test existing models of how rifting is distributed across uplifted and faulted areas of Central Africa surrounding the Western and Southwestern segments of the East African Rift and determine what component of the active rifting is aseismic. To achieve this goal, geodetic measurements, including campaign and continuous GNSS and InSAR, in this under-studied area will be increased. This will provide improved constraints on the tectonic strain field across multiple temporal and spatial scales. Catalogue and regional seismic source data will be combined and then Kostrov summation comparisons of seismic and geodetic observations across the region will be performed in order to evaluate the amount and spatial variation in aseismic deformation and to constrain lithospheric properties. The new geodetic and seismic results will be used to generate an improved model of the kinematics of deformation in the region that is consistent with other geological and geophysical data and can be used to evaluate current models of strain localization in cold, strong lithosphere.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

裂谷作用导致大陆分裂和新洋盆的形成，是板块构造的基本过程之一。 东非是当今大陆裂谷的典型例子。 虽然许多研究对东非北部更古老、更发达的裂谷产生了重要的见解，但由于年轻的西部和西南部裂谷系统的数据稀疏，我们对裂谷如何开始和发展的认识存在重大差距。 特别是，与早期裂谷相关的地面变形在该地区延伸了多远，以及在没有地震的情况下变形会发生到什么程度，存在很大的不确定性。 该项目将结合使用 GNSS/GPS 数据、合成孔径雷达干涉测量 (InSAR) 和永久地震仪的地面变形数据来测量和研究西部和西南裂谷早期裂谷的运动学。 结果将提高我们对该地区基本构造过程和地震灾害估计的理解。 该项目将为本科生和研究生提供研究机会，发展国际研究合作，并通过在美国和非洲的中学进行推广，促进科学技术能力建设，并通过以下方式提供数据处理和分析培训机会：国内研讨会和访问美国研究机构。该项目的总体目标是测试现有模型，了解东非裂谷西段和西南段周围的中部非洲隆起和断层区域如何分布裂谷，并确定裂谷的组成部分活跃裂谷是抗震。 为了实现这一目标，将增加这一研究不足领域的大地测量，包括活动和连续 GNSS 和 InSAR。 这将为跨多个时间和空间尺度的构造应变场提供改进的约束。 将目录和区域震源数据结合起来，然后对整个区域的地震和大地测量观测进行科斯特罗夫求和比较，以评估地震变形的量和空间变化并约束岩石圈特性。 新的大地测量和地震结果将用于生成该区域变形运动学的改进模型，该模型与其他地质和地球物理数据一致，并可用于评估寒冷、强岩石圈中应变局部化的当前模型。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。