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: 2039961
• 负责人: Julie Elliott
• 金额: $ 28.88万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing 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=2039961&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.

裂谷作用是板块构造的基本过程之一，它导致大陆的分裂和新洋盆的形成。 东非是现今大陆裂谷作用的最好例子。 虽然一些研究在东非北方较古老、较发达的裂谷中取得了重要的见解，但由于在较年轻的西部和西南部裂谷系统中数据稀少，我们对裂谷如何开始和发展的认识存在重大差距。 特别是，有很大的不确定性有多大的地面变形有关的早期裂谷延伸到整个地区，在何种程度上变形可能会发生没有地震。 该项目将综合利用全球导航卫星系统/全球定位系统数据、合成孔径雷达干涉测量法（干涉合成孔径雷达）和永久地震仪提供的地面变形数据，测量和调查西部和西南部裂谷早期断裂的运动学。 研究结果将提高我们对该地区基本构造过程和地震危险性估计的理解。 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，通过在美国和非洲的中学开展外联活动，促进科学和技术能力建设，并通过以下方式提供数据处理和分析方面的培训机会：国家讲习班和访问美国研究机构。该项目的总体目标是测试现有的模型，以了解裂谷如何分布在中部非洲周围的隆起和断层地区。东非裂谷的西部和西南部部分，并确定什么组成部分的活动裂谷是aseacutrient。 为实现这一目标，将增加这一研究不足地区的大地测量，包括活动和连续全球导航卫星系统和干涉合成孔径雷达。 这将在多个时间和空间尺度上对构造应变场提供更好的约束。 将把目录和区域地震源数据结合起来，然后对整个区域的地震和大地测量观测进行Kostrov求和比较，以评价地震变形的数量和空间变化，并限制岩石圈的性质。 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相一致，并可用于评估目前的冷、热环境中应变局部化模型，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查进行评估，被认为值得支持的搜索.