Processing, interpretation and analysis of the NZ3D seismic data to investigate fault property controls on slow-slip along the Hikurangi megathrust

处理、解释和分析 NZ3D 地震数据，以研究断层属性对沿 Hikurangi 巨型逆冲断层的慢滑移的控制

• 批准号: 1901645
• 负责人: Nathan Bangs
• 金额: $ 135.42万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1901645&HistoricalAwards=false
• 关键词: Processing; interpretation; analysis; NZ3D; seismic

Interactions between tectonic plates at subduction zones are responsible for generating the world's largest known earthquakes (magnitudes 8+) as well as slow-slip events (SSEs). SSEs may take place over days to years, and are not felt by people. What controls the occurrence of SSEs and how they are related to large subduction zone earthquakes is not known. At the subduction zone along the east coast of New Zealand SSEs occur every 1-2 years and many studies have focused on this region to get a better understanding of SSEs. A 3-dimensional seismic data set has been collected in a region of SSEs along the New Zealand margin and this project will process these data to understand the fault systems and fluid flow systems in the region and the impact of these systems on SSEs. The results will aid in the assessment of earthquake and tsunami hazards at subduction zones. The project supports the training of two early career scientists and a graduate student.Slow-slip events (SSEs) involve transient aseismic slips on a fault that last days to years. SSEs have been observed in a number of subduction zones worldwide, yet the physical mechanisms that control this type of slip remain poorly understood. At the Hikurangi margin offshore the east coast of New Zealand, well documented SSEs recur every 1-2 years at the shallow portion (~2-15 km depth) of the subduction megathrust. This provides an ideal opportunity to examine the structural and hydrogeological conditions that contribute to the generation of SSEs through detailed seismic imaging and seismic attribute measurements. A team of scientists acquired a 3-D seismic volume within a 14.7 x 60 km survey area on the northern Hikurangi margin. This 3-D dataset, with complete coverage and excellent quality, shows great potential to reveal the conditions along the plate interface and the development of these conditions. The 3-D volume will be processed with state-of-the-art 3-D pre-stack time and depth migration to image the highest possible level of structural detail while preserving reflection characteristics. The data will be analyzed and interpreted to investigate fluid flow and tectonic development of the margin.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.

俯冲带的构造板块之间的相互作用是产生世界上最大的已知地震（8级以上）以及慢滑事件（SSE）的原因。SSE可能会持续几天到几年，人们不会感觉到。是什么控制了SSE的发生，以及它们与大型俯冲带地震的关系尚不清楚。在新西兰东海岸沿着的俯冲带，SSE每1-2年发生一次，许多研究都集中在这一地区，以更好地了解SSE。 在新西兰边缘沿着的一个SSE区域收集了三维地震数据集，本项目将处理这些数据，以了解该区域的断层系统和流体流动系统以及这些系统对SSE的影响。研究结果将有助于评估俯冲带的地震和海啸灾害。 该项目支持两名早期职业科学家和一名研究生的培训。慢滑事件（SSE）涉及断层上持续数天至数年的短暂地震滑动。在世界范围内的许多俯冲带都观察到了SSE，但控制这种类型滑动的物理机制仍然知之甚少。在新西兰东海岸的Hikurangi边缘，在俯冲巨型逆冲断层的浅部（~2-15 km深度），每隔1-2年就会发生一次有据可查的SSE。 这提供了一个理想的机会，通过详细的地震成像和地震属性测量来检查有助于生成SSE的结构和水文地质条件。一个科学家小组在希库朗吉北方边缘14.7 x 60公里的勘探区内获得了三维地震体。这个三维数据集，具有完整的覆盖范围和优良的质量，显示了巨大的潜力，揭示条件沿着板界面和这些条件的发展。将用最先进的三维叠前时间和深度偏移对三维体积进行处理，以便在保留反射特征的同时，尽可能对结构细节进行成像。该奖项反映了NSF的法定使命，并已被认为是值得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的支持。

项目成果

Slow slip along the Hikurangi margin linked to fluid-rich sediments trailing subducting seamounts

• DOI: 10.1038/s41561-023-01186-3
• 发表时间: 2023-06-05
• 期刊: NATURE GEOSCIENCE
• 影响因子: 18.3
• 作者: Bangs, Nathan L.;Morgan, Julia K.;Fry, Bill
• 通讯作者: Fry, Bill