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

俯冲带的构造板块之间的相互作用导致了世界上已知的最大地震(8级)以及慢滑事件(SSE)的发生。SSE可能发生在几天到几年的时间里，人们感觉不到。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。在新西兰东海岸俯冲带，SSE每1-2年发生一次，为了更好地了解SSE，许多研究都集中在这一地区。在新西兰边缘的SSE地区收集了一个三维地震数据集，该项目将对这些数据进行处理，以了解该地区的断层系统和流体流动系统，以及这些系统对SSE的影响。这一结果将有助于评估俯冲带的地震和海啸危害。该项目支持对两名早期职业科学家和一名研究生的培训。缓滑事件(SSE)涉及持续数天至数年的断层上的瞬时无地震滑动。在世界各地的许多俯冲带中都观察到了SSE，但控制这种类型滑移的物理机制仍然知之甚少。在新西兰东海岸近海的Hikurangi边缘，有充分证据的SSE每1-2年在俯冲巨型逆冲的浅部(约2-15公里深)发生一次。这为通过详细的地震成像和地震属性测量来检查促成SSE生成的结构和水文地质条件提供了一个理想的机会。一组科学家在Hikurangi北部边缘14.7x60公里的勘测区内获得了3D地震体。这一三维数据集，具有完全的覆盖率和极好的质量，显示出巨大的潜力来揭示沿板块界面的条件以及这些条件的发展。3D体积将经过最先进的3-D叠前时间和深度偏移处理，以成像尽可能高水平的结构细节，同时保留反射特征。这些数据将被分析和解释，以调查边缘的流体流动和构造发展。这一裁决反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.