A new perspective on fractures - using unmanned aerial vehicles to analyze tectonic structures in high resolution

• Main Author: Weismüller, Christopher
• Other Authors: Reicherter, Klaus, Urai, Janos
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: RWTH Aachen University 2021
• Subjects: info:eu-repo/classification/ddc/550; Bristol Channel; Iceland; UAV; drone; fractures; photogrammetry
• Online Access: https://publications.rwth-aachen.de/record/819297; https://publications.rwth-aachen.de/search?p=id:%22RWTH-2021-04963%22

Fractures are ubiquitous structures in the brittle crust of the Earth and occur at a variety of scales. Better understanding them contributes to a wide field of implications such as water and geothermal energy supply, natural hazard assessment, paleostress analysis, basin modelling, hydrocarbon exploration or reservoir geology. Numerous methods are used to study the evolution and geometry of fractures. These methods consist of classical ground-based field work and mapping, large scale remote sensing studies based on satellite data, analog models and numerical models, or combinations of different methods. In this work, I present fracture analyses based on high-resolution digital elevation models (DEMs) and orthorectified mosaics that I created using unmanned aerial vehicle (UAV) photogrammetry techniques. The objective of using these novel methods is to bridge the gap between classical ground-based field work and analyses using aerial and satellite imagery for the investigation of the structure and geometry of fractures and fracture networks. Photogrammetric models containing real world data serve as benchmark for analog models of faults and associated fractures and are used to develop and utilize workflows for the digital extraction and interpretation of wide-ranging sets of fracture data. To investigate the structure and evolution of massively dilatant faults on Iceland, I created a comprehensive dataset of fractures associated with dilatant faults. I mapped the fractures and extracted geometrical measurements based on surface models. Furthermore, the models and results were used as benchmark for analog models. The identification of surface structures in the real-world data and the corresponding structures in the analog models aid the prediction of the subsurface structure of massively dilatant faults based on their surface expressions. I show that massively dilatant faults can be described as different endmembers of their surface manifestation with respect to their opening width and vertical offset. All ...