Unchartered fault through outcrop study by using simple structure from motion technique in seismicaly active area

Abstract

Structure from motion (SfM) is a photogrammetric method used to reconstruct 3-Dimensional (3D) surfaces from the displacement of the camera in between several 2-dimensional photographs. This method can produce sparse and dense point clouds from which high-resolution surface models such as digital surface models and digital terrain models are obtained. SfM is not restricted to topographic surfaces, it also can be used to model various ground objects at different scales such as trees, buildings, outcrops and any other structure that can be photographed with an ordinary camera. Among this myriad of possibilities, the present contribution focuses on the reconstruction of 3D outcrop models, as they can become digital archives of geological and seismic activity, especially in countries where landscape remodeling activity and mining are important. Outcrop is a vertical exposure of particular rock formation. By knowing the characteristics of the outcrop, we can understand the reservoir characteristics and important stratigraphic information. Also, we can take more attention on microstructural information for both slope instability and seismic characteristics analysis. Thus, although SfM is relatively new in geoscience, this study will provide the usage of the SfM technique to support the outcrop analysis to obtain important micro-structure information of the outcrop. Further, this data was used to support the seismic susceptibility assessment in a very complex geological structure area.