Improved 3D Coastal Outcrop Models Using Multiple UAV Acquisitions: Example of the Hikurangi Margin, New Zealand
Résumé
The investigation of outcrop analogues using Unmanned Aerial Vehicle (UAV) has become increasingly popular to improve the understanding of subsurface heterogeneity. Although seismic data offer an invaluable method to characterize the stratigraphic architecture of deep-water systems and therefore help unlock their reservoir potential, the scale of observations cannot capture detailed vertical extent of the sediment distribution and the related processes responsible for the deposits. This work uses a combination of photographic data acquired from a UAV using Ground Control Points, and traditional fieldwork data to better characterize the gravity-driven systems of the Hikurangi subduction wedge (North Island, New Zealand). Their best onshore expressions are found along the coastline: a challenging working environment which evolves every day leading to multiple acquisitions (tides will affect wind variation and wave action, impacting sand coverage; sun and clouds will impact light exposure). It is therefore essential to adapt the way we acquire and model data to ensure that all the information are gathered into one single comprehensive model. Our study proposes to expand on the traditional Structure from Motion workflow to account for such settings and help create more accurate models. We will present this approach applied to three different coastal outcrops. \textcopyright EAGE 2019.