ISOS Miniproposal



September 2019

Bettina's and Christoph's work is about processing and interpretation 3D seismic and sediment image techniques. During their doctorate they came up with an amazing research idea for which they applied for an ISOS Miniproposal. Read more about their scientific work and experiences below.

 

GRAPA – Geological fracture pattern analyses using UAV-based photomontages and photogrammetric digital elevation models

Our doctoral projects started in November 2016 with the main goal of processing and interpreting 3D seismic and sediment imaging techniques along with direct sampling to investigate fluid pathways in seafloor sediments. Our work is part of the Strategies for Environmental Monitoring of Marine Carbon Capture and Storage (STEMM-CCS) project whose objective it is to constrain the effects of CO2 leakage on the marine environment. As an extension of the previous work, which was conducted primarily in the marine realm, we set out to answer open questions that arose during our doctoral projects and wrote an ISOS Miniproposal.
Based on available literature, we proposed to further investigate an area named Pobiti Kamani and the Beloslav Quarry, both in close vicinity to Varna, Bulgaria. There, carbonate-cemented pipes are remnants of a methane seep system of the lower Eocene (~47.5-56 Ma). In particular, we used drone-based photogrammetry to map and quantify fracture networks in these outcrops, to use these as onshore analogues to help derive the geometries, hydraulic properties of the fracture networks and transfer this knowledge to the marine realm. Furthermore, we were doing hands-on geology with field mapping, sampling and drilling of the pipes and their surrounding with help from Ben J. Callow (University of Southampton), who participated in this young-researchers project.

                                       

Our preliminary results show very high-quality and high-resolution data of both, the geological and geophysical data sets. The photogrammetric models have a resolution of less than 3 cm/pixel and the ground control points should give us a geodetic accuracy of less than 1 m. The sampling with a hand drill and a diamond-coated drill bit was very successful and we retrieved high-quality samples which will be analyzed by Ben J. Callow in Southampton. In combination, this integrated data set will improve the understanding of the formation processes of the carbonate-cemented pipes and their nature. Moreover, it will help to answer the open questions regarding the fracture geometries, spatial distribution of the pipes and subsequently infer hydraulic properties.

We are thankful for the opportunity, the ISOS Miniproposal gave us, to not only complement our scientific profiles, but also to allow us to learn important soft skills such as administrative, financial and time management of a project, teamwork, networking and project reporting. We thank ISOS and especially Avan for making this project possible. This project was successful, because of the great support we received from Felix Gross at the Kiel University, who lent his drone and software to overcome shortage in funding, but also because of our colleagues here at GEOMAR (Mark Schmidt, Jörg Bialas, Jens Karstens, Christian Berndt), the colleagues from the Institute of Oceanology (Atanas Vassilev, Petar Petsinski) and the director of the Nature Park "Zlatni Pyassatsi" Ms. Darinka Sarova.

picture credits: Bettina Schramm and Christoph Böttner