Geohazards and ecosystem dynamics in proximity to active earthquake faults - Mara River Basin, Tanzania

• Applicant: Privatdozent Dr. Simon Kübler
• Subject Area: Geology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 540549900

Since ancient times, earthquake faults have benefitted people by channeling water and nutrients to the surface and creating strategic topographic retreats. Similarly, repeated slip along earthquake faults can benefit ecosystems and modify animal and human subsistence patterns. Yet, despite these benefits, research has traditionally, understandably, focused on threats and hazards of seismic activity. Here, we attempt to redress this balance, using recent advantages in remote sensing and combined geological and geo-pedochemical field analysis tools enable significant improvements in understanding the complex interface between fault zones and ecosystems. We propose to carry out an interdisciplinary study in the Mara River Basin (MRB) in northern Tanzania, located in the interior of the Victoria microplate between the eastern and western branch of the East African Rift System. The MRB is located in proximity to the rapidly urbanizing Lake Victoria region for which the potential seismic hazard is poorly known. Further, the region offers a unique diversity of plant and animal species and our preliminary data suggest that the effects of tectonic activity is an important yet understudied agent of ecosystem stability by providing long-term supply of water and soil nutrients to this region. We aim to study in detail the Pleistocene-to-recent activity of fault structures in the region and the interplay between tectonic surface faulting and processes at the bedrock-soil interface as well as their impact on the Serengeti-Mara ecosystem. We will focus on analysis of the Isuria-Utimbara Fault Zone (IUFZ), which forms the northern boundary of the MRB and represents a previously unknown active fault structure, and an important feature influencing the soils and vegetation of the Serengeti-Mara ecosystem. Our proposed methods include detailed tectono-geomorphic and geo-pedological mapping using remote sensing and field-based techniques to decipher the Quaternary-to-recent faulting activity of the IUFZ and additional fault structures in the MRB. We will perform time-series analysis of soil and vegetation dynamics combining multi- and hyperspectral satellite data with multispectral UAV data. We will collect rock, soil and vegetation samples and determine their physicochemical characteristics using a field XRF analyzer. With this we aim to explore the spatial distribution of vital soil nutrients as well as the decadal-to-seasonal variations in the ecological characteristics of the MRB, with respect to tectonic boundary conditions. Our proposed research project has the potential to contribute to a better understanding of (A) the geotectonic foundation on which the MRB is built upon, (B) the general role of tectonic faulting in influencing ecosystem processes in climatically sensitive regions and (C) the potential seismic hazard in one of Africas fastest growing urban regions.

• DFG Programme: Research Grants
• International Connection: Tanzania, USA
• Co-Investigators: Professorin Dr. Eileen Eckmeier; Dr. Michaela Schauer
• Cooperation Partners: Ryan Gold, Ph.D.; Professor Dr. Revocatus Machunda; Dr. Alfred Said