Collaborative Research: Constraining transient magma intrusion processes in the Nyiragongo-Kivu continental rift zone

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On 22 May 2021, a very large and destructive volcanic eruption occurred along the southern flank of Mount Nyiragongo in the Democratic Republic of Congo (DRC), killing at least 30 people and causing substantial threat and damage near and in the city of Goma, affecting approximately a million people. Early satellite imagery showed that a segment of an underground magmatic rift began opening further southward and across the border into Rwanda, damaging homes and farmland, and creating further risk as it continued below the northern half of Lake Kivu, bounding Rwanda and the DRC. Continued rifting beneath the lake presents an additional risk of causing a massive and rapid release of carbon dioxide that could gravely threaten nearby populations (a similar event in Lake Nyos in western Africa killed over 1700 people in 1986). This project will investigate the interactions between magmatic movement in the subsurface and earthquake faulting during and following the 2021 sequence to aid in developing a stronger understanding of the mechanics and behavior of rifting and the hazards they pose in such environments. To do this the project will address key scientific questions to develop a better understanding of the magmatic and faulting evolution over time and gaining insight into some of the critical processes that govern changes in eruptive behavior. The project will create detailed images of earthquake activity along active faults, as well as magmatic material pathways using geophysical tools. The geologic processes learned here will aid in understanding this and future potentially dangerous rifting events elsewhere in East-Africa and in the US. The research performed through this proposal will fund fieldwork for one Kenyan and two US-based Rwandan graduate students and four Rwanda-based students enrolled in graduate studies at the East African Institute for Fundamental Research (EAIFR). The research and educational partnerships with EAIFR, University of Rwanda, and Goma Volcano Observatory will help to foster improved collaborations between US and central-African scientists, extractive industry, emergency managers and diplomats from the Kivu rift region, and help to inform planners regarding natural hazards. The work in the region will assist with real-time monitoring, hazard assessment and mitigation, and contribute to the training of at least seven African scientists. A Tulane student will be recruited from a cohort of formerly incarcerated women.The project will collect detailed land-deformation, seismic, and electromagnetic signals information to examine the time-history and extent of continued deformation following the Lake Kivu rifting event, as well as cumulative effects of 12 million years of deformation and magmatic buildup. The project will maintain a temporary continuous network of 7 GPS/GNSS stations (for land-deformation measurement) and 9 seismometers, including 2 that were installed during the intrusion event. The new and permanent seismic stations and 25 magnetotelluric imaging sites (electromagnetic measurements) will enable determination of lateral variations in physical properties of the crust, and the degree of magmatic modification. The project too will collect and evaluate satellite-based Synthetic Aperture Radar information to further constrain deformation over time. The data will aid in kinematic and physics-based modeling of the evolution of the young continental rift system. The information gained here will help to illuminate the process of magma migration in these environments, their interaction with the fractured, intruded, and heated crust, and their dynamic relationship with induced earthquake activity. Data from the GPS/GNSS and seismic networks will be available globally, and colleagues in Rwanda will be provided with access to software for rapid analysis for emergency response. This project is supported by the Geophysics and Petrology/Geochemistry Programs in the Division of Earth Sciences.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.