DOI: 10.7914/sn/7g_2021
title: Collaborative Research: Constraining transient magma intrusion processes in the Nyiragongo-Kivu continental rift zone

description: On 22 May 2021, following an eruption along the southern flank of Nyiragongo volcano in the Democratic Republic of Congo (DRC), a graben began opening further southward across the border into Rwanda, and beneath the northern half of Lake Kivu, bounding Rwanda and the DRC. Satellite imagery suggests at least a 10 km-long segment opened about seven meters by the end of May, in a region that included the northern portion of the lake. However, seismicity recorded primarily by a local network in the DRC shows substantial activity continuing another 10-15 km southward below the lake, and structures were damaged onshore in Rwanda. Seismicity from a prior event in 2002 interpreted as a dike intrusion continued for approximately eight months and while the current local seismicity has calmed, aseismic opening may continue for some time. This proposal aims to further investigate the magma-fault interactions achieving rift opening during and following the 2021 sequence, and to further image crustal structure to understand the consequences of dike intrusion to active and time-averaged deformation. The project will maintain a temporary continuous network of 7 GPS/GNSS stations and 9 seismometers, including 2 that were installed during the intrusion event, to both capture the detailed time history and kinematics of the rifting event, and give additional information for correcting atmospheric and other noise in satellite-based SAR Interferometry. New and permanent seismic and 25 magnetotelluric imaging sites will enable determination of lateral variations in physical properties of the crust, and the degree of magmatic modification. Intellectual Merit: The project will collect detailed geodetic, seismic, and magnetotelluric information to examine the time history and extent of continued deformation associated with the 2021 Lake Kivu rifting event, as well as cumulative effects of 12 My of magmatism and extension. 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. The research performed through this proposal will fund fieldwork for 2 US-based Rwandan and 1 Kenyan graduate students and 4 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 semi-permanent continuous GNSS and seismicity data will be available globally, and colleagues in Rwanda will be provided with access to software for rapid analysis for emergency response. This work in the region will assist with real-time monitoring, hazard assessment, and mitigation, and contribute to the training of at least 7 African scientists. A Tulane REU student will be recruited from a cohort of formerly incarcerated women.