Seismological Models and Seismicity Patterns in the Kivu Rift and Virunga Volcanic Province (D.R. Congo / Rwanda)

The Kivu Rift is located in the bordering region of the Democratic Republic of Congo and Rwanda, in the Western branch of the East African Rift. The active volcanoes Nyamulagira and Nyiragongo in the Virunga Volcanic Province threaten the city of Goma and neighbouring agglomerations. Urbanisation in in the direct vicinity of the volcano undergoes sustained rapid growth, and the region counts 1 million inhabitants today. The successive eruptions of Nyiragongo which occurred in 1977, 2002 and 2021 caused major disasters and casualties. Moreover, destructive earthquakes can also affect the region, as it was the case in 2002 in Kalehe (Mw 6.2) along the western shore of Lake Kivu, or in 2008 in Bukavu (Mw 5.9), south of Lake Kivu.

Between 2013 and 2022, the first dense real-time telemetered broadband seismic network in the Kivu Rift region (KivuSNet) was gradually deployed in the frame of several research projects and was fully operational with a sufficient station coverage (>10 stations) since October 2015. Due to the fundamental importance of monitoring the seismicity in this region, substantial efforts were made for setting up this network permanent with real-time data acquisition, which thus rapidly became the main seismic network of the Goma Volcano Observatory for daily routine monitoring work.

This contribution will present the lessons learned from more than 6.5 years (October 2015 – June 2022) of continuous seismic monitoring in the the Kivu basin as well as the current status of seismological information derived from these data, including a robust 1D seismic velocity model and calibrated local magnitude scale for the Kivu Rift region. The complete seismicity catalogue (volcanic and tectonic events) has been relocated and the main seismic patterns will be discussed with a special emphasis on how this new knowledge can help the Goma Volcano Observatory in improving its monitoring tasks.