November 2011 eruption

ERUPTION ALERT – November 2011 eruption of Nyamulagira
Information report n°3 – 12th November, 2011

Eruption summary

On 6th November 2011, 5:55 PM (UTC+2), Nyamulagira volcano has started to erupt after two days of intense seismic activity. This eruption is located ± 12 km east-northeast of the Nyamulagira crater, close to one of the 1989 eruptive sites. The previous eruption of this volcano occurred 22 months earlier, in January 2010.

Information from lava flow modelling

The eruptive site was visited by scientists of the Goma Volcano Observatory on Nov. 11th allowing preliminary descriptions and GPS location.

Based on these parameters and the best available topography, simulation of lava flows invasion probability was calculated. Such simulation helps assess the possible paths that the lava flow could follow and thus detect the possible threat for the population and infrastructures. Simulations were performed using the VORIS model (Felpeto et al., 2007), which calculate the probability of lava flow invasion based on 3 parameters: topography, lava flow length and thickness. We present here the result for a 20 km long and 3 m thick lava flow. The simulation was performed on the SRTM DEM.

The result shows high probability of lava flow invasion towards north along two main paths. Both paths could affect the road that links the RN2 (Goma-Rutshuru road) to Tongo (Fig. 1 and 2). The most eastern path could affect a part of the Kalengera village. According to the MODVOLC thermal monitoring (, The lava flow could already cross maximum 10 to 12 km northward (Fig. 3).

IMPORTANT: Please, be aware that this simulation is strongly dependent of the input parameters. In the present situation, the currently active lava flow path does not represent a threat for the population.

Figure 1 – Probability of invasion by lavas (log) for a ±20 km long and 3 m thick lava flow (5000 iterations). (c) B. Smets, RMCA, 2011

Figure 2 – Main possible paths suggested by the lava flow simulation presented in Figure 1. (c) B. Smets, RMCA, 2011

Figure 3 – Probability of invasion by lavas (log) for a ±20 km long and 3 m thick lava flow (5000 iterations). The MODVOLC hotspots (red squares) seem to indicate that the lava is currently flowing northward, inside the Virunga National Park, towards the road Kalengera-Tongo. (c) B. Smets, RMCA, 2011