On Saturday 22 May at about 18:30 UTC, Nyiragongo volcano, in the north of Goma city – North Kivu province had an effusive eruption that caused masses of people self-evacuating themselves, retreating to Rwanda. The Goma city authorities responded quickly with an evacuation plan despite the blockage of the main north road (N2) by the lava flow. According to UNICEF report over 150 children have been abandoned by the parents; and 170 children have gone missing as people fled. At least 5000 people have retreated to Rwanda; more than 25,000 in Sake, 25 km north-west of Goma city have been displaced. Despite the complete disruption of social services in Goma city, the subsequent weeks have seen a return of some people to their original homes but to find them completely destroyed. Scores of homeless children around Goma airport have no one to turn to (UNICEF, 23 May 2021). Buhene, Kibumba and Kibatshi have so far witnessed five deaths.
It is feared underground magma is flowing towards Lake Kivu with carbon dioxide (CO2) and methane sipping through volcanic vents which could cause a suffocating cloud of gas thus leading to a limnic eruption that would be lethal to human and aquatic life in the vicinity of the lake. Owing to this fear, the Goma city authorities have advised residents to evacuate the city thus leaving it deserted. As a result of a limnic eruption, a landslide, an earthquake and a rise in the water temperature of the lake are likely to occur.
With about 475m (1,558ft) deep, Lake Kivu is estimated to contain an invisible and odorless 300 cubic km of carbon dioxide (CO2) denser than air. If faced with a big underneath volcanic explosion, shores of Lake Kivu would be over flooded. This kind of catastrophe has occurred before at Lake Nyos in Cameroon with very tragic consequences whereby an estimated 18000 people in the surrounding villages were asphyxiated.
According to Goma Volcano Observatory (OVG), three scenarios are most likely:
- A limnic eruption is a likely possibility;
- At the altitude 3,500 m high Mountain Nyiragongo, another eruption is eminent. If this is to occur a new lava flow southwards towards Goma would be inevitable; despite a 10 km distance north of Goma city, the speed of the lava flow is comparable to the speed of a car making it difficult to outrun.
- And thirdly, the methane release from Lake Kivu makes the already complex scenario a total disaster. If released in huge amounts, methane is inflammable thus making Goma unsafe.
Recent high-resolution INSAR radar images revealed that the ground south of the volcano has risen by several centimeters during or since the eruption. The vertical displacement is more vivid in the vicinity of Goma city, where several cracks in the ground are highly noticeable. This triggers fears that the formation of a new dike – or lava-filled fissure – that could give way and culminate into a second, potentially catastrophic flank eruption