CO2 Degassing relate to 2021 Nyiragongo Volcan éruption

The Nyiragongo volcano in the western part of the African Rift has the deep fractures that a facilite the upwelling of gases before and after the eruption, especially carbon dioxide (CO2 ). This paper presents the behaviour of carbon dioxide before and after the eruption on 22 May 2021. The Nyiragongo volcano eruption begun on 22 May 2021 at 18:15 LT (Local Time) in Goma. The lava flowed from the flanks of the volcano in two directions, one flow coming to a halt in the northeastern suburbs of Goma, The other flow cut off one kilometre of the national road 4 linking Goma to Butembo, a major regional road vital for suplying Goma town is frequently mentioned causing 32 victims, incorporation of volatile gases to the atmosphere, the destruction of 17 villages in the territory of Nyiragongo and crack in Goma and Gisenyi. The Nyiragongo Volcano is infamous for its extremely fluid lava that flows like water when the lava lake flows. This which is monitored by the scientific community of the Goma Volcanological Observatory (G .V. O), and the lava lake produces a huge amount of gas. CO2 is heavier than air, asphyxiating, and lethal at concentrations greater from 15%. The present paper shows the variation of CO2 near the volcano in monitoring sites to study the behavior one Month before the eruption, the CO2 showed an increasing trend in some sites and a few Months after the eruption we observed a slight decrease of 3% in all the CO2 monitoring sites. Nyiragongo is an important contributor of CO2 and SO2 to the troposphere. This 2021 eruption is similar to the one of 17 January 2002, which caused about 100 people’s death of and the evacuation of several people. The deadliest eruption of Nyiragongo was in 1977, when more than 600 people died. Post-eruption seismic activity was characterised by a large number of earthquakes of magnitude 3.5 or more. A few earthquakes of magnitude greater than 3.5 have been recorded by global seismic networks (USGS), the strongest of which had a magnitude of 5.2 in 2002. Compared to other eruptions that Nyiragongo volcano has experienced, the seismic activity before the eruption of 22 May 2021 was not too alarming. This is because there were no strong earthquakes (greater than or equal to 3.5) that preceded the eruption a few months before, as had been noted in previous eruptions. After the eruption, exceptional seismic activity was noticed. Many earthquakes of magnitude greater than or equal to 3.5 were recorded by the local seismographic network. These earthquakes were felt, the strongest having a magnitude of 5.2