Studies of gas emission from volcanoes

Studies of the gas emissions from the Nyiragongo volcano in the Republic of Congo

Mt. Nyiragongo is a very active volcano located in eastern DR Congo close to the border of Rwanda. The city of Goma with about 1000000 inhabitants is located less than 20 km from the volcano. The area is politically very unstable; with hundreds of thousands of refugees from the civil war in the area and in nearby Rwanda. In 2002 a flank eruption caused rapid lava flows (up to 100 km/h) that destroyed about 20% of the city. Besides the high direct threat of the volcano to the population, the volcano is one of the strongest sources of volcanic gases in the world with an SO₂ emission of 5000 - 50000 ton/day. In addition high amounts of HCl and HF are abundant in the plume. The population and vegetation downwind the volcano is strongly affected both directly by the toxic gases, and indirectly by acid rain and contaminated drinking water. Since 2003 Chalmers has been involved in development and installation of instruments for quantification of the total gas emissions from Nyiragongo, with the primary aim to improve volcanic risk assessment.

In this project we wish to extend our work by studying the regional impact that emissions from Mt. Nyiragongo have on human health and the environment. A mesoscale meteorological model has been set up over the region, to produce high resolution meteorological data. These data are used together with the emission data to drive a dispersion model. In this way we will estimate the geographical and temporal distribution of near-surface concentrations of gases. Finally, the surface concentration will be compared with regional health data to study the impact of the emissions.

Collaboration with Bo Galle, Chalmers

Contacts: Anna Rutgersson