Volcanic gases were collected from several locations. Gases collected at sea along the submerged part of active eruptive fissure were dominantly carbon dioxide and gases from cooling submerged lava flows were about 70 percent hydrogen. (Richard & James, 1983) Poisonous gas was found at low areas on the eastern part of Vestmannaeyjar. A wall was constructed between the vent and town to divert the gas, and a long trench was excavated for the steam to escape. However, none of these measures were completely effective. (Richard & James, 1983)