History of Gas in Geothermal Fluids, Krafla, Northeast Iceland

From 1871 to 1975 there was little change in the gas composition of Krafla fluids. Parts of the system were affected by magmatic gas during the Krafla fires of 1975-1984. In some parts the gas composition has gradually come back to the pre-1975 levels, but gas concentrations have risen elsewhere, apparently due to heating in parts that were not directly affected by volcanic gas.