Sheppard, D.S.; Mroczek, E.K. 2002 Measuring diffuse CO2 flows to the atmosphere from geothermal systems . Lower Hutt: Institute of Geological & Nuclear Sciences. Institute of Geological & Nuclear Sciences science report 2002/14 38 p.
Abstract: The flow of CO2 from geothermal systems to the atmosphere has rarely been measured, and probably never adequately assessed, yet it is of increasing relevance in today’s climate. The exploitation of geothermal energy releases the gas and causes disturbances to the natural flows, but this effect needs to be quantified, both during the term of the exploitation and in the longer term. In 1992, attempts were made to measure the flows from three sites above geothermal systems in the Taupo Volcanic Zone, using equipment which has since been recognised as inadequate. However, the data has been examined, reduced and analysed, and gives important information on the range of fluxes at different sites, and on the variability of the flows in response to atmospheric variables. The range of fluxes ascribable to geothermal CO2 emissions ranged from 0.5 to 3 g/m2 at Wairakei and Tauhara and up to 15-25 g/m2 at Reporoa. However as the equipment was effectively a negative pressure system, these must be regarded as broad estimates. (auth)