摘要:
Two geochemists say that measuring gas ratios in geothermal waters that have surfaced from deep within the earth can help pinpoint the hottest spot in a geothermal reservoir. The technique avoids inserting long thermometers or drilling deep holes into the earth.When water falls as rain or flows in rivers and lakes, it picks up from the atmosphere such gases as nitrogen, oxygen, and argon, explain David Norman, assistant geophysics professor at the New Mexico Institute of Mining and Technology, and Carl Bernhardt, a graduate student. As the water sinks into the earth and heats up, most of the atmospheric gases bubble off. Then, the water absorbs other gases such as helium and carbon dioxide from the surrounding rocks and soil. When this hot water rises to the surface by convection, Norman told Eos, it cools rapidly but retains its underground gases. By calculating the ratios of carbon dioxide to methane in the water that has risen to the surface, the temperature of the water when it was deep within the earth can be estimated, the geochemists say. This new method could help tap with precision economic geothermal reservoirs.
ISSN:0002-8606
DOI:10.1029/EO062i042p00706-01
年代:1981
数据来源: WILEY