Natural Changes in Unexploited High-Temperature Geothermal Areas in Iceland

Abstract

Geothermal areas differ and the effects of exploitation on their environment are also very variable. According to Icelandic law an environmental impact assessment is required for a planned power plant, as well as a comparison of alternative power production possibilities for the selection of the environmentally most favourable one. To be able to forecast possible changes following the exploitation of a geothermal field the extent of natural changes occuring within the area with time needs to be known. Monitoring of the field in question is thus needed for several years prior to exploitation. One task of an Icelandic enforcement project on environmental effects of geothermal exploitation has been dedicated to the study of unexploited geothermal areas. The first part of the project was a survey of the status of environmental research in the areas, and as such disclosed an urgent need for increased research. This was followed by the initiation of a monitoring program in selected unexploited geothermal areas. Four areas at different stages of development, Kr?suvÌk, Theistareykir, Torfajˆkull and Kverkfjˆll, have been chosen for monitoring and it is clear that natural changes are quite extensive and depend on factors such as hydrothermal sealing, earthquakes, volcanic activity and hydrological conditions.