We are very grateful to all above named participants. We thank Orkustofnun for excellent preparation and support of the logging campaigns. We like to thank the owners of the boreholes for their permission to work in the wells. We are very grateful to GeoSys company and the Geophysical Institute of Karlsruhe University for lending us a BHTV and additional equipment for the logging campaign in June 1998. We also thank the GFZ logging team very much. We are also indebted to F. Lorenzo Martín for assisting in the graphics and checking the text.