Image-D4.04: Final Report On Estimating Crustal Stress And Fracture Permeability

• Main Author: Heidbach, Oliver
• Format: Text
• Language: English
• Published: Zenodo 2017
• Subjects: geothermal energy; exploration; crustal stress; fracture permeability; geophysics; Iceland; Krafla
• Online Access: https://dx.doi.org/10.5281/zenodo.1256393; https://zenodo.org/record/1256393

This document summarizes the results of Task 4.4 that consists of the analysis of crustal stress data and data of the fracture permeability for Iceland. This is the final report of the status of data analysis and compilation. In addition to an increase in data records the report provides the integration of the findings presented in the preliminary report (IMAGE-D4.08) into a wider context. The stress data analysis of image log data from 51 boreholes in Iceland has been performed and is summarized in the preliminary report. For the final report the number of data records was further increased by including also data from earthquake focal mechanism and geological indicators. The final result is a stress database for Iceland with ten times more data records on the stress state than previously available (increase from 38 to 485 data records) and enabled us to analyse in detail the stress pattern of whole Iceland and to identify distinct stress provinces. The results are published in the peer-reviewed journal Tectonophysics (Ziegler et al., 2016a; Appendix A) and in a new comprehensive stress map of Iceland (Ziegler et al., 2016b; Appendix B). The study of fracture permeability’s has been performed through original field studies carried out in Geitafell (Iceland) the field area chosen as analogue of the presently active geothermal systems of Krafla presented in the preliminary report and in the Skagafjör›ur area. The obtained results are in agreement with data from literature and direct measurements in boreholes. Furthermore the data is an extension to the stress database. : FP7