| Summary: | This report contains compiled results and synthesis for Task 4.2 within Work Package (WP) 4 of the EU funded IMAGE project. Within Task 4.2 several different Vertical Seismic Profiling (VSP) experiments including zero-offset VSP, far-offset VSP, multi-offset VSP, as well as source comparison and passive seismic monitoring were carried out in two boreholes within the Krafla high temperature geothermal field, NE-Iceland. Additional to the VSP experiments, new sonic log, televiewer and borehole cuttings analyses were carried out in one of the two boreholes to improve the geo-logical interpretation of the VSP data. The surveys were successfully completed and good data were obtained and processed for both wells. Integration of the results from the VSP experiments with the borehole analysis enabled successful linkage of the key lithological boundaries within the wells proving the ability of VSP to image key boundaries in a heterogeneous basalt dominated subsurface sequence. Utilizing the VSP results to look-ahead of the penetrated interval also revealed important reflectivity results below the well. This provides important verification of the technique. However, constraining the nature of the reflectivity in terms of fluid types, structure or mag-ma remains a challenge. In summary, Task 4.2 has produced a very large amount of high quality data and demonstrated the ability of the technique to image the complex subsurface of geothermally prospective volcanic edifices. The volume and quality of data has also created a highly valuable resource, which will enable numerous future investigations to look into the seismic structure of volcanic geothermal fields. FP7
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