Seismic imaging through basalt flows on the Faroes Shelf

• Main Authors: White, R. S., Spitzer, R., Christie, P. A. F., Roberts, A. W., Lunnon, Z., Maresh, J., Group, iSimm Working
• Other Authors: Ziska, H., Varming, T., Blotch, D.
• Format: Book Part
• Language: English
• Published: Føroya Fróðskaparfelag 2005
• Subjects: 02 - Geodynamics; Geophysics and Tectonics; Faroe Shelf; Faroes; Iceland; North Atlantic
• Online Access: http://eprints.esc.cam.ac.uk/1557/; http://eprints.esc.cam.ac.uk/1557/1/White_R.S._et_al_Faroe_Islands_Exploration_Conf,_Supp_43_%282005%29.pdf

Massive magmatism occurred on the North Atlantic margins when the continents broke apart in the presence of the Iceland mantle plume. The extrusive basalts on the Faroe shelf create a considerable problem for seismic imaging by causing extensive scattering from the multiple lava flows and by attenuating the higher frequencies in the seismic signal. We have made considerable advances in imaging through the basalts and into the underlying sediments and basement by focussing on the generation and recording of low-frequency energy centred on 10 HZ and by making use of the additional information available from long off-set data. We show how such low frequency seismic signals can be generated and recorded and how long off-set data can be acquired using currently available technology. We outline the processing and imaging strategies we have developed and show results which illustrate these techniques from two recent seismic experiments (FLARE and iSSIM), shot across the Faroes Shelf and adjacent continental margin. Combination of normal incidence and wide-angle seismic data, together with the use of sources and receivers tuned to the low frequencies required for intra- and sub-basalt penetration enable us to see structure both within and below the basalts.