Seismic attenuation in Faroe Islands basalts

F. Shaw, M.H. Worthington, R.S. White, M.S. Andersen, U.K. Petersen

Research output: Contribution to journalArticleResearchpeer-review

26 Citations (Scopus)

Abstract

We analysed vertical seismic profiling (VSP) data from two boreholes at Glyvursnes and Vestmanna on the island of Streymoy, Faroe Islands, to determine the magnitude and causes of seismic attenuation in sequences of basalt flows. The work is part of SeiFaBa, a major project integrating data from vertical and offset VSP, surface seismic surveys, core samples and wireline log data from the two boreholes. Values of effective seismic quality factor (Q) obtained at Glyvursnes and Vestmanna are sufficiently low to significantly degrade the quality of a surface reflection seismic image. This observation is consistent with results from other VSP experiments in the North Atlantic region. We demonstrate that the most likely cause of the low values of effective Q at Glyvursnes and Vestmanna is a combination of 1D scattering and intrinsic attenuation due to seismic wave-induced fluid flow within pores and micro-cracks. Tests involving 3D elastic wave numerical modelling with a hypothetical basalt model based on field observations, indicate that little scattering attenuation is caused by lateral variations in basalt structure.

Original languageEnglish
Pages (from-to)5-20
Number of pages16
JournalGeophysical Prospecting
Volume56
Issue number1
DOIs
Publication statusPublished - Jan 2008

Programme Area

  • Programme Area 3: Energy Resources

Fingerprint

Dive into the research topics of 'Seismic attenuation in Faroe Islands basalts'. Together they form a unique fingerprint.

Cite this