A Study of Seismic Attenuation in Basalt Using VSP Data from a Faroe Islands Borehole

P015 A STUDY OF SEISMIC ATTENUATION IN BASALT USING VSP DATA FROM A FAROE ISLANDS BOREHOLE. Summary 1 We describe an investigation of the magnitude and mechanisms of seismic attenuation in basaltic sequences. Using near-zero-offset vertical seismic profile (VSP) data collected from the Faroe Islands measurements of effective seismic attenuation have been obtained using the spectral ratio method. A change of Q occurs between the Faroes Upper and Middle basalt series but with Q values that are similar to those of other investigations of basalt in the North Atlantic region. The upgoing wave derived from the VSP data is approximately