Drilling into fractured reservoirs demands an understanding of the fracture distribution and the associated stress eld to reduce the risk of failure. The seismic method provides the key to this risk reduction. Here, assuming fracture-related azimuthal anisotropy, we present a generalization of existing formulae for fracture detection. This uses the three P-wave attributes, amplitude, NMO velocity and traveltime, derived from marine seismic data shot along orthogonal directions. The attribute eld formed between two orthogonal survey lines displays a cos 2 variation with the line azimuth measured relative to the fracture strike. Thus, two pairs of orthogonal lines may be used to quantify the fracture strike b y cross-plotting these attributes. The technique is applied to data from the North Sea and veri ed using full-wave modelling.