A computer system for generating and displaying attribute renderings from a seismic data volume, comprising: - a first computer readable memory wherein a 3D seismic data volume is stored, said 3D seismic data volume comprising two lateral dimensions and one depth dimension; - a second computer readable memory wherein a plurality of horizons is stored, of which plurality of horizons each horizon is a surface that connects selected seismic events in the 3D seismic data volume that have been associated with a single geological feature; - a first display on which the 3D seismic data volume is shown, together with an interactive cursor ; and - a user-input device configured to control the interactive cursor , by means of which a user can select any point within the 3D seismic data volume on or between said plurality of horizons; - a first processing unit ; - a second processing unit connected to the first processing unit ; and - a second display ; characterized in that : - the first processing unit is programmed with computer executable instructions to dynamically calculate a horizon-based stratal slice through the 3D seismic data volume based on at least one of the horizons of said plurality of horizons and which includes a user-selected point within the 3D seismic data volume on or between the plurality of horizons as indicated by the interactive cursor in response to interaction of the user with the user-input device ; - the second processing unit is programmed with computer executable instructions to dynamically generate a selected attribute rendering from seismic data that is contained within a slab that contains the horizon-based stratal slice ; and - the second display shows the selected attribute rendering. - a first computer readable memory wherein a 3D seismic data volume is stored, said 3D seismic data volume comprising two lateral dimensions and one depth dimension; - a second computer readable memory wherein a plurality of horizons is stored, of which plurality of horizons each horizon is a surface that connects selected seismic events in the 3D seismic data volume that have been associated with a single geological feature; - a first display on which the 3D seismic data volume is shown, together with an interactive cursor ; and - a user-input device configured to control the interactive cursor , by means of which a user can select any point within the 3D seismic data volume on or between said plurality of horizons; - a first processing unit ; - a second processing unit connected to the first processing unit ; and - a second display ; - the first processing unit is programmed with computer executable instructions to dynamically calculate a horizon-based stratal slice through the 3D seismic data volume based on at least one of the horizons of said plurality of horizons and which includes a user-selected point within the 3D seismic data volume on or between the plurality of horizons as indicated by the interactive cursor in response to interaction of the user with the user-input device ; - the second processing unit is programmed with computer executable instructions to dynamically generate a selected attribute rendering from seismic data that is contained within a slab that contains the horizon-based stratal slice ; and - the second display shows the selected attribute rendering. <EOS>