Figure F6. Panels above, left show north-south–trending vertical slices from the 3-D seismic data volume that extend from the western flank to the summit (see map above, right). Sites drilled during Leg 204 are shown. From left, lower panels are maps of the depth of Horizon A beneath the BSR and the seafloor and of the amplitude of Horizon A. These maps show that changes in the amplitude of Horizon A are correlated with the depth of Horizon A beneath the sea surface (pressure) rather than depth beneath the seafloor (primarily temperature), suggesting that the onset of very strong reflectivity may indicate the onset of gas exsolution within Horizon A. Other labels as in Figure F5. The length of the lines representing sites indicates maximum depth of penetration at that site, and horizontal ticks are located 75 m apart.