In this chapter, I have described the applied impedance inversion on the data from the Blake Outer Ridge and the subsequent AVO modeling analysis. The 2-D impedance inversion has shown that the BSR is characterized by a strong negative P-impedance contrast, as was expected from the observed decrease in interval velocity across this interface (Chapter 2). Furthermore, the BSR has a mostly positive S-impedance contrast. These impedance contrasts strongly suggest the presence of free gas beneath the BSR. The amplitudes along the BSR are distorted at several locations laterally along the BSR, probably due to thin layering underneath the BSR. The flat layer beneath the BSR has a positive P-impedance contrast and a very weak S-impedance contrast, indicating a transition from gas-saturated sediment to normal brine-saturated sediment. Because this flat reflector appears to be ``wedged'' against the portion of the BSR between 25 and 35 km lateral distance, the presence of a thin free gas layer underneath the BSR is implied. The subsequent AVO modeling confirmed the model of hydrate overlying free gas. A strong negative P-wave velocity contrast and a simultaneous increase in S-wave velocity is required to reproduce the observed increasing amplitude with increasing angle. This implies the presence of hydrate to increase the P-wave velocity in the hydrate-bearing sediments, but not drastically change the shear structure of the saturated sediment. Furthermore, a second AVO trend connected to the BSR, showing nearly constant amplitudes with angle, suggests the existence of some brine-saturated regions below the BSR. However, looking at the wavelet shape and the significant decrease in P-wave velocity, it night be more reasonable to assume that this trend was produced by thin bed tuning. Ostrander 1984 showed that thin bed tuning can affect amplitudes more than 30%. This would explain the distorted AVO trend.