A refreshing 3D view of an ancient sediment collapse and slope failure

The combined analysis of high-resolution 2D seismics and an industrial 3D seismic data volume from the western Porcupine Basin, offshore SW Ireland, revealed an unusual picture of a buried sediment collapse and slope failure. A proportionally thin (=750 km2) slab of consolidated sediments started to slide downslope, in the meantime breaking into hundreds of vertically undisturbed blocks, up to 500m in diameter. The most probably overpressured underlying horizon seems to have liquefied and acted as a slide plane until the excess pore pressure had dissipated. Then – still very early in the slide development – the process stopped, freezing the failure at its initial stage