The fjords of Chilean Patagonia are areas of relatively rapid Holocene sediment delivery from glacial, glacifluvial and fluvial systems. These systems are fed by substantial ice- and snow-melt on the flanks of the Andean mountains. Many fjords are infilled by tens of metres of fine-grained, acoustically laminated sediment leading to a relatively flat and undifferentiated appearance of the fjord floor except where mass-wasting and turbidity-current processes are operating (e.g. DaSilva et al. 1997; Araya-Vergara 1999, 2008; Boyd et al. 2008; Dowdeswell & Vásquez 2013). In some areas, pockmarks have been observed on the floor of fjords, whose origin has been linked to the escape of fluids from the underlying sediments.