[FIRST PARAGRAPH] Ice streams are narrow fast-flowing zones within ice sheets, and in the case of Antarctica are responsible for draining up to 90% of the mass from the ice sheet. It has been shown that Quaternary ice sheets were profoundly, and arguably catastrophically, influenced by the operation of transitory ice streaming. The palaeo-ice stream that operated through Hudson Strait for example, destabilized the Laurentide Ice Sheet, changed its configuration and thickness, and the resultant iceberg melt cooled North Atlantic waters enough to alter ocean circulation and produce ~4°C flips in climate on abrupt time scales.