Evidence for a Highly Dynamic West Antarctic Ice Sheet During the Pliocene

Major ice loss in the Amundsen Sea sector of West Antarctic Ice Sheet (WAIS) is hypothesized to have triggered sheet collapses during past warm periods such as those Pliocene. International Ocean Discovery Program (IODP) Expedition 379 recovered continuous late Miocene Holocene sediments from a sediment drift on continental rise, allowing assessment sedimentation processes response climate cycles and trends since Miocene. Via seismic correlation shelf, we interpret massive prograding sequences that extended outer shelf by 80 km Pliocene through frequent advances grounded ice. Buried grounding zone wedges indicate prolonged ice-sheet retreat, or even collapse, an mid-Pliocene period ∼4.2–3.2 Ma inferred records. These results WAIS was highly dynamic major retreat events may occurred along margin.