Accelerated Antarctic ice loss through ocean forced changes in subglacial hydrology

Abstract Recent changes in Southern Ocean temperature have been linked with catchment-wide Antarctic ice acceleration and loss. The ice sheet models producing future sea level projections, however, rely on controversial mechanisms to match this rapid response, possibly due to the omission of feedbacks between subglacial water pressure and ice velocity. While modern remote sensing data tie increased subglacial water pressure to ice acceleration, there exists no record of subglacial hydrology long enough to evaluate this feedback on timescales relevant to climate and sea level change. Here we present a ten-thousand-year record of subglacial water dynamics and chemistry from ~110 ka East Antarctic calcite and sediment-bearing subglacial precipitates. Time series of sediment frequency and grain size indicate that changes in subglacial water dynamics correlate with Southern Ocean temperature. Similarly, shifts in calcite composition record climate-driven changes in subglacial water provenance. The synchronized changes in subglacial hydrology with climate support subglacial water drainage systems as having a key role in transferring the climate forcing acting on ice sheet margins, deep into ice sheet interior. The demonstrated coupling between subglacial water and climate clarifies the current rapid ice response to climate change in Antarctica, and underscores a need and means to heighten the sensitivity of ice sheet models.