d18O time series evidence of ocean-driven basal melt in Pine Island Bay, Antarctica

It is hypothesized that much of the mass loss from Western Antarctica is driven by basal melt along grounding lines due to warmer deep waters - this subsurface melt cannot be directly detected by satellites. Here, we present a time series from 2009-2019 of direct meltwater measurements using d18O and Salinity data. 2009 was thought to be an anomalously high melt year, and there is evidence of a pronounced increase in the presence of meltwater in 2019. Comparing two stations, 10 years apart, nearby the Pine Island glacier, there is evidence of 60% greater meltwater presence in 2019 vs 2009 - this increase is made more striking by the fact that the station in 2019 was nearly 100km further from the Pine Island Glacier than the station in 2009.