The life and death of a subglacial lake in West Antarctica

Over the past 50 years, the discovery and initial investigation of subglacial lakes in Antarctica have highlighted the paleoglaciological information that may be recorded in sediments at their beds. In December 2018, we accessed Mercer Subglacial Lake, West Antarctica, and recovered the first in situ subglacial lake-sediment record-120 mm of finely laminated mud. We combined geophysical observations, image analysis, and quantitative stratigraphy techniques to estimate long-term mean lake sedimentation rates (SRs) between 0.49 +/- 0.12 mm a-1 and 2.3 +/- 0.2 mm a-1, with a most likely SR of 0.68 +/- 0.08 mm a-1. These estimates suggest that this lake formed between 53 and 260 a before core recovery (BCR), with a most likely age of 180 +/- 20 a BCR-coincident with the stagnation of the nearby Kamb Ice Stream. Our work demonstrates that interconnected subglacial lake systems are fundamentally linked to larger-scale ice dynamics and highlights that subglacial sediment archives contain powerful, century-scale records of ice history and provide a modern process -based analogue for interpreting paleo-subglacial lake facies.

Automated summary

Over the past 50 years, the discovery and investigation of subglacial lakes in Antarctica have provided valuable information about paleoglaciology. In December 2018, the first in situ subglacial lake-sediment record was recovered from Mercer Subglacial Lake in West Antarctica. Through various techniques, we estimated the long-term mean lake sedimentation rates, suggesting a most likely age of 180 +/- 20 years before core recovery (BCR). This research demonstrates the significance of interconnected subglacial lake systems in understanding ice dynamics and highlights the potential of subglacial sediment archives as records of ice history.