Warm Seawater Under Thwaites Could Bring Faster Sea Level Rise

Proceedings of the National Academy of Sciences, 20 May 2024

Seawater pulses from tides moving beneath the vulnerable Thwaites Glacier has created a 6-kilometer zone where warm water repeatedly flows underneath the ice, speeding up melting. This tidal pulsing has increased the glacier’s instability, and therefore the rate at which it contributes to global sea-level rise. Past studies identified the same behavior beneath the rapidly receding Petermann Glacier in Greenland; however, Petermann is only 15 km wide where it touches the ocean, compared to 120 km for Thwaites. This continuous flushing of warm ocean water underneath the ice extends much further inland than previously thought, and could be the missing link between the rapid observed ice loss, versus slower changes predicted by most ice sheet models. Such findings raise concerns about similar melt and resulting sea-level rise underestimates from other major outlet glaciers in Greenland and Antarctica.

Full paper: https://www.pnas.org/doi/full/10.1073/pnas.2404766121
Plain-language briefing: https://www.washingtonpost.com/climate-environment/2024/05/20/thwaites-glacier-melt-sea-level-rise/