Data for: Seawater intrusions in the observed grounding zone of Petermann Glacier causes extensive retreat

Understanding grounding line dynamics is critical for projecting glacier evolution and sea level rise. Recent observations from satellite radar interferometry reveal rapid grounding line migration forced by oceanic tides that are several kilometers larger than predicted by hydrostatic equilibrium alone, indicating that the transition from grounded to floating ice is more complex than previously thought. Recent studies suggest that seawater intrusions beneath grounded ice may play a role in glacier dynamics. Here, we investigate their impact on the evolution of Petermann Glacier, Greenland, using an ice sheet model. We compare the model results with observed changes in grounding line position, velocity, and ice elevation between 2010 and 2022. If we exclude seawater intrusions, the model requires anomalously high melt rates to replicate the retreat. Conversely, we match the observed retreat with 3-km-long seawater intrusions with a maximum ice shelf melt rate of 50~m/yr, consistent with ..., , , # Data for: Seawater intrusions in the observed grounding zone of Petermann Glacier causes extensive retreat

[https://doi.org/10.5061/dryad.9kd51c5qv](https://doi.org/10.5061/dryad.9kd51c5qv)

#### Author Information:

A. Principal Investigator Contact Information

Name: Shivani Ehrenfeucht;
Institution: University of California- Irvine;
Email: [[e-mail]](mailto:[e-mail])

B. Co-Author

Name: Eric Rignot;
Institution: University of California- Irvine;
Email: [[e-mail]](mailto:[e-mail])

C. Co-Author

Name: Mathieu Morlighem;
Institution: Dartmouth College;
Email: [[e-mail]](mailto:[e-mail])

#### Project Description:

Recent observations suggest that seawater rushes between the glacier base and the bedrock at high tide. The presence of ocean water at this boundary, referred to as seawater intrusion, has the potential to increase grounded ice melt. We test this hypothesis on Petermann Glacier, Greenland, using ...