The Ronne Ice Shelf survived the last interglacial.

Area of Science:

• Paleoclimatology
• Glaciology
• Sea-level research

Background:

• The West Antarctic Ice Sheet's (WAIS) contribution to past sea-level rise is uncertain.
• Last Interglacial (LIG) sea levels were higher, implying significant Antarctic ice loss.
• Warmer LIG conditions in Antarctica and the Southern Ocean resemble future climate projections.

Purpose of the Study:

• To reconstruct the LIG extent of the WAIS and its ice shelves.
• To provide observational constraints on LIG ice sheet behavior.
• To reassess LIG sea-level contributions and future sea-level rise projections.

Main Methods:

• Analysis of sea salt data from an ice core at Skytrain Ice Rise.
• Interpretation of water isotope data from the same ice core.
• Comparison of findings with existing paleoclimate models and data.

Main Results:

• The Ronne Ice Shelf was largely present throughout most of the LIG.
• WAIS retreat occurred, but likely not to the extent of complete ice shelf loss.
• Observed LIG WAIS extent is inconsistent with models predicting dramatic ice loss.

Conclusions:

• The LIG WAIS was more stable than some models suggest.
• Reevaluation of LIG sea-level budget components is necessary.
• The observational basis for extreme future sea-level rise projections is weakened.