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Abstract. In late March 2011, landfast sea ice (hereafter, “fast ice”) formed in the northern Larsen B embayment and persisted continuously as multi-year fast ice until January 2022. In the 11 years of fast-ice presence, the northern Larsen B glaciers slowed significantly, thickened in their lower reaches, and developed extensive mélange areas, leading to the formation of ice tongues that extended up to 16 km from the 2011 ice fronts. In situ measurements of ice speed on adjacent ice shelf areas spanning 2011 to 2017 show that the fast ice provided significant resistive stress to ice flow. Fast-ice breakout began in late January 2022 and was closely followed by retreat and breakup of both the fast-ice mélange and the glacier ice tongues. We investigate the probable triggers for the loss of fast ice and document the initial upstream glacier responses. The fast-ice breakup is linked to the arrival of a strong ocean swell event (>1.5 m amplitude; wave period waves >5 s) originating from the northeast. Wave propagation to the ice front was facilitated by a 12-year low in sea ice concentration in the northwestern Weddell Sea, creating a near-ice-free corridor to the open ocean. Remote sensing data in the months following the fast-ice breakout reveals an initial ice flow speed increase (>2-fold), elevation loss (9 to 11 m), and rapid calving of floating and grounded ice for the three main embayment glaciers Crane (11 km), Hektoria (25 km), and Green (18 km).
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Clumped-isotope composition of molecular oxygen trapped in the Allan Hills S27 ice core
This file includes the clumped-isotope composition (18O18O) molecular oxygen (O2) that is in the trapped air from the S27 ice core collected in Allan Hills Blue Ice Area.
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- Award ID(s):
- 2002422
- PAR ID:
- 10578098
- Publisher / Repository:
- U.S. Antarctic Program (USAP) Data Center
- Date Published:
- Subject(s) / Keyword(s):
- Oxygen Last Interglacial Cryosphere Antarctica
- Format(s):
- Medium: X
- Location:
- Allan Hills; (East Bound Longitude:159.25; North Bound Latitude:-75.67; South Bound Latitude:-76.83; West Bound Longitude:159)
- Right(s):
- Creative Commons Attribution 4.0 International
- Institution:
- Rice University
- Sponsoring Org:
- National Science Foundation
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