Final deglaciation of the Scandinavian Ice Sheet and implications for the Holocene global sea-level budget
The last deglaciation of the Scandinavian Ice Sheet (SIS) from ∼21,000 to 13,000 yr ago is well-constrained by several hundred ¹⁰Be and ¹⁴C ages. The subsequent retreat history, however, is established primarily from minimum-limiting ¹⁴C ages and incomplete Baltic-Sea varve records, leaving a substa...
| Main Authors: | , , , , , , , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English unknown |
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Elsevier
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| Subjects: | |
| Online Access: | https://ir.library.oregonstate.edu/concern/articles/3t945s73c |
| Summary: | The last deglaciation of the Scandinavian Ice Sheet (SIS) from ∼21,000 to 13,000 yr ago is well-constrained by several hundred ¹⁰Be and ¹⁴C ages. The subsequent retreat history, however, is established primarily from minimum-limiting ¹⁴C ages and incomplete Baltic-Sea varve records, leaving a substantial fraction of final SIS retreat history poorly constrained. Here we develop a high-resolution chronology for the final deglaciation of the SIS based on 79 ¹⁰Be cosmogenic exposure dates sampled along three transects spanning southern to northern Sweden and Finland. Combining this new chronology with existing ¹⁰Be ages on deglaciation since the Last Glacial Maximum shows that rates of SIS margin retreat were strongly influenced by deglacial millennial-scale climate variability and its effect on surface mass balance, with regional modulation of retreat associated with dynamical controls. Ice-volume estimates constrained by our new chronology suggest that the SIS contributed ∼8 m sea-level equivalent to global sea-level rise between ∼14.5 ka and 10 ka. Final deglaciation was largely complete by ∼10.5 ka, with highest rates of sea-level rise occurring during the Bølling–Allerød, a 50% decrease during the Younger Dryas, and a rapid increase during the early Holocene. Combining our SIS volume estimates with estimated contributions from other remaining Northern Hemisphere ice sheets suggests that the Antarctic Ice Sheet (AIS) contributed 14.4±5.9 m to global sea-level rise since ∼13 ka. This new constraint supports those studies that indicate that an ice volume of 15 m or more of equivalent sea-level rise was lost from the AIS during the last deglaciation. Keywords: sea level, Holocene, ice sheet |
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