Climate Change Data Portal
| DOI | 10.5194/tc-9-197-2015 |
| Glacier-surge mechanisms promoted by a hydro-thermodynamic feedback to summer melt | |
| Dunse T.; Schellenberger T.; Hagen J.O.; Kääb A.; Schuler T.V.; Reijmer C.H. | |
| 发表日期 | 2015 |
| ISSN | 19940416 |
| 卷号 | 9期号:1 |
| 英文摘要 | Mass loss from glaciers and ice sheets currently accounts for two-thirds of the observed global sea-level rise and has accelerated since the 1990s, coincident with strong atmospheric warming in the polar regions. Here we present continuous GPS measurements and satellite synthetic-aperture-radar-based velocity maps from Basin-3, the largest drainage basin of the Austfonna ice cap, Svalbard. Our observations demonstrate strong links between surface-melt and multiannual ice-flow acceleration. We identify a hydro-thermodynamic feedback that successively mobilizes stagnant ice regions, initially frozen to their bed, thereby facilitating fast basal motion over an expanding area. By autumn 2012, successive destabilization of the marine terminus escalated in a surge of Basin-3. The resulting iceberg discharge of 4.2±1.6 Gt a−1 over the period April 2012 to May 2013 triples the calving loss from the entire ice cap. With the seawater displacement by the terminus advance accounted for, the related sea-level rise contribution amounts to 7.2±2.6 Gt a−1. This rate matches the annual ice-mass loss from the entire Svalbard archipelago over the period 2003-2008, highlighting the importance of dynamic mass loss for glacier mass balance and sea-level rise. The active role of surface melt, i.e. external forcing, contrasts with previous views of glacier surges as purely internal dynamic instabilities. Given sustained climatic warming and rising significance of surface melt, we propose a potential impact of the hydro-thermodynamic feedback on the future stability of ice-sheet regions, namely at the presence of a cold-based marginal ice plug that restricts fast drainage of inland ice. The possibility of large-scale dynamic instabilities such as the partial disintegration of ice sheets is acknowledged but not quantified in global projections of sea-level rise. |
| 学科领域 | glacier mass balance; global warming; GPS; ice sheet; melting; polar region; sea level change; summer; thermodynamics; Arctic; Svalbard; Svalbard and Jan Mayen |
| 语种 | 英语 |
| scopus关键词 | glacier mass balance; global warming; GPS; ice sheet; melting; polar region; sea level change; summer; thermodynamics; Arctic; Svalbard; Svalbard and Jan Mayen |
| 来源期刊 | Cryosphere
 |
| 文献类型 | 期刊论文 |
| 条目标识符 | http://gcip.llas.ac.cn/handle/2XKMVOVA/119961 |
| 作者单位 | Department of Geosciences, University of Oslo, P.O. Box 1047, Blindern, Oslo, 0316, Norway; Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Princetonplein 5, Utrecht, 3584 CC, Netherlands |
| 推荐引用方式 GB/T 7714 | Dunse T.,Schellenberger T.,Hagen J.O.,et al. Glacier-surge mechanisms promoted by a hydro-thermodynamic feedback to summer melt[J],2015,9(1). |
| APA | Dunse T.,Schellenberger T.,Hagen J.O.,Kääb A.,Schuler T.V.,&Reijmer C.H..(2015).Glacier-surge mechanisms promoted by a hydro-thermodynamic feedback to summer melt.Cryosphere,9(1). |
| MLA | Dunse T.,et al."Glacier-surge mechanisms promoted by a hydro-thermodynamic feedback to summer melt".Cryosphere 9.1(2015). |
| 条目包含的文件 | 条目无相关文件。 | |||||
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