| 1. |
- Beedle, M., et al.
(författare)
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Improving estimation of glacier volume change: a GLIMS case study of Bering Glacier System, Alaska.
- 2008
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Ingår i: The Cryosphere. - 1994-0416. ; 2:1, s. 33-51
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Tidskriftsartikel (refereegranskat)abstract
- The Global Land Ice Measurements from Space (GLIMS) project has developed tools and methods that can be employed by analysts to create accurate glacier outlines. To illustrate the importance of accurate glacier outlines and the effectiveness of GLIMS standards we conducted a case study on Bering Glacier System (BGS), Alaska. BGS is a complex glacier system aggregated from multiple drainage basins, numerous tributaries, and many accumulation areas. Published measurements of BGS surface area vary from 1740 to 6200 km2, depending on how the boundaries of this system have been defined. Utilizing GLIMS tools and standards we have completed a new outline (3630 km2) and analysis of the area-altitude distribution (hypsometry) of BGS using Landsat images from 2000 and 2001 and a US Geological Survey 15-min digital elevation model. We compared this new hypsometry with three different hypsometries to illustrate the errors that result from the widely varying estimates of BGS extent. The use of different BGS hypsometries results in highly variable measures of volume change and net balance (bn). Applying a simple hypsometry-dependent mass-balance model to different hypsometries results in a bn rate range of −1.0 to −3.1 m a−1 water equivalent (W.E.), a volume change range of −3.8 to −6.7 km3 a−1 W.E., and a near doubling in contributions to sea level equivalent, 0.011 mm a−1 to 0.019 mm a−1. Current inaccuracies in glacier outlines hinder our ability to correctly quantify glacier change. Understanding of glacier extents can become comprehensive and accurate. Such accuracy is possible with the increasing volume of satellite imagery of glacierized regions, recent advances in tools and standards, and dedication to this important task.
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| 2. |
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| 3. |
- Dyurgerov, M., et al.
(författare)
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Integrated assessment of changes in freshwater inflow to the Arctic Ocean
- 2010
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 115:D12116
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Tidskriftsartikel (refereegranskat)abstract
- We present an integrated and updated quantitative estimation of the river discharge and the meltwater flux and mass contributions from glaciers to the Arctic Ocean and to sea level rise. The average meltwater fluxes from mountain glaciers and ice caps and the Greenland ice sheet have increased markedly, by 56 km3/yr water equivalent (w.e.) and 160 km3/yr w.e., respectively, from the period 1961–1992 to the period 1993–2006, reaching in total 700–800 km3/yr w.e. in 2000–2006. Terrestrial runoff is on the order of 2.4 × 103 km3/yr and remains significantly larger than the glacier meltwater flux. The terrestrial runoff increase from 1961–1992 to 1993–2006 is 87 km3/yr, which is small in relative terms, but in absolute terms it is of the same order of magnitude as the meltwater increase from glaciers. The total contribution to sea level rise from glaciers draining to the Arctic Ocean has increased from 0.27 mm/yr (1961–1992) to about 0.64 mm/yr (1993–2006). In some years of the 1993–2006 period, the glacier contribution to sea level rise reached almost 1 mm/yr.
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| 4. |
- Meier, MF, et al.
(författare)
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Glaciers dominate eustatic sea-level rise in the 21st Century
- 2007
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 317:5841, s. 1064-1067
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Tidskriftsartikel (refereegranskat)abstract
- Ice loss to the sea currently accounts for virtually all of the sea-level rise that is not attributable to ocean warming, and about 60% of the ice loss is from glaciers and ice caps rather than from the two ice sheets. The contribution of these smaller glaciers has accelerated over the past decade, in part due to marked thinning and retreat of marine-terminating glaciers associated with a dynamic instability that is generally not considered in mass-balance and climate modeling. This acceleration of glacier melt may cause 0.1 to 0.25 meter of additional sea-level rise by 2100.
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| 5. |
- Oerlemans, J., et al.
(författare)
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Reconstructing the glacier contribution to sea-level rise back to 1850
- 2007
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Ingår i: CRYOSPHERE. - 1994-0416. ; 1:1, s. 59-65
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Tidskriftsartikel (refereegranskat)abstract
- We present a method to estimate the glacier contribution to sea-level rise from glacier length records. These records form the only direct evidence of glacier changes prior to 1946, when the first continuous mass-balance observations began. A globally representative length signal is calculated from 197 length records from all continents by normalisation and averaging of 14 different regions. Next, the resulting signal is calibrated with mass-balance observations for the period 1961-2000. We find that the glacier contribution to sea level rise was 5.5 +/- 1.0 cm during the period 1850-2000 and 4.5 +/- 0.7 cm during the period 1900-2000.
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