Geodetic Mass Balance of Svalbard glaciers : 1936 - 2004
Glaciers and ice masses are very important components of the earth system both in terms of global water storage and as climate indicators. The amount of water tied up in glaciers and ice caps is equivalent to about 69 meters of sea-level (Church and others, 2001). Recent predictions from global clim...
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| Format: | Master Thesis |
| Language: | English |
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2007
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| Online Access: | http://hdl.handle.net/10852/12415 http://urn.nb.no/URN:NBN:no-14308 |
| Summary: | Glaciers and ice masses are very important components of the earth system both in terms of global water storage and as climate indicators. The amount of water tied up in glaciers and ice caps is equivalent to about 69 meters of sea-level (Church and others, 2001). Recent predictions from global climate models indicate the arctic will experience enhanced changes as compared to the lower latitudes linked to the rise of greenhouse gases in the next 100 years (ACIA report, 2005). Svalbard glaciers and ice masses may therefore experience a rapid response to a change in climate (Hagen and others, 2003a). It is thus beneficial to document both present and the long term past glacier fluctuations to increase the comprehension of climatic changes. Svalbard is a high arctic archipelago, located in a climatically sensitive area at the northern extremity of the warm North Atlantic ocean current. Approximately 36000 km2 is covered by glaciers consisting of ice caps, tidewater, outlet, and smaller cirque and piedmont glaciers (Hagen and others, 1993). In this study, a 54 year geodetic balance of Svalbard glaciers is derived by comparing the oldest topographic map series of Svalbard (1936/38) to modern digital elevation models (DEM) from 1990. The errors of the older maps are assessed where precision is limited, but accuracy is sufficient for glacier studies. Elevation changes are analyzed for 7 regions in Svalbard (~5000 km2), where significant thinning was found at glacier fronts, and elevation increases in the upper parts of the accumulation areas. All regions experience volume losses and negative geodetic balances, although regional variability exists relating to both climate and topography. Many surges are apparent within the elevation change maps. Estimated volume change for the regions is -1.59±0.07 km3a-1 (ice eq.) for a geodetic annual balance of -0.30 m a-1 (w. eq.), and the glaciated area has decreased by 16% in the 54 year time interval. For recent balance estimations, differential GPS (2004) and laser altimetry ... |
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