In: The Cryosphere, 2020, vol. 14, no. 11, p. 3785-3810
Perennial snow, or firn, covers 80 % of the Greenland ice sheet and has the capacity to retain surface meltwater, influencing the ice sheet mass balance and contribution to sea-level rise. Multilayer firn models are traditionally used to simulate firn processes and estimate meltwater retention. We present, intercompare and evaluate outputs from nine firn models at four sites that represent...
|
In: Nature, 2019, vol. 568, no. 7752, p. 382–386
|
In: Cold Regions Science and Technology, 2019, vol. 165, p. 102788
The warming climate is changing the surface dynamics of the Greenland Ice Sheet, including the balance between snowfall and melt. Increasing surface melt impacts the structure of the relatively porous near-surface layer known as firn. Camp Century, a base abandoned in 1967, now comprises a subsurface debris field within the firn in Northwest Greenland. We collected 80 km of 100 or 250 MHz...
|
In: Science Advances, 2018, vol. 4, no. 11, p. eaar8173
We report the discovery of a large impact crater beneath Hiawatha Glacier in northwest Greenland. From airborne radar surveys, we identify a 31-kilometer-wide, circular bedrock depression beneath up to a kilometer of ice. This depression has an elevated rim that cross-cuts tributary subglacial channels and a subdued central uplift that appears to be actively eroding. From ground...
|
In: The Cryosphere, 2014, vol. 8, no. 5, p. 1741–1755
Glacier length is an important measure of glacier geometry. Nevertheless, global glacier inventories are mostly lacking length data. Only recently semi-automated approaches to measure glacier length have been developed and applied regionally. Here we present a first global assessment of glacier length using an automated method that relies on glacier surface slope, distance to the glacier margins...
|
In: Front. Earth Sci. - Cryospheric Sciences, 2016, p. 18
A re-analysis is presented here of a 10 year mass balance series at Findelengletscher, a temperate mountain glacier in Switzerland. Calculating glacier-wide mass balance from the set of glaciological point balance observations using conventional approaches, such as the profile or contour method, resulted in significant deviations from the reference value given by the geodetic mass...
|
In: Annals of Glaciology, 2016, vol. 57, no. 71, p. 119–130
Surface digital elevation models (DEMs) and slope-related estimates of glacier thickness enable modelling of glacier-bed topographies over large ice-covered areas. Due to the erosive power of glaciers, such bed topographies can contain numerous overdeepenings, which when exposed following glacier retreat may fill with water and form new lakes. In this study, the bed overdeepenings for ~28 000...
|
In: The Cryosphere, 2018, vol. 12, no. 8, p. 2515–2544
At the Last Glacial Maximum (LGM), the Rhine glacier in the Swiss Alps covered an area of about 16000km2. As part of an integrative study about the safety of repositories for radioactive waste under ice age conditions in Switzerland, we modeled the Rhine glacier using a thermodynamically coupled three-dimensional, transient Stokes flow and heat transport model down to a horizontal resolution...
|
In: Geomorphology, 2020, vol. 355, p. 107068
Aosta Valley (Western Alps, Italy) is the region with the largest glacierized area of Italy. Like other high mountain regions, it has shown a significant glacier retreat starting from the end of the ‘Little Ice Age’ that is expected to continue in the future. As a direct consequence of glacier shrinkage, glacier-bed overdeepenings become exposed, offering suitable geomorphological ...
|
In: Nature, 2019, vol. 573, no. 7774, p. 403–407
In recent decades, meltwater runoff has accelerated to become the dominant mechanism for mass loss in the Greenland ice sheet1,2,3. In Greenland’s high- elevation interior, porous snow and firn accumulate; these can absorb surface meltwater and inhibit runoff4, but this buffering effect is limited if enough water refreezes near the surface to restrict percolation5,6. However, the influence...
|
