scholarly journals Volumetric variations of Glacier de Sarennes, French Alps, during the last two centuries

1997 ◽  
Vol 24 ◽  
pp. 361-366
Author(s):  
François Valla ◽  
Christian Piedallu
Keyword(s):  
Computer Program ◽  
Mass Balance ◽  
Cross Sections ◽  
Little Ice Age ◽  
Snow Accumulation ◽  
Ice Age ◽  
Ice Thickness ◽  
Reasonable Accuracy ◽  
French Alps ◽  
Ice Volume

Glacier de Sarennes, located in the heart of the French Alps, has been observed closely since 1906 and regularly measured (snow accumulation, ablation and mass balance) since 1948. Several publications have stemmed from this research, such as the 1906 and 1958 glaciological maps and the 1981 and 1991 photogrammetric analyses. In 1992, a field radar campaign determined the ice thickness and allowed the drawing of the bedrock map with reasonable accuracy. The Little Ice Age stage was reconstructed with the bedrock tracks, in 1995.The above-mentioned documents were digitized, and the computer program Arc-Info permitted the calculation of the successive volume stages occupied by the glacier from 1850 to 1991. Cross-sections and slope profiles illustrate the evolution of the thickness of Glacier de Sarennes during the last 150 years. All of these results, consistent with the variation of the mass balance observed or estimated, show the main conclusion: compared with today, the glacier was about four times more voluminous 90 years ago (i.e. it has lost three-quarters of its ice volume) and five times bigger one and a half centuries ago.

scholarly journals Volumetric variations of Glacier de Sarennes, French Alps, during the last two centuries

1997 ◽  
Vol 24 ◽  
pp. 361-366 ◽  
Author(s):  
François Valla ◽  
Christian Piedallu
Keyword(s):  
Computer Program ◽  
Mass Balance ◽  
Cross Sections ◽  
Little Ice Age ◽  
Snow Accumulation ◽  
Ice Age ◽  
Ice Thickness ◽  
Reasonable Accuracy ◽  
French Alps ◽  
Ice Volume

Glacier de Sarennes, located in the heart of the French Alps, has been observed closely since 1906 and regularly measured (snow accumulation, ablation and mass balance) since 1948. Several publications have stemmed from this research, such as the 1906 and 1958 glaciological maps and the 1981 and 1991 photogrammetric analyses. In 1992, a field radar campaign determined the ice thickness and allowed the drawing of the bedrock map with reasonable accuracy. The Little Ice Age stage was reconstructed with the bedrock tracks, in 1995. The above-mentioned documents were digitized, and the computer program Arc-Info permitted the calculation of the successive volume stages occupied by the glacier from 1850 to 1991. Cross-sections and slope profiles illustrate the evolution of the thickness of Glacier de Sarennes during the last 150 years. All of these results, consistent with the variation of the mass balance observed or estimated, show the main conclusion: compared with today, the glacier was about four times more voluminous 90 years ago (i.e. it has lost three-quarters of its ice volume) and five times bigger one and a half centuries ago.

scholarly journals Downscaled precipitation applied in modelling of mass balance and the evolution of southeast Vatnajökull, Iceland

2015 ◽  
Vol 61 (228) ◽  
pp. 799-813 ◽  
Author(s):  
Hrafnhildur Hannesdóttir ◽  
Guðfinna Ađalgeirsdóttir ◽  
Tómas Jóhannesson ◽  
Sverrir Guđmundsson ◽  
Philippe Crochet ◽  
...  
Keyword(s):  
Mass Balance ◽  
Little Ice Age ◽  
Ice Age ◽  
Balance Model ◽  
Ice Flow ◽  
Ice Volume ◽  
Precipitation Increase ◽  
Annual Balance ◽  
Measured Mass

AbstractSimulations of the post-Little Ice Age evolution of three outlet glaciers of southeast Vatnajökull, Iceland – Skálafellsjökull, Heinabergsjökull and Fláajökull – are presented. A coupled shallow-ice-approximation ice-flow and degree-day mass-balance model is applied that is calibrated with a 14 year record of in situ mass-balance measurements. The measured mass balance cannot be realistically represented by constant horizontal and vertical precipitation gradients. High-resolution (1 km) precipitation fields, derived from downscaled orographic atmospheric circulation models of precipitation, are required to capture the spatial variation of the winter mass balance. The observed ice volume around 1890 (15–30% larger than in 2000) can be simulated with 1°C lower temperatures and a 20% reduction in the annual precipitation, relative to the reference climate period, 1980–2000. The sensitivity of each glacier’s annual balance to a change in temperature is −1.51 to −0.97 m w.e. a−1 °C−1 and +0.16 to +0.65 m w.e. a−1 for a 10% increase in precipitation. A steady-state experiment applying a step increase in temperature of 2°C (3°C), and precipitation increase of 10%, results in a >50% (80–90%) decrease in ice volume.

scholarly journals Glacier dynamics at Helheim and Kangerdlugssuaq glaciers, southeast Greenland, since the Little Ice Age

2014 ◽  
Vol 8 (4) ◽  
pp. 1497-1507 ◽  
Author(s):  
S. A. Khan ◽  
K. K. Kjeldsen ◽  
K. H. Kjær ◽  
S. Bevan ◽  
A. Luckman ◽  
...  
Keyword(s):  
Mass Balance ◽  
Little Ice Age ◽  
Ice Age ◽  
Short Term ◽  
Velocity Change ◽  
Outlet Glacier ◽  
Episodic Events ◽  
Highly Sensitive ◽  
Decadal Scale ◽  
Speed Up

Abstract. Observations over the past decade show significant ice loss associated with the speed-up of glaciers in southeast Greenland from 2003, followed by a deceleration from 2006. These short-term, episodic, dynamic perturbations have a major impact on the mass balance on the decadal scale. To improve the projection of future sea level rise, a long-term data record that reveals the mass balance beyond such episodic events is required. Here, we extend the observational record of marginal thinning of Helheim and Kangerdlugssuaq glaciers from 10 to more than 80 years. We show that, although the frontal portion of Helheim Glacier thinned by more than 100 m between 2003 and 2006, it thickened by more than 50 m during the previous two decades. In contrast, Kangerdlugssuaq Glacier underwent minor thinning of 40–50 m from 1981 to 1998 and major thinning of more than 100 m after 2003. Extending the record back to the end of the Little Ice Age (prior to 1930) shows no thinning of Helheim Glacier from its maximum extent during the Little Ice Age to 1981, while Kangerdlugssuaq Glacier underwent substantial thinning of 230 to 265 m. Comparison of sub-surface water temperature anomalies and variations in air temperature to records of thickness and velocity change suggest that both glaciers are highly sensitive to short-term atmospheric and ocean forcing, and respond very quickly to small fluctuations. On century timescales, however, multiple external parameters (e.g. outlet glacier shape) may dominate the mass change. These findings suggest that special care must be taken in the projection of future dynamic ice loss.

scholarly journals Multidecadal Arctic sea ice thickness and volume derived from ice age

2020 ◽  
Vol 14 (4) ◽  
pp. 1325-1345 ◽  
Author(s):  
Yinghui Liu ◽  
Jeffrey R. Key ◽  
Xuanji Wang ◽  
Mark Tschudi
Keyword(s):  
Sea Ice ◽  
Global Climate ◽  
Arctic Sea Ice ◽  
Ice Age ◽  
The Arctic ◽  
Ice Thickness ◽  
Sea Ice Thickness ◽  
Ice Volume ◽  
Arctic Sea ◽  
Arctic Sea Ice Thickness

Abstract. Sea ice is a key component of the Arctic climate system, and has impacts on global climate. Ice concentration, thickness, and volume are among the most important Arctic sea ice parameters. This study presents a new record of Arctic sea ice thickness and volume from 1984 to 2018 based on an existing satellite-derived ice age product. The relationship between ice age and ice thickness is first established for every month based on collocated ice age and ice thickness from submarine sonar data (1984–2000) and ICESat (2003–2008) and an empirical ice growth model. Based on this relationship, ice thickness is derived for the entire time period from the weekly ice age product, and the Arctic monthly sea ice volume is then calculated. The ice-age-based thickness and volume show good agreement in terms of bias and root-mean-square error with submarine, ICESat, and CryoSat-2 ice thickness, as well as ICESat and CryoSat-2 ice volume, in February–March and October–November. More detailed comparisons with independent data from Envisat for 2003 to 2010 and CryoSat-2 from CPOM, AWI, and NASA GSFC (Goddard Space Flight Center) for 2011 to 2018 show low bias in ice-age-based thickness. The ratios of the ice volume uncertainties to the mean range from 21 % to 29 %. Analysis of the derived data shows that the ice-age-based sea ice volume exhibits a decreasing trend of −411 km3 yr−1 from 1984 to 2018, stronger than the trends from other datasets. Of the factors affecting the sea ice volume trends, changes in sea ice thickness contribute more than changes in sea ice area, with a contribution of at least 80 % from changes in sea ice thickness from November to May and nearly 50 % in August and September, while less than 30 % is from changes in sea ice area in all months.

scholarly journals Relation between recent glacier variations and climate in the Tien Shan mountains, central Asia

1992 ◽  
Vol 16 ◽  
pp. 11-16 ◽  
Author(s):  
Liu Chaohai ◽  
Han Tianding
Keyword(s):  
Mass Balance ◽  
Central Asia ◽  
Air Temperature ◽  
Little Ice Age ◽  
General Trend ◽  
Summer Temperature ◽  
Tien Shan ◽  
Ice Age ◽  
Climatic Fluctuations ◽  
Tien Shan Mountains

Since the Little Ice Age, most glaciers in the Tien Shan mountains have been retreating. Owing to an increase in precipitation in most parts of the mountains during the late 1950s to early 1970s, the percentage of receding glaciers and the speed of retreat have tended to decrease in the 1970s. However, the general trend of continuous glacier retreat remains unchanged, in part because the summer air temperature shows no tendency to decrease.In the Tien Shan mountains, as the degree of climatic continentality increases the mass balance becomes more dependent on summer temperature, and accumulation and ablation tend to be lower. Therefore, the responses of glaciers to climatic fluctuations in more continental areas are not synchronous with those in less continental areas, and the amplitude of the glacier variations becomes smaller.

Climatic Changes in the Qinghai-Xizang (Tibetan) Region of China during the Holocene

1987 ◽  
Vol 28 (1) ◽  
pp. 50-60 ◽  
Author(s):  
Wang Fu-Bao ◽  
C. Y. Fan
Keyword(s):  
Cross Sections ◽  
Little Ice Age ◽  
Climatic Changes ◽  
Northern Region ◽  
Ice Age ◽  
Southern Slope ◽  
The Holocene ◽  
Northeastern Part ◽  
Xizang Plateau ◽  
Sand And Gravel

AbstractClimatic changes in the Qinghai-Xizang Plateau of China were studied by analyzing the composition of peat and layers of sand and gravel distributed along the southern slopes of Nianqing-Tanggula and Gangdise Mountains, cross sections of deposits near a number of interior lakes in Xizang, past glacial variations on the southern slope of Nianqing-Tanggula Mountain, and landform changes south of the Yaluzangbu River. Such geologic evidence suggests a division of five climatic periods since the beginning of the Holocene: (1) The Wumadung interval, 10,000–7500 yr B.P., slightly cold and dry; (2) Qilongduo interval, 7500-3000 yr B.P., warm and moist; (3) the mid-Neoglacial period, 3000-1500 yr B.P., cold, except between 2500 and 200 yr B.P. when it was warmer; (4) the Dawelong interval, 1500-300 yr B.P., mild; and (5) the Little Ice Age, 300-0 yr B.P., cold. These changes progressed in a similar but not identical pattern as those in the northeastern part of China and in the northern region of Europe.

scholarly journals Mountain glaciers of southeast Siberia: current state and changes since the Little Ice Age

2014 ◽  
Vol 55 (66) ◽  
pp. 167-176 ◽  
Author(s):  
E.Yu. Osipov ◽  
O.P. Osipova
Keyword(s):  
Little Ice Age ◽  
Snow Accumulation ◽  
Ice Age ◽  
High Mountain ◽  
Late 20Th Century ◽  
Glacier Inventory ◽  
Mountain Glaciers ◽  
Current State ◽  
Field Investigations ◽  
Glacier Changes

AbstractContemporary glaciers of southeast Siberia are located on three high-mountain ridges (east Sayan, Baikalsky and Kodar). In this study, we present an updated glacier inventory based on high- to middle-resolution satellite imagery and field investigations. The inventory includes 51 glaciers with a total area of - 15 km2. Areas of individual glaciers vary from 0.06 to 1.33 km2, lengths from 130 to 2010 m and elevations from 1796 to 3490 m. The recent ice maximum extents (Little Ice Age) have been delineated from terminal moraines. On average, debris-free surface area shrunk by 59% between 1850 and 2006/11 (0.37% a–1), by 44% between 1850 and 2001/02 (0.29% a–1) and by 27% between 2001/02 and 2006/11 (3.39% a–1). The Kodar glaciers have experienced the largest area shrinkage, while the area loss on Baikalsky ridge was more moderate. Glacier changes are mainly related to regional summer temperature increase (by 1.7-2.6C from 1970 to 2010). There are some differences in glacier response due to different spatial patterns of snow accumulation, local topography (e.g. glacier elevation, slope) and geological activity. The studied glaciers (especially of Kodar ridge) are the most sensitive in Siberia to climate change since the late 20th century.

scholarly journals Estimating South Cascade Glacier (Washington, U.S.A.) mass balance from a distant radiosonde and comparison with Blue Glacier

2001 ◽  
Vol 47 (159) ◽  
pp. 579-588 ◽  
Author(s):  
L. A. Rasmussen ◽  
H. Conway
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Little Ice Age ◽  
Ice Age ◽  
The Past ◽  
Recent Warming ◽  
Flux Model ◽  
Present Area

AbstractA simple flux model using twice-daily measurements of wind, humidity and temperature from standard upper-air levels in a distant radiosonde estimated winter balance of South Cascade Glacier, Washington, U.S.A., over 1959–98 with error 0.24 m w.e. Correlation between net and winter balance is strong; the model estimates net balance with error 0.53 m w.e. Over the past 40 years, average net balance of South Cascade Glacier has been strongly negative (−0.46 m w.e.), and it has been shrinking steadily. In comparison, 200 km west-southwest at Blue Glacier, the average balance has been less negative (−0.13 m w.e); that glacier has undergone little change over the 40 years. Balance histories of the two glaciers are positively correlated (r = +0.54), and South Cascade has been more out of balance than Blue, presumably because it is still adjusting to climate change since the Little Ice Age. Recent warming and drying has made the net balance of both glaciers strongly negative since 1976 (−0.84 m w.e. at South Cascade, −0.56 m w.e. at Blue). If South Cascade Glacier were in balance with the 1986–98 climate, it would be about one-quarter of its present area.

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