scholarly journals Glaciological response to distal tephra fallout from the 1947 eruption of Hekla, south Iceland

2003 ◽  
Vol 49 (166) ◽  
pp. 420-428 ◽  
Author(s):  
Martin P. Kirkbride ◽  
Andrew J. Dugmore
Keyword(s):  
Mass Balance ◽  
Ablation Rate ◽  
Spatial Variations ◽  
Glacier Surface ◽  
Western Margin ◽  
Eastern Margin ◽  
Maritime Climate ◽  
Tephra Fallout

AbstractGlacier responses to tephra deposition are shown to be highly variable where wind-transported eruption plumes produce narrow distal fallout zones with steep lateral thickness gradients. Significant but short-lived advances of faster-flowing glaciers can be triggered by deposition from modest eruptions. The 1947 eruption of Hekla, south Iceland, covered nearby glaciers with variable thicknesses of tephra, causing dramatic spatial variations in ablation rate. Relative snow ablation increased by an estimated >80% at the eastern margin of Eyjafjallajökull, but decreased by >54% at the western margin. Relative ice ablation increased by only 4% in the east but decreased by >75% at the western margin, only 15 km distant. The effect on mass balance therefore depends on tephra distribution as well as on the nature of the glacier surface. On Gígjökull, retardation of ablationwas greatest at the terminus, associated with an anomalous advance of ≥328 m between 1947 and 1954. Other glaciers in the fallout zone show either no recognizable response, or accelerated retreat. Advances will be short-lived due to the rapid redistribution of supraglacial tephra in a maritime climate, and the potential for discriminating between volcanically and climatically forced advances in the glacio-geomorphological record is low. The long-term glaciological effect of volcanism is to create thin, low-albedo covers after reworking, which make conditions less favourable for glaciation.

scholarly journals Meteorological controls on glacier mass balance: empirical relations suggested by measurements on glacier de Sarennes, France

1997 ◽  
Vol 43 (143) ◽  
pp. 131-137 ◽  
Author(s):  
C. Vincent ◽  
M. Vallon
Keyword(s):  
Mass Balance ◽  
Time Scale ◽  
Meteorological Data ◽  
Empirical Relation ◽  
Glacier Mass Balance ◽  
Glacier Surface ◽  
Surface Conditions ◽  
The Past ◽  
Empirical Relations

AbstractGlacial mass-balance reconstruction for a long-term time-scale requires knowledge of the relation between climate change and mass-balance fluctuations. A large number of mass-balance reconstructions since the beginning of the century are based on statistical relations between monthly meteorological data and mass balance. The question examined in this paper is: are these relationships reliable enough for long-term time-scale extrapolation? From the glacier de Sarennes long mass-balance observations series, we were surprised to discover large discrepancies between relations resulting from different time periods. The importance of the albedo in relation to ablation and mass balance is highlighted, and it is shown that it is impossible to ignore glacier-surface conditions in establishing the empirical relation between mass-balance fluctuations and climatic variation; to omit this parameter leads to incorrect results for mass-balance reconstruction in the past based on meteorological data.

scholarly journals Long-term records of glacier surface velocities in the Ötztal Alps (Austria)

2019 ◽  
Author(s):  
Martin Stocker-Waldhuber ◽  
Andrea Fischer ◽  
Kay Helfricht ◽  
Michael Kuhn
Keyword(s):  
Mass Balance ◽  
Glacier Mass Balance ◽  
Data Sets ◽  
Climatic Forcing ◽  
Glacier Surface ◽  
Ice Flow ◽  
Strong Indicator ◽  
Length Changes ◽  
Flow Velocities

Abstract. Climatic forcing affects glacier mass balance and ice flow dynamics on different time scales, resulting in length changes. Mass Balance and length changes are operationally used for glacier monitoring, whereas only a few time series of glacier dynamics have been recorded. With more than 100 years of measurements of ice flow velocities at stakes and stone lines on Hintereisferner and more than 50 years on Kesselwandferner, annual velocity and glacier fluctuation records have similar lengths. Subseasonal variations of ice flow velocities have been measured on Gepatschferner and Taschachferner for nearly a decade. The ice flow velocities on Hintereisferner and especially on Kesselwandferner show great variations between advancing and retreating periods, with magnitudes increasing from the highest to the lowest stakes, making ice flow records at ablation stakes a very sensitive indicator of glacier state. Since the end of the latest glacier advances from the 1970s to the 1980s, the ice flow velocities have decreased continuously, a strong indicator of the negative mass balances of the glaciers in recent decades. The velocity data sets of the four glaciers are available at https://doi.pangaea.de/10.1594/PANGAEA.896741.

scholarly journals Glaciers, snow and ski tourism in Austria’s changing climate

2011 ◽  
Vol 52 (58) ◽  
pp. 89-96 ◽  
Author(s):  
Andrea Fischer ◽  
Marc Olefs ◽  
Jakob Abermann
Keyword(s):  
Mass Balance ◽  
Snow Cover ◽  
Climate Data ◽  
Adaptation Measures ◽  
Glacier Surface ◽  
Ski Resort ◽  
Ski Resorts ◽  
Before And After ◽  
Natural Snow

AbstarctThis study illustrates the relevance of cryospheric changes for, and their impact on, ski tourism in Austria. The results of several case studies on snow reliability, snow production and mass balance in glacier ski resorts in the Ötz and Stubai valleys are summarized. Climate data from Obergurgl (1936ma.s.l.) in the Ötz valley are analyzed with respect to the amount and duration of natural snow cover and the possibility of snow production. A case study on Mittelbergferner focuses on the impacts of glacial recession on a ski resort and possible adaptation measures. From long-term glacier inventory and short-term mass-balance data, the effect of operating ski resorts on glaciers is investigated. At Obergurgl, the probability of both snow cover and snow production is >80% from December to March and decreases significantly in the months before and after this peak season. The interannual variability of snow cover and production is low during the main season and higher in other months. Year-to-year differences are larger than any long-term trend. Glacier ski resorts must adapt to shrinking glacial area and falling glacier surface. Covering the glacier with textiles reduces ablation by 60% and results in significantly less volume loss than on uncovered parts of the glacier. Neither the mass-balance comparison between groomed and ungroomed areas nor the comparison of long-term volume changes between 10 ski resort glaciers and 100 surrounding glaciers showed evidence for an impact of the operation of ski resorts on the glaciers.

scholarly journals Evolution of Ossoue Glacier (French Pyrenees) since the end of the Little Ice Age

2015 ◽  
Vol 9 (2) ◽  
pp. 2431-2494 ◽  
Author(s):  
R. Marti ◽  
S. Gascoin ◽  
T. Houet ◽  
O. Ribière ◽  
D. Laffly ◽  
...  
Keyword(s):  
Mass Balance ◽  
Little Ice Age ◽  
Atlantic Multidecadal Oscillation ◽  
Ablation Rate ◽  
Ice Age ◽  
Glacier Length ◽  
Geodetic Mass Balance ◽  
High Elevations ◽  
Topographic Surveys

Abstract. Long-term climate records are rare at high elevations in Southern Europe. Here, we reconstructed the evolution of Ossoue Glacier (42°46' N, 0.45 km2), located in the Pyrenees (3404 m a.s.l.), since the Little Ice Age (LIA). Glacier length, area, thickness and mass changes indicators were generated from historical datasets, topographic surveys, glaciological measurements (2001–2013), a GPR survey (2006) and stereoscopic satellite images (2013). The glacier has receded considerably since the end of the LIA, losing 40 % of its length and 60% of its area. Three periods of marked ice depletion can be identified: 1850–1890, 1928–1950 and 1983–2013, as well as two periods of stabilization or slightly growth: 1905–1928 and 1950–1983; these agree with climatic datasets (air temperature, precipitation, North Atlantic Oscillation, Atlantic Multidecadal Oscillation). In the early 2000s, the area of the glacier dropped below 50% of its area at the end of the LIA. Geodetic mass balance measurements over 1983–2013 indicated −30.1 ± 1.7 m w.e. (−1 m w.e. yr−1) whereas glaciological mass balance measurements show −17.36 ± 2.9 m w.e. (−1.45 m w.e. yr−1) over 2001–2013, resulting in a doubling of the ablation rate in the last decade. In 2013 the maximum ice thickness was 59 ± 10.3 m. Assuming that the current ablation rate stays constant, Ossoue Glacier will disappear midway through the 21st century.

20th-century climate change inferred from four long-term point observations of seasonal mass balance

2009 ◽  
Vol 50 (50) ◽  
pp. 207-214 ◽  
Author(s):  
Matthias Huss ◽  
Andreas Bauder
Keyword(s):  
Time Series ◽  
Mass Balance ◽  
20Th Century ◽  
Heat Budget ◽  
Balance Model ◽  
Climatic Forcing ◽  
Glacier Surface ◽  
Temperature Index ◽  
Air Temperatures

AbstractFour long-term time series of seasonal mass-balance observations, all starting in 1914, have been compiled for two stakes on Claridenfirn and one stake on Grosser Aletschgletscher and Silvrettagletscher, Switzerland. These data represent the longest records of mass balance worldwide. A mass-balance model based on the temperature-index approach is used to correct field data for varying observation dates and data gaps and to separate accumulation and ablation. The homogenized continuous 93 year time series cover most of the 20th century and enable us to investigate temporal, regional and altitudinal variability in mass balance and changes in the climatic forcing on glaciers. A high-altitude site shows summer balance trends opposite to those at three stakes located near the equilibrium line. Since 1975, melt rates have increased by 10%(10 a)−1 periods of enhanced climatic forcing are detected: 1943–53 and 1987–2007. The energy consumed for melt was higher in the 1940s despite lower air temperatures compared to the years since 1987. We find evidence for a change in the glacier surface heat budget, which has important implications for the long-term stability of degree-day factors in empirical temperature-index modelling.

scholarly journals Long-Term Deceleration of Glaciers in the Eastern Nyainqentanglha Mountains, Southeastern Tibetan Plateau, Revealed from Landsat Images

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2387 ◽  
Author(s):  
Xiyou Fu ◽  
Jianmin Zhou
Keyword(s):  
Mass Balance ◽  
Meteorological Data ◽  
Significant Rise ◽  
Surface Velocity ◽  
Landsat Images ◽  
Glacier Surface ◽  
Temperature And Precipitation ◽  
Glacier Velocity ◽  
The Relationship

Temperate glaciers are very sensitive to variations in temperature and precipitation, and thus represent a good indicator of climate change. By exploiting complete Landsat archives during periods of 1988–1990, 2000–2002 and 2014–2016, we derived three velocity maps of the temperate glaciers on the eastern Nyainqêntanglha Mountains in southeastern Tibetan to reveal the long-term changes of glacier surface velocity. Our results show that all the investigated glaciers experienced deceleration, with rates of deceleration varying from 4.15% to 29.8% per decade during the period from 1988–1990 to 2014–2016, showing heterogeneous deceleration patterns. A significant rise in temperature and an insignificant decrease in precipitation was found from the meteorological data of the nearby meteorological station. The region-wide deceleration of glaciers was, thus, attributed to the negative mass balance induced mainly by the rise in temperature. The averaged rates of deceleration for periods from 1988–1990 to 2000–2002 and from 2000–2002 to 2014–2016 are 20.97% and 22.02% per decade, respectively, indicating a nearly even speed of deceleration in velocities during study periods. The nearly even speed of deceleration in velocities and the accelerating mass loss trend from periods before the 2000s to after the 2000s highlighted the complexity of the relationship between mass balance and glacier velocity.

scholarly journals Meteorological controls on glacier mass balance: empirical relations suggested by measurements on glacier de Sarennes, France

1997 ◽  
Vol 43 (143) ◽  
pp. 131-137 ◽  
Author(s):  
C. Vincent ◽  
M. Vallon
Keyword(s):  
Mass Balance ◽  
Time Scale ◽  
Meteorological Data ◽  
Empirical Relation ◽  
Glacier Mass Balance ◽  
Glacier Surface ◽  
Surface Conditions ◽  
The Past ◽  
Empirical Relations

AbstractGlacial mass-balance reconstruction for a long-term time-scale requires knowledge of the relation between climate change and mass-balance fluctuations. A large number of mass-balance reconstructions since the beginning of the century are based on statistical relations between monthly meteorological data and mass balance. The question examined in this paper is: are these relationships reliable enough for long-term time-scale extrapolation? From the glacier de Sarennes long mass-balance observations series, we were surprised to discover large discrepancies between relations resulting from different time periods. The importance of the albedo in relation to ablation and mass balance is highlighted, and it is shown that it is impossible to ignore glacier-surface conditions in establishing the empirical relation between mass-balance fluctuations and climatic variation; to omit this parameter leads to incorrect results for mass-balance reconstruction in the past based on meteorological data.

scholarly journals Greenland surface mass-balance observations from the ice-sheet ablation area and local glaciers

2016 ◽  
Vol 62 (235) ◽  
pp. 861-887 ◽  
Author(s):  
HORST MACHGUTH ◽  
HENRIK H. THOMSEN ◽  
ANKER WEIDICK ◽  
ANDREAS P. AHLSTRØM ◽  
JAKOB ABERMANN ◽  
...  
Keyword(s):  
Mass Balance ◽  
East Coast ◽  
Grey Literature ◽  
Ice Sheet ◽  
Surface Mass Balance ◽  
Model Output ◽  
Glacier Surface ◽  
Surface Mass ◽  
Ablation Area

ABSTRACTGlacier surface mass-balance measurements on Greenland started more than a century ago, but no compilation exists of the observations from the ablation area of the ice sheet and local glaciers. Such data could be used in the evaluation of modelled surface mass balance, or to document changes in glacier melt independently from model output. Here, we present a comprehensive database of Greenland glacier surface mass-balance observations from the ablation area of the ice sheet and local glaciers. The database spans the 123 a from 1892 to 2015, contains a total of ~3000 measurements from 46 sites, and is openly accessible through the PROMICE web portal (http://www.promice.dk). For each measurement we provideX, YandZcoordinates, starting and ending dates as well as quality flags. We give sources for each entry and for all metadata. Two thirds of the data were collected from grey literature and unpublished archive documents. Roughly 60% of the measurements were performed by the Geological Survey of Denmark and Greenland (GEUS, previously GGU). The data cover all regions of Greenland except for the southernmost part of the east coast, but also emphasize the importance of long-term time series of which there are only two exceeding 20 a. We use the data to analyse uncertainties in point measurements of surface mass balance, as well as to estimate surface mass-balance profiles for most regions of Greenland.

scholarly journals Frontal ablation and temporal variations in surface velocity of Livingston Island ice cap, Antarctica

2013 ◽  
Vol 7 (4) ◽  
pp. 4207-4240 ◽  
Author(s):  
B. Osmanoglu ◽  
M. I. Corcuera ◽  
F. J. Navarro ◽  
M. Braun ◽  
R. Hock
Keyword(s):  
Mass Balance ◽  
Ablation Rate ◽  
Surface Velocity ◽  
South Shetland Islands ◽  
Ice Thickness ◽  
Western Coast ◽  
Glacier Surface ◽  
Ice Cap ◽  
Livingston Island ◽  
Frontal Ablation

Abstract. Frontal ablation from marine-terminating glaciers and ice caps covering the islands off the western coast of the Antarctic Peninsula is poorly known. Here we estimate the frontal ablation from the ice cap of Livingston Island, the second largest island in the South Shetland Islands archipelago, using glacier surface velocities obtained from intensity offset tracking of PALSAR-1 imagery and glacier ice thickness inferred from principles of glacier dynamics and calibrated against ground-penetrating radar (GPR) measurements of ice thickness. Using 21 SAR images acquired between October 2007 and January 2011, we obtain surface velocities of up to 250 m yr−1 and an average frontal ablation rate of about 509 ± 381 Mt yr−1, equivalent to a specific mass change of −0.7 ± 0.5 m w.e. yr−1 over the area of the ice cap (697 km2). A rough estimate of the surface mass balance of the ice cap gives 0.1 ± 0.1 m w.e. yr−1, resulting in a~total mass balance for Livingston Island ice cap of −0.6 ± 0.5 m w.e. yr−1. We find that frontal ablation and surface ablation contribute equal shares to total ablation. We also find large changes in frontal ablation rate (of ∼237 Mt yr−1) due to temporal variability in surface velocities. This highlights the importance of taking into account the seasonality in ice velocities when computing frontal ablation with a flux-gate approach.

scholarly journals Long-term records of glacier surface velocities in the Ötztal Alps (Austria)

2019 ◽  
Vol 11 (2) ◽  
pp. 705-715 ◽  
Author(s):  
Martin Stocker-Waldhuber ◽  
Andrea Fischer ◽  
Kay Helfricht ◽  
Michael Kuhn
Keyword(s):  
Mass Balance ◽  
Glacier Mass Balance ◽  
Climatic Forcing ◽  
Glacier Surface ◽  
Ice Flow ◽  
Strong Indicator ◽  
Glacier Length ◽  
Length Changes ◽  
Flow Velocities

Abstract. Climatic forcing affects glacier mass balance, which causes changes in ice flow dynamics and glacier length changes on different timescales. Mass balance and length changes are operationally used for glacier monitoring, whereas only a few time series of glacier dynamics have been recorded. Here we present a unique dataset of yearly averaged ice flow velocity measurements at stakes and stone lines covering more than 100 years on Hintereisferner and more than 50 years on Kesselwandferner. Moreover, the dataset contains sub-seasonal variations in ice flow from Gepatschferner and Taschachferner covering almost 10 years. The ice flow velocities on Hintereisferner and (especially) on Kesselwandferner show great variation between advancing and retreating periods, with magnitudes increasing from the stakes at higher elevations to the lower-elevated stakes, making ice flow records at ablation stakes a very sensitive indicator of glacier state. Since the end of the latest glacier advances from the 1970s to the 1980s, the ice flow velocities have decreased continuously, a strong indicator of the negative mass balances of the glaciers in recent decades. The velocity datasets of the four glaciers are available at https://doi.org/10.1594/PANGAEA.896741.

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