Measured Velocities of Interior East Antarctica and the State of Mass Balance Within the I.A.G.P. Area

AbstractRecent measurements of accumulation and ice velocity made in the interior of East Antarctica indicate that a large sector between longitudes 80° E. and 135° E. and north of latitude 80° S. has close to a zero net mass budget. This sector is within the study area for the International Antarctic Glaciological Project (I.A.G.P.) and covers a major portion of the area indicated for projects of special emphasis. Velocity measurements were made at a number of points on a traverse route from Mirny (lat. 66° 33′ S., long. 93°00′ E.) on the coast Dome “C” (lat. 74° 40′ S., long. 124° 00′ E.), in the interior. Accumulation measurements were made along this and other traverse routes, extending as far as Vostok (lat. 78° 28′ S., long. 106° 50′ E.), by a number of methods. These included stake, stratigraphic, isotopic, and totalβ-decay observations. The better accumulation data have allowed a review of the total mass input to be made. The true mass budget has been estimated by comparing velocities, calculated assuming a zero net mass budget with measured velocities along the traverse routes and on a number of the outlet glaciers. For this purpose the area was divided into a number of drainage basins according to outlet at the coast. The area of about 106km2and 150 Gt a−1flux input is drained primarily by three glacier systems of which the Totten accounts for 40% of the flux from 55% of the area; the Vanderford 20% from 15%; and the Scott/Denman 20% from 20%.

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Measured Velocities of Interior East Antarctica and the State of Mass Balance Within the I.A.G.P. Area

Journal of Glaciology ◽

10.3189/s0022143000014660 ◽

1979 ◽

Vol 24 (90) ◽

pp. 77-87 ◽

Cited By ~ 1

Author(s):

N. W. Young

Keyword(s):

Mass Balance ◽

Total Mass ◽

East Antarctica ◽

Velocity Measurements ◽

Drainage Basins ◽

Mass Budget ◽

Large Sector ◽

Ice Velocity ◽

True Mass ◽

Made In

AbstractRecent measurements of accumulation and ice velocity made in the interior of East Antarctica indicate that a large sector between longitudes 80° E. and 135° E. and north of latitude 80° S. has close to a zero net mass budget. This sector is within the study area for the International Antarctic Glaciological Project (I.A.G.P.) and covers a major portion of the area indicated for projects of special emphasis. Velocity measurements were made at a number of points on a traverse route from Mirny (lat. 66° 33′ S., long. 93°00′ E.) on the coast Dome “C” (lat. 74° 40′ S., long. 124° 00′ E.), in the interior. Accumulation measurements were made along this and other traverse routes, extending as far as Vostok (lat. 78° 28′ S., long. 106° 50′ E.), by a number of methods. These included stake, stratigraphic, isotopic, and total β-decay observations. The better accumulation data have allowed a review of the total mass input to be made. The true mass budget has been estimated by comparing velocities, calculated assuming a zero net mass budget with measured velocities along the traverse routes and on a number of the outlet glaciers. For this purpose the area was divided into a number of drainage basins according to outlet at the coast. The area of about 106 km2 and 150 Gt a−1 flux input is drained primarily by three glacier systems of which the Totten accounts for 40% of the flux from 55% of the area; the Vanderford 20% from 15%; and the Scott/Denman 20% from 20%.

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An international palaeo-environmental project at Paakitsoq, West Greenland

Rapport Grønlands Geologiske Undersøgelse ◽

10.34194/rapggu.v165.8285 ◽

1995 ◽

Vol 165 ◽

pp. 88-92

Author(s):

H.H Thomsen ◽

P.E Biscaye ◽

J.C Bourgeois ◽

C.E Bøggild ◽

H Oerter ◽

...

Keyword(s):

Mass Balance ◽

Ice Core ◽

Environmental Parameters ◽

Glacial Cycle ◽

Joint Project ◽

Large Samples ◽

Ice Velocity ◽

Age Range ◽

Made In ◽

The Last Glacial

The easily accessible ice at Paakitsoq offers a favourable opportunity to study the major climatic events that occurred during the last glacial cycle, since large samples of ice with a limited age-range can be obtained. In this sense the ice margin record is an alternative to the deep ice-core records where the number of environmental parameters that can be studied is limited by the amount of ice available, each parameter requiring a certain amount of ice for its analysis (Reeh et al., 1993). This possibility has attracted the attention of scientists working with environmental parameters requiring large ice samples. A Danish, American, Canadian and German joint project was therefore initiated, and in April 1994 a programme of retrieving ice samples for studies of pollen, dust, chemistry, textures, fabric and visual stratigraphy was carried out. Furthermore, measurements of mass balance, ice velocity and deformation were made. In addition to the possibility of studying the variation of environmental parameters over a full glacial cycle, the project will also support the establishment of a better chronology along the Paakitsoq profile.

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Closing the mass budget of a tidewater glacier: the example of Kronebreen, Svalbard

Journal of Glaciology ◽

10.1017/jog.2018.98 ◽

2019 ◽

Vol 65 (249) ◽

pp. 136-148 ◽

Cited By ~ 6

Author(s):

CESAR DESCHAMPS-BERGER ◽

CHRISTOPHER NUTH ◽

WARD VAN PELT ◽

ETIENNE BERTHIER ◽

JACK KOHLER ◽

...

Keyword(s):

Remote Sensing ◽

Mass Balance ◽

Total Mass ◽

Continuity Equation ◽

Recent Period ◽

Mass Budget ◽

Tidewater Glacier ◽

Geodetic Mass Balance ◽

Frontal Ablation

ABSTRACTIn this study, we combine remote sensing, in situ and model-derived datasets from 1966 to 2014 to calculate the mass-balance components of Kronebreen, a fast-flowing tidewater glacier in Svalbard. For the well-surveyed period 2009–2014, we are able to close the glacier mass budget within the prescribed errors. During these 5 years, the glacier geodetic mass balance was −0.69 ± 0.12 m w.e. a−1, while the mass budget method led to a total mass balance of −0.92 ± 0.16 m w.e. a−1, as a consequence of a strong frontal ablation (−0.78 ± 0.11 m w.e. a−1), and a slightly negative climatic mass balance (−0.14 ± 0.11 m w.e. a−1). The trend towards more negative climatic mass balance between 1966–1990 (+0.20 ± 0.05 m w.e. a−1) and 2009–2014 is not reflected in the geodetic mass balance trend. Therefore, we suspect a reduction in ice-discharge in the most recent period. Yet, these multidecadal changes in ice-discharge cannot be measured from the available observations and thus are only estimated with relatively large errors as a residual of the mass continuity equation. Our study presents the multidecadal evolution of the dynamics and mass balance of a tidewater glacier and illustrates the errors introduced by inferring one unmeasured mass-balance component from the others.

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Changes in glaciers in Hidden Valley, Mukut Himal, Nepal Himalayas, from 1974 to 1994

Journal of Glaciology ◽

10.3189/s002214300003519x ◽

1997 ◽

Vol 43 (145) ◽

pp. 583-588 ◽

Cited By ~ 5

Author(s):

Koji Fujita ◽

Masayoshi Nakawo ◽

Yoshiyuki Fujii ◽

Prem Paudyal

Keyword(s):

Mass Balance ◽

Total Mass ◽

Volume Loss ◽

Hidden Valley ◽

The World ◽

Made In

AbstractGlaciological investigations were carried out in 1994 on the glaciers in Hidden Valley, Mukut Himal, Nepal Himalayas, in order to make a comparison with observations made in 1974. Most of the glaciers were found to have retreated by 30–60 m in terminus elevation over the 20 years between the two studies. Rikha Samba Glacier, the longest glacier in the valley, has retreated by about 200m. The areal average of the amount of surface lowering and the volume loss of the glacier was estimated to be 12.6 m ice equivalent and 13% of the total mass, respectively. The annual mass balance of −0.35 m a−1 water equivalent was obtained as an average for 20 years, which is one of the largest negative values amongst small glaciers of the world.

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The Equation of Continuity and its Application to the Ice Sheet Near “byrd” Station, Antarctica

Journal of Glaciology ◽

10.1017/s0022143000021055 ◽

1977 ◽

Vol 18 (80) ◽

pp. 359-371 ◽

Cited By ~ 49

Author(s):

I. M. Whillans

Keyword(s):

Steady State ◽

Mass Balance ◽

Ice Sheet ◽

Ice Thickness ◽

Surface Mass Balance ◽

Velocity Measurements ◽

Ice Flow ◽

Measured Velocity ◽

Surface Mass ◽

Ice Velocity

Abstract The continuity relationship that is often used in the study of ice sheets and ice shelves is developed by integrating the equation of continuity through the ice thickness. This equation is then integrated again with respect to horizontal distance from an ice divide, showing that the difference between the true ice velocity and the balance velocity, which is defined, is a measure of the time chance of the mass of a column through the ice thickness. The relationship is applied using data from along the “Byrd” station strain network, Antarctica. This region is found to be thinning slowly (0.03 m a−1 of ice of mean density) and uniformly, but it is still close to steady-state. The calculations would show a larger thinning rate if bottom sliding contributed more to the ice movement and integral shear contributed less, but the “Byrd” station bore-hole tilting results of Garfield and Ueda (1975, 1976), together with surface velocity measurements at “Byrd” station, indicate that most of the ice flow is by deformation within the ice mass. This large amount of internal deformation is more than that predicted by most “flow laws”, probably because of the strongly oriented ice-crystal fabric in the ice sheet. The cause of ice thinning is probably decreased surface mass balance beginning before A.D. 1550. The consistent relationship between measured velocity and balance velocity indicates that the ice flow is simple and that flow lines are in the same direction at depth as at the surface when considered smoothed over a distance of 10 km. Because the ice sheet is at present thinning, the balance velocity, calculated only from flow line and surface mass-balance data, and the somewhat mistaken assumption of steady-state is 15% less than the true ice velocity. This rather small difference confirms the use of balance-velocity estimates where velocity measurements are not available.

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Historical behaviour of Dome C and Talos Dome (East Antarctica) as investigated by snow accumulation and ice velocity measurements

Global and Planetary Change ◽

10.1016/j.gloplacha.2007.08.002 ◽

2008 ◽

Vol 60 (3-4) ◽

pp. 576-588 ◽

Cited By ~ 49

Author(s):

Stefano Urbini ◽

Massimo Frezzotti ◽

Stefano Gandolfi ◽

Christian Vincent ◽

Claudio Scarchilli ◽

...

Keyword(s):

Snow Accumulation ◽

East Antarctica ◽

Velocity Measurements ◽

Ice Velocity

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ICE FLOW VELOCITY MAPPING IN EAST ANTARCTICA USING HISTORICAL IMAGES FROM 1960s TO 1980s: RECENT PROGRESS

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xliii-b3-2021-491-2021 ◽

2021 ◽

Vol XLIII-B3-2021 ◽

pp. 491-496

Author(s):

S. Luo ◽

Y. Cheng ◽

Z. Li ◽

Y. Wang ◽

K. Wang ◽

...

Keyword(s):

Mass Balance ◽

Flow Velocity ◽

East Antarctica ◽

Input Output ◽

Velocity Mapping ◽

Ice Flow ◽

Optical Images ◽

Elevation Changes ◽

Ice Velocity ◽

Surface Ice

Abstract. Recent research indicates that the estimated elevation changes and associated mass balance in East Antarctica are of some degree of uncertainty; a light accumulation has occurred in its vast inland regions, while mass loss in Wilkes Land appears significant. It is necessary to study the mass change trend in the context of a long period of the East Antarctic Ice Sheet (EAIS). The input-output method based on surface ice flow velocity and ice thickness is one of the most important ways to estimate the mass balance, which can provide longer-term knowledge of mass balance because of the availability of the early satellites in 1960s. In this study, we briefly describe the method of extracting ice velocity based on the historical optical images from 1960s to 1980s. Based on the draft ice velocity map of the EAIS using this method, we conduct a series of validation experiments, including comparisons with in-situ measurement, existing historical maps and rock outcrop dataset. Finally, we use the input-output method to estimate mass balance in some regions of EAIS using the generated velocity map.

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Changes in glaciers in Hidden Valley, Mukut Himal, Nepal Himalayas, from 1974 to 1994

Journal of Glaciology ◽

10.1017/s002214300003519x ◽

1997 ◽

Vol 43 (145) ◽

pp. 583-588 ◽

Cited By ~ 46

Author(s):

Koji Fujita ◽

Masayoshi Nakawo ◽

Yoshiyuki Fujii ◽

Prem Paudyal

Keyword(s):

Mass Balance ◽

Total Mass ◽

Volume Loss ◽

Hidden Valley ◽

The World ◽

Made In

AbstractGlaciological investigations were carried out in 1994 on the glaciers in Hidden Valley, Mukut Himal, Nepal Himalayas, in order to make a comparison with observations made in 1974. Most of the glaciers were found to have retreated by 30–60 m in terminus elevation over the 20 years between the two studies. Rikha Samba Glacier, the longest glacier in the valley, has retreated by about 200m. The areal average of the amount of surface lowering and the volume loss of the glacier was estimated to be 12.6 m ice equivalent and 13% of the total mass, respectively. The annual mass balance of −0.35 m a−1water equivalent was obtained as an average for 20 years, which is one of the largest negative values amongst small glaciers of the world.

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The Equation of Continuity and its Application to the Ice Sheet Near “byrd” Station, Antarctica

Journal of Glaciology ◽

10.3189/s0022143000021055 ◽

1977 ◽

Vol 18 (80) ◽

pp. 359-371 ◽

Cited By ~ 1

Author(s):

I. M. Whillans

Keyword(s):

Steady State ◽

Mass Balance ◽

Ice Sheet ◽

Ice Thickness ◽

Surface Mass Balance ◽

Velocity Measurements ◽

Ice Flow ◽

Measured Velocity ◽

Surface Mass ◽

Ice Velocity

AbstractThe continuity relationship that is often used in the study of ice sheets and ice shelves is developed by integrating the equation of continuity through the ice thickness. This equation is then integrated again with respect to horizontal distance from an ice divide, showing that the difference between the true ice velocity and the balance velocity, which is defined, is a measure of the time chance of the mass of a column through the ice thickness.The relationship is applied using data from along the “Byrd” station strain network, Antarctica. This region is found to be thinning slowly (0.03 m a−1 of ice of mean density) and uniformly, but it is still close to steady-state. The calculations would show a larger thinning rate if bottom sliding contributed more to the ice movement and integral shear contributed less, but the “Byrd” station bore-hole tilting results of Garfield and Ueda (1975, 1976), together with surface velocity measurements at “Byrd” station, indicate that most of the ice flow is by deformation within the ice mass. This large amount of internal deformation is more than that predicted by most “flow laws”, probably because of the strongly oriented ice-crystal fabric in the ice sheet. The cause of ice thinning is probably decreased surface mass balance beginning before A.D. 1550.The consistent relationship between measured velocity and balance velocity indicates that the ice flow is simple and that flow lines are in the same direction at depth as at the surface when considered smoothed over a distance of 10 km. Because the ice sheet is at present thinning, the balance velocity, calculated only from flow line and surface mass-balance data, and the somewhat mistaken assumption of steady-state is 15% less than the true ice velocity. This rather small difference confirms the use of balance-velocity estimates where velocity measurements are not available.

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