Surface elevation changes on Lachman Crags ice caps (north-eastern Antarctic Peninsula) since 1979 indicated by DEMs and ICESat data

ABSTRACTThe long-term warming on the Antarctic Peninsula in the second half of the 20th century prompted rapid retreat of glaciers on the peninsula and surrounding islands. Retreat accelerated until the beginning of the new millennium when the regional warming trend significantly decreased. The response of glaciers to the change in temperature trend has been observed around the northern part of the Antarctic Peninsula but the timing of the shift from the surface lowering to mass gain remains unclear. Using historical aerial photographs, DEMs and satellite altimeter data from ICESat, we estimate areal and surface elevation changes of two small ice caps in the northern part of James Ross Island over the last 39 years. The glacierized area on Lachman Crags decreased from 4.337 ± 0.037 to 3.581 ± 0.014 km2 (−17.4%) between 1979 and 2006 and then increased to 3.597 ± 0.047 km2 (0.4%) until 2016. Surface lowering observed on ice caps after 1979 continued at least until 2008 as indicated by the ICESat data. The change from the lowering trend to increase in glacier surface elevation probably occurred after the ablation season 2008/09, which ranks among the warmest summers in the north-eastern Antarctic Peninsula since the mid-20th century.

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Speedup and fracturing of George VI Ice Shelf, Antarctic Peninsula

The Cryosphere ◽

10.5194/tc-7-797-2013 ◽

2013 ◽

Vol 7 (3) ◽

pp. 797-816 ◽

Cited By ~ 20

Author(s):

T. O. Holt ◽

N. F. Glasser ◽

D. J. Quincey ◽

M. R. Siegfried

Keyword(s):

Antarctic Peninsula ◽

Structural Changes ◽

Surface Elevation ◽

Ice Shelf ◽

Ice Shelves ◽

The North ◽

Surface Elevation Change ◽

Elevation Changes ◽

Negative Surface ◽

The Antarctic

Abstract. George VI Ice Shelf (GVIIS) is located on the Antarctic Peninsula, a region where several ice shelves have undergone rapid breakup in response to atmospheric and oceanic warming. We use a combination of optical (Landsat), radar (ERS 1/2 SAR) and laser altimetry (GLAS) datasets to examine the response of GVIIS to environmental change and to offer an assessment on its future stability. The spatial and structural changes of GVIIS (ca. 1973 to ca. 2010) are mapped and surface velocities are calculated at different time periods (InSAR and optical feature tracking from 1989 to 2009) to document changes in the ice shelf's flow regime. Surface elevation changes are recorded between 2003 and 2008 using repeat track ICESat acquisitions. We note an increase in fracture extent and distribution at the south ice front, ice-shelf acceleration towards both the north and south ice fronts and spatially varied negative surface elevation change throughout, with greater variations observed towards the central and southern regions of the ice shelf. We propose that whilst GVIIS is in no imminent danger of collapse, it is vulnerable to ongoing atmospheric and oceanic warming and is more susceptible to breakup along its southern margin in ice preconditioned for further retreat.

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Speedup and fracturing of George VI Ice Shelf, Antarctic Peninsula

The Cryosphere Discussions ◽

10.5194/tcd-7-373-2013 ◽

2013 ◽

Vol 7 (1) ◽

pp. 373-417 ◽

Cited By ~ 3

Author(s):

T. O. Holt ◽

N. F. Glasser ◽

D. J. Quincey ◽

M. R. Siegfried

Keyword(s):

Antarctic Peninsula ◽

Structural Changes ◽

Surface Elevation ◽

Ice Shelf ◽

Ice Shelves ◽

The North ◽

Surface Elevation Change ◽

Elevation Changes ◽

Negative Surface ◽

The Antarctic

Abstract. George VI Ice Shelf (GVIIS) is located on the Antarctic Peninsula, a region where several ice shelves have undergone rapid breakup in response to atmospheric and oceanic warming. We use a combination of optical (Landsat), radar (ERS 1/2 SAR) and laser altimetry (GLAS) datasets to examine the response of GVIIS to environmental change and to offer an assessment on its future stability. The spatial and structural changes of GVIIS (ca. 1973 to ca. 2010) are mapped and surface velocities are calculated at different time periods (InSAR and optical feature tracking from 1989 to 2009) to document changes in the ice shelf's flow regime. Surface elevation changes are recorded between 2003 and 2008 using repeat track ICESat acquisitions. We note an increase in fracture extent and distribution at the south ice front, ice-shelf acceleration towards both the north and south ice fronts and spatially varied negative surface elevation change throughout, with greater variations observed towards the central and southern regions of the ice shelf. We propose that whilst GVIIS is in no imminent danger of collapse, it is vulnerable to on-going atmospheric and oceanic warming and is more susceptible to breakup along its southern margin in ice preconditioned for further retreat.

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The potential of TanDEM-X repeat acquisitions to monitor elevation and mass changes of Arctic and Antarctic glaciers

10.5194/egusphere-egu21-12383 ◽

2021 ◽

Author(s):

Christian Sommer ◽

Thorsten Seehaus ◽

Lukas Sochor ◽

Philipp Malz ◽

Matthias Braun

Keyword(s):

Antarctic Peninsula ◽

Greenland Ice Sheet ◽

The Arctic ◽

Radar Signal ◽

Altimeter Data ◽

Satellite Mission ◽

Laser Altimeter ◽

North Asia ◽

Elevation Changes ◽

The Antarctic

The large ice caps and glaciers of the northern and southern polar regions have the potential to contribute significantly to global sea-level rise, yet measurements of glacier mass changes in those regions are scarce and difficult due to harsh conditions and the size of Arctic and Antarctic glacier areas. Acquisitions of the synthetic aperture radar satellite mission TanDEM-X provide valuable insights into glacier dynamics in those regions as the X-band radar is independent from clouds and illumination and can resolve elevation changes of large glacierized areas as well as individual glaciers. We use specifically generated and coregistered digital elevation models (DEM) from repeated TanDEM-X data takes to derive glacier elevation changes between 2010 and 2020.For the Arctic regions, we already calculated elevation changes for the Russian Arctic archipelagos from TanDEM-X acquisitions (2000-2017). Currently, we are preparing similar TanDEM-X DEM differences for Arctic glaciers outside the Greenland ice sheet (Svalbard, Iceland, Alaska, Canadian Arctic, Scandinavia and North Asia). In contrast to the wide and smooth areas of the East and West Antarctic ice sheets, the steep topography of the Antarctic Peninsula strongly limits the application of altimeter data for accurately quantifying glacier mass changes. Therefore, we computed glacier mass changes along the Antarctic Peninsula by means of TanDEM-X data.Additionally, measurements of the IceSAT2 laser altimeter will be integrated in the analysis to improve the estimation of radar signal penetration into snow and firn and thereby reduce the elevation change and mass balance uncertainties.

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Multi-decadal ice-velocity and elevation changes of a monsoonal maritime glacier: Hailuogou glacier, China

Journal of Glaciology ◽

10.3189/002214310791190884 ◽

2010 ◽

Vol 56 (195) ◽

pp. 65-74 ◽

Cited By ~ 42

Author(s):

Yong Zhang ◽

Koji Fujita ◽

Shiyin Liu ◽

Qiao Liu ◽

Xin Wang

Keyword(s):

Thermal Emission ◽

Surface Elevation ◽

Aerial Photographs ◽

Differential Gps ◽

Glacier Surface ◽

Ablation Area ◽

Glacier Terminus ◽

Digital Elevation ◽

Elevation Changes ◽

Ice Velocity

AbstractDigital elevation models (DEMs) of the ablation area of Hailuogou glacier, China, produced from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data obtained in 2009, differential GPS (DGPS) data surveyed in 2008 and aerial photographs acquired in 1966 and 1989 are differenced to estimate long- and short-term glacier surface elevation change (dh/dt). The mean dh/dt of the ablation area over 43 years (1966–2009) is −1.1 ± 0.4 m a−1. Since 1989 the thinning has accelerated significantly. Ice velocities measured by DGPS at 28 fixed stakes implanted in the ablation area increase with distance from the glacier terminus, ranging from 41.0 m a−1 approaching the glacier terminus to a maximum of 205.0 m a−1 at the base of an icefall. Our results reveal that the overall average ice velocity in the ablation area has undergone significant temporal variability over the past several decades. Changes in glacier surface elevation in the ablation area result from the combined effects of climate change and glacier dynamics, which are driven by different factors for different regions and periods.

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Recent ice-surface-elevation changes of Fleming Glacier in response to the removal of the Wordie Ice Shelf, Antarctic Peninsula

Annals of Glaciology ◽

10.3189/172756410791392727 ◽

2010 ◽

Vol 51 (55) ◽

pp. 97-102 ◽

Cited By ~ 15

Author(s):

J. Wendt ◽

A. Rivera ◽

A. Wendt ◽

F. Bown ◽

R. Zamora ◽

...

Keyword(s):

Antarctic Peninsula ◽

Regional Climate ◽

Airborne Lidar ◽

Similar Data ◽

Ice Shelf ◽

International Polar Year ◽

Ice Flow ◽

Ice Shelves ◽

Elevation Changes ◽

The Antarctic

AbstractRegional climate warming has caused several ice shelves on the Antarctic Peninsula to retreat and ultimately collapse during recent decades. Glaciers flowing into these retreating ice shelves have responded with accelerating ice flow and thinning. The Wordie Ice Shelf on the west coast of the Antarctic Peninsula was reported to have undergone a major areal reduction before 1989. Since then, this ice shelf has continued to retreat and now very little floating ice remains. Little information is currently available regarding the dynamic response of the glaciers feeding the Wordie Ice Shelf, but we describe a Chilean International Polar Year project, initiated in 2007, targeted at studying the glacier dynamics in this area and their relationship to local meteorological conditions. Various data were collected during field campaigns to Fleming Glacier in the austral summers of 2007/08 and 2008/09. In situ measurements of ice-flow velocity first made in 1974 were repeated and these confirm satellite-based assessments that velocity on the glacier has increased by 40–50% since 1974. Airborne lidar data collected in December 2008 can be compared with similar data collected in 2004 in collaboration with NASA and the Chilean Navy. This comparison indicates continued thinning of the glacier, with increasing rates of thinning downstream, with a mean of 4.1 ± 0.2 m a−1 at the grounding line of the glacier. These comparisons give little indication that the glacier is achieving a new equilibrium.

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Geostatistical methods for mapping Antarctic ice surfaces at continental and regional scales

Annals of Glaciology ◽

10.3189/172756400781820714 ◽

2000 ◽

Vol 30 ◽

pp. 76-82 ◽

Cited By ~ 8

Author(s):

Ute Christina Herzfeld ◽

Ralf Stosius ◽

Marcus Schneider

Keyword(s):

Surface Elevation ◽

Altimeter Data ◽

Radar Altimeter ◽

Sea Level Changes ◽

Ice Streams ◽

Geostatistical Methods ◽

Ice Surface ◽

Geophysical Study ◽

Satellite Radar ◽

The Antarctic

AbstractThe Antarctic ice sheet plays a major role in the global system and the large ice streams discharging into the circumpolar sea represent its gateways to the world’s oceans. Satellite radar-altimeter data provide an opportunity for mapping surface elevation at kilometer resolution with meter accuracy. Geostatistical methods have been developed to accomplish this. We distinguish two goals in mapping the Antarctic ice surface: (a) construction of a continent-wide atlas of maps and digital terrain models, and (b) calculation of maps and models suitable for the study of individual glaciers, ice streams and ice shelves. The atlases consist of accurate maps of ice-surface elevation compiled from Seasat, Geosat and ERS-1 altimeter data, covering all of Antarctica surveyed by Geosat (to 72.1° S) and by ERS-1 (to 81.5° S). With a 3 km grid they are the highest-resolution maps available today with continent-wide coverage. The resolution permits geophysical study and facilitates monitoring of changes in ice-surface elevation and changes in flux across the ice-ocean boundary, which is essential for monitoring sea-level changes.

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Glacier surface elevation changes in Rongbuk Catchment of the Central Himalayas in the last four decades

10.5194/egusphere-egu2020-9125 ◽

2020 ◽

Author(s):

Qinghua Ye ◽

Wei Nie ◽

Yimin Chen ◽

Gang Li ◽

lide Tian ◽

...

Keyword(s):

Climate Modeling ◽

Melting Rate ◽

Surface Elevation ◽

High Mountain ◽

Glacier Surface ◽

Important Indicator ◽

Central Himalayas ◽

Glacier Melting ◽

Elevation Changes ◽

Thinning Rate

Glaciers in the central Himalayas are important water resources for the downstream habitants, and accelerating melting of the high mountain glaciers speed up with continuous warming. We summerized the geodetic glacier surface elevation changes (Dh) by 6 data sets at different time periods during 1974-2016 in RongbukCatchment(RC) on the northern slope of Mt. Qomolangma (Mt. Everest) in the Central Himalayas. The result showed that glacier Dh varied with altitude and time, from -0.29 &#177; 0.03m a-1 in 1974-2000, to -0.47 &#177;0.24 m a-1 in 1974-2006,and -0.48 &#177;0.16 m a-1 in 1974-2012. Dh increased to -0.60 &#177; 0.20 m a-1 in 2000-2012, then decreased to-0.46 &#177; 0.24 m a-1 in 2000-2014, and by -0.49 &#177; 0.08 m a-1 in 2000-2016, showing a diverse rate being up - down- a little up. However, it generally presented a similar glacier thinning rate by -0.46~-0.49 m a-1 in the last four decades since 1970s in RC according to Dh1974-2006, Dh1974-2012, Dh2000-2014, and Dh2000-2016. Local meteorological observations revealed that, to a first order, the glacier thinning rate was kept the same pace with the number of annual melting days (MD). In spite of the obviously arising summer air temperature (TS) in 2000-2014, a slowdown glacier melting rate by -391 mm w.e.a-1 occurred in 2000-2014 because of less melting days with more precipitation and less annual mean temperature(Tm). It shows that MD is another important indicator and controlling factor to evaluate or to estimate glacier melting trend, especially in hydrological or climate modeling.

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Multi-decadal glacier surface lowering in the Antarctic Peninsula

Geophysical Research Letters ◽

10.1029/2012gl052823 ◽

2012 ◽

Vol 39 (19) ◽

pp. n/a-n/a ◽

Cited By ~ 27

Author(s):

Matthias Kunz ◽

Matt A. King ◽

Jon P. Mills ◽

Pauline E. Miller ◽

Adrian J. Fox ◽

...

Keyword(s):

Antarctic Peninsula ◽

Glacier Surface ◽

The Antarctic

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Fifty Years of Tidewater Glacier Surface Elevation and Retreat Dynamics along the South-East Coast of Spitsbergen (Svalbard Archipelago)

Remote Sensing ◽

10.3390/rs14020354 ◽

2022 ◽

Vol 14 (2) ◽

pp. 354

Author(s):

Jan Kavan ◽

Guy D. Tallentire ◽

Mihail Demidionov ◽

Justyna Dudek ◽

Mateusz C. Strzelecki

Keyword(s):

East Coast ◽

Aerial Images ◽

Surface Elevation ◽

Glacier Surface ◽

Svalbard Archipelago ◽

Tidewater Glaciers ◽

Air Temperatures ◽

Frontal Zones ◽

Elevation Changes ◽

Norwegian Polar Institute

Tidewater glaciers on the east coast of Svalbard were examined for surface elevation changes and retreat rate. An archival digital elevation model (DEM) from 1970 (generated from aerial images by the Norwegian Polar Institute) in combination with recent ArcticDEM were used to compare the surface elevation changes of eleven glaciers. This approach was complemented by a retreat rate estimation based on the analysis of Landsat and Sentinel-2 images. In total, four of the 11 tidewater glaciers became land-based due to the retreat of their termini. The remaining tidewater glaciers retreated at an average annual retreat rate of 48 m year−1, and with range between 10–150 m year−1. All the glaciers studied experienced thinning in their frontal zones with maximum surface elevation loss exceeding 100 m in the ablation areas of three glaciers. In contrast to the massive retreat and thinning of the frontal zones, a minor increase in ice thickness was recorded in some accumulation areas of the glaciers, exceeding 10 m on three glaciers. The change in glacier geometry suggests an important shift in glacier dynamics over the last 50 years, which very likely reflects the overall trend of increasing air temperatures. Such changes in glacier geometry are common at surging glaciers in their quiescent phase. Surging was detected on two glaciers studied, and was documented by the glacier front readvance and massive surface thinning in high elevated areas.

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Enhanced glacial discharge from the eastern Antarctic Peninsula since the 1700s associated with a positive Southern Annular Mode

Scientific Reports ◽

10.1038/s41598-019-50897-4 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 6

Author(s):

W. A. Dickens ◽

G. Kuhn ◽

M. J. Leng ◽

A. G. C. Graham ◽

J. A. Dowdeswell ◽

...

Keyword(s):

Antarctic Peninsula ◽

Isotope Composition ◽

Southern Annular Mode ◽

Ice Shelf ◽

Annular Mode ◽

Ice Shelves ◽

The North ◽

North Eastern ◽

Glacial Discharge ◽

The Antarctic

Abstract The Antarctic Peninsula Ice Sheet is currently experiencing sustained and accelerating loss of ice. Determining when these changes were initiated and identifying the main drivers is hampered by the short instrumental record (1992 to present). Here we present a 6,250 year record of glacial discharge based on the oxygen isotope composition of diatoms (δ18Odiatom) from a marine core located at the north-eastern tip of the Antarctic Peninsula. We find that glacial discharge - sourced primarily from ice shelf and iceberg melting along the eastern Antarctic Peninsula – remained largely stable between ~6,250 to 1,620 cal. yr BP, with a slight increase in variability until ~720 cal. yr. BP. An increasing trend in glacial discharge occurs after 550 cal. yr BP (A.D. 1400), reaching levels unprecedented during the past 6,250 years after 244 cal. yr BP (A.D. 1706). A marked acceleration in the rate of glacial discharge is also observed in the early part of twentieth century (after A.D. 1912). Enhanced glacial discharge, particularly after the 1700s is linked to a positive Southern Annular Mode (SAM). We argue that a positive SAM drove stronger westerly winds, atmospheric warming and surface ablation on the eastern Antarctic Peninsula whilst simultaneously entraining more warm water into the Weddell Gyre, potentially increasing melting on the undersides of ice shelves. A possible implication of our data is that ice shelves in this region have been thinning for at least ~300 years, potentially predisposing them to collapse under intensified anthropogenic warming.

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