scholarly journals Detailed ice loss pattern in the northern Antarctic Peninsula: widespread decline driven by ice front retreats

2014 ◽  
Vol 8 (6) ◽  
pp. 2135-2145 ◽  
Author(s):  
T. A. Scambos ◽  
E. Berthier ◽  
T. Haran ◽  
C. A. Shuman ◽  
A. J. Cook ◽  
...  
Keyword(s):  
Mass Loss ◽  
Antarctic Peninsula ◽  
Snow Accumulation ◽  
Stereo Image ◽  
Western Coast ◽  
Elevation Change ◽  
Ice Shelf ◽  
Laser Altimetry ◽  
Ice Volume ◽  
Basin Scale

Abstract. The northern Antarctic Peninsula (nAP, < 66° S) is one of the most rapidly changing glaciated regions on earth, yet the spatial patterns of its ice mass loss at the glacier basin scale have to date been poorly documented. We use satellite laser altimetry and satellite stereo-image topography spanning 2001–2010, but primarily 2003–2008, to map ice elevation change and infer mass changes for 33 glacier basins covering the mainland and most large islands in the nAP. Rates of ice volume and ice mass change are 27.7± 8.6 km3 a−1 and 24.9± 7.8 Gt a−1, equal to −0.73 m a−1 w.e. for the study area. Mass loss is the highest for eastern glaciers affected by major ice shelf collapses in 1995 and 2002, where twelve glaciers account for 60% of the total imbalance. However, losses at smaller rates occur throughout the nAP, at both high and low elevation, despite increased snow accumulation along the western coast and ridge crest. We interpret the widespread mass loss to be driven by decades of ice front retreats on both sides of the nAP, and extended throughout the ice sheet due to the propagation of kinematic waves triggered at the fronts into the interior.

scholarly journals Detailed ice loss pattern in the northern Antarctic Peninsula: widespread decline driven by ice front retreats

2014 ◽  
Vol 8 (3) ◽  
pp. 3237-3261 ◽  
Author(s):  
T. A. Scambos ◽  
E. Berthier ◽  
T. Haran ◽  
C. A. Shuman ◽  
A. J. Cook ◽  
...  
Keyword(s):  
Mass Loss ◽  
Antarctic Peninsula ◽  
Snow Accumulation ◽  
Stereo Image ◽  
Western Coast ◽  
Ice Shelf ◽  
Ice Volume ◽  
Basin Scale ◽  
Almost All ◽  
High Elevations

Abstract. The northern Antarctic Peninsula (nAP, < 66° S) is one of the most rapidly changing glaciated regions on Earth, yet the spatial patterns of its ice mass loss at the glacier basin scale has to date been poorly documented. We use satellite laser altimetry and satellite stereo-image topography spanning 2001–2010 to map ice elevation change and infer mass changes for 33 glacier basins. Rates of ice volume and ice mass change are 27.7 ± 8.6 km3 a−1 and 24.9 ± 7.8 Gt a−1. This mass loss is compatible with recent gravimetric assessments, but it implies that almost all the gravimetry-inferred loss lies in the nAP sector. Mass loss is highest for eastern glaciers affected by major ice shelf collapses in 1995 and 2002, where twelve glaciers account for 60% of the total imbalance. However, losses at smaller rates occur throughout the nAP, and at high and low elevation, despite increased snow accumulation along the western coast and at high elevations. We interpret the widespread mass loss to be driven by decades of ice front retreats on both sides of the nAP, and by the propagation of kinematic waves triggered at the fronts into the interior.

scholarly journals 2001–2009 elevation and mass losses in the Larsen A and B embayments, Antarctic Peninsula

2011 ◽  
Vol 57 (204) ◽  
pp. 737-754 ◽  
Author(s):  
Christopher A. Shuman ◽  
Etienne Berthier ◽  
Ted A. Scambos
Keyword(s):  
Antarctic Peninsula ◽  
Loss Rate ◽  
Ice Shelf ◽  
Laser Altimetry ◽  
Ice Shelves ◽  
Ice Volume ◽  
Mass Losses ◽  
Digital Elevation ◽  
Modis Imagery ◽  
Elevation Changes

AbstractWe investigate the elevation and mass-balance response of tributary glaciers following the loss of the Larsen A and B ice shelves, Antarctic Peninsula (in 1995 and 2002 respectively). Our study uses MODIS imagery to track ice extent, and ASTER and SPOT5 digital elevation models (DEMs) plus ATM and ICESat laser altimetry to track elevation changes, spanning the period 2001–09. The measured Larsen B tributary glaciers (Hektoria, Green, Evans, Punchbowl, Jorum and Crane) lost up to 160 m in elevation during 2001–06, and thinning continued into 2009. Elevation changes were small for the more southerly Flask and Leppard Glaciers, which are still constrained by a Larsen B ice shelf remnant. In the northern embayment, continued thinning of >3 m a−1 on Drygalski Glacier, 14 years after the Larsen A ice shelf disintegrated, suggests that mass losses for the exposed Larsen B tributaries will continue for years into the future. Grounded ice volume losses exceed 13 km3 for Crane Glacier and 30 km3 for the Hektoria–Green–Evans glaciers. The combined mean loss rate for 2001–06 is at least 11.2 Gt a−1. Our values differ significantly from published mass-budget-based estimates for these embayments, but are a reasonable fraction of GRACE-derived rates for the region (∼40 Gt a−1).

scholarly journals Pervasive ice sheet mass loss reflects competing ocean and atmosphere processes

Science ◽  
2020 ◽  
Vol 368 (6496) ◽  
pp. 1239-1242 ◽  
Author(s):  
Ben Smith ◽  
Helen A. Fricker ◽  
Alex S. Gardner ◽  
Brooke Medley ◽  
Johan Nilsson ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Mass Loss ◽  
Sea Level ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Snow Accumulation ◽  
Mass Change ◽  
Laser Altimetry ◽  
Ice Shelves ◽  
Ice Cloud

Quantifying changes in Earth’s ice sheets and identifying the climate drivers are central to improving sea level projections. We provide unified estimates of grounded and floating ice mass change from 2003 to 2019 using NASA’s Ice, Cloud and land Elevation Satellite (ICESat) and ICESat-2 satellite laser altimetry. Our data reveal patterns likely linked to competing climate processes: Ice loss from coastal Greenland (increased surface melt), Antarctic ice shelves (increased ocean melting), and Greenland and Antarctic outlet glaciers (dynamic response to ocean melting) was partially compensated by mass gains over ice sheet interiors (increased snow accumulation). Losses outpaced gains, with grounded-ice loss from Greenland (200 billion tonnes per year) and Antarctica (118 billion tonnes per year) contributing 14 millimeters to sea level. Mass lost from West Antarctica’s ice shelves accounted for more than 30% of that region’s total.

scholarly journals Interannual changes of the floating ice shelf of Petermann Gletscher, North Greenland, from 2000 to 2012

2014 ◽  
Vol 60 (221) ◽  
pp. 489-499 ◽  
Author(s):  
Andreas Münchow ◽  
Laurie Padman ◽  
Helen A. Fricker
Keyword(s):  
Mass Loss ◽  
Three Dimensional ◽  
Greenland Ice Sheet ◽  
Altimeter Data ◽  
Ice Shelf ◽  
Laser Altimetry ◽  
Laser Altimeter ◽  
Airborne Laser ◽  
Tracking Surface ◽  
Basal Melting

AbstractPetermann Gletscher, northwest Greenland, drains 4% of the Greenland ice sheet into Nares Strait. Its floating ice shelf retreated from 81 to 48 km in length during two large calving events in 2010 and 2012. We document changes in the three-dimensional ice-shelf structure from 2000 to 2012, using repeated tracks of airborne laser altimetry and ice radio-echo sounding, ICESat laser altimetry and MODIS visible imagery. The recent ice-shelf velocity, measured by tracking surface features between flights in 2010 and 2011, is ~1.25 km a−1, ~15–30% faster than estimates made before 2010. The steady- state along-flow ice divergence represents 6.3 Gta−1 mass loss through basal melting (~5Gta−1) and surface melting and sublimation (~1.0Gta−1). Airborne laser altimeter data reveal thinning, both along a thin central channel and on the thicker ambient ice shelf. From 2007 to 2010 the ice shelf thinned by ~5 m a−1, which represents a non-steady mass loss of ~4.1 Gta−1. We suggest that thinning in the basal channels structurally weakened the ice shelf and may have played a role in the recent calving events.

scholarly journals The ice thickness distribution of Flask Glacier, Antarctic Peninsula, determined by combining radio-echo soundings, surface velocity data and flow modelling

2013 ◽  
Vol 54 (63) ◽  
pp. 18-24 ◽  
Author(s):  
Daniel Farinotti ◽  
Hugh Corr ◽  
G.Hilmar Gudmundsson
Keyword(s):  
Antarctic Peninsula ◽  
Thickness Distribution ◽  
Surface Velocity ◽  
Ice Thickness ◽  
Ice Shelf ◽  
Ice Flow ◽  
Ice Volume ◽  
Flow Modelling ◽  
Bedrock Topography ◽  
Sparse Measurements

AbstractAn interpolated bedrock topography is presented for Flask Glacier, one of the tributaries of the remnant part of the Larsen B ice shelf, Antarctic Peninsula. The ice thickness distribution is derived by combining direct but sparse measurements from airborne radio-echo soundings with indirect estimates obtained from ice-flow modelling. The ice-flow model is applied to a series of transverse profiles, and a first estimate of the bedrock is iteratively adjusted until agreement between modelled and measured surface velocities is achieved. The adjusted bedrock is then used to reinterpret the radio-echo soundings, and the recovered information used to further improve the estimate of the bedrock itself. The ice flux along the glacier center line provides an additional and independent constraint on the ice thickness. The resulting bedrock topography reveals a glacier bed situated mainly below sea level with sections having retrograde slope. The total ice volume of 120 ±15 km3 for the considered area of 215 km2 corresponds to an average ice thickness of 560 ± 70 m.

scholarly journals Impact of ice-shelf basal melting on inland ice-sheet thickness: a model study

2012 ◽  
Vol 53 (60) ◽  
pp. 129-135 ◽  
Author(s):  
Jürgen Determann ◽  
Malte Thoma ◽  
Klaus Grosfeld ◽  
Sylvia Massmann
Keyword(s):  
Mass Loss ◽  
Sea Level ◽  
Ice Sheet ◽  
Sheet Thickness ◽  
Ice Shelf ◽  
Ice Flow ◽  
Ice Shelves ◽  
Ice Volume ◽  
Basal Melting ◽  
The Impact

AbstractIce flow from the ice sheets to the ocean contains the maximum potential contributing to future eustatic sea-level rise. In Antarctica most mass fluxes occur via the extended ice-shelf regions covering more than half the Antarctic coastline. The most extended ice shelves are the Filchner–Ronne and Ross Ice Shelves, which contribute ~30% to the total mass loss caused by basal melting. Basal melt rates here show small to moderate average amplitudes of <0.5ma–1. By comparison, the smaller but most vulnerable ice shelves in the Amundsen and Bellinghausen Seas show much higher melt rates (up to 30 ma–1), but overall basal mass loss is comparably small due to the small size of the ice shelves. The pivotal question for both characteristic ice-shelf regions, however, is the impact of ocean melting, and, coevally, change in ice-shelf thickness, on the flow dynamics of the hinterland ice masses. In theory, ice-shelf back-pressure acts to stabilize the ice sheet, and thus the ice volume stored above sea level. We use the three-dimensional (3-D) thermomechanical ice-flow model RIMBAY to investigate the ice flow in a regularly shaped model domain, including ice-sheet, ice-shelf and open-ocean regions. By using melting scenarios for perturbation studies, we find a hysteresis-like behaviour. The experiments show that the system regains its initial state when perturbations are switched off. Average basal melt rates of up to 2 ma–1 as well as spatially variable melting calculated by our 3-D ocean model ROMBAX act as basal boundary conditions in time-dependent model studies. Changes in ice volume and grounding-line position are monitored after 1000 years of modelling and reveal mass losses of up to 40 Gt a–1.

scholarly journals Variable glacier response to atmospheric warming, northern Antarctic Peninsula, 1988–2009

2012 ◽  
Vol 6 (5) ◽  
pp. 1031-1048 ◽  
Author(s):  
B. J. Davies ◽  
J. L. Carrivick ◽  
N. F. Glasser ◽  
M. J. Hambrey ◽  
J. L. Smellie
Keyword(s):  
Antarctic Peninsula ◽  
Dynamic Equilibrium ◽  
Eastern Coast ◽  
Slope Aspect ◽  
Western Coast ◽  
Ice Shelf ◽  
Tidewater Glaciers ◽  
Temperature And Precipitation ◽  
Glacier Recession ◽  
James Ross Island

Abstract. The northern Antarctic Peninsula has recently exhibited ice-shelf disintegration, glacier recession and acceleration. However, the dynamic response of land-terminating, ice-shelf tributary and tidewater glaciers has not yet been quantified or assessed for variability, and there are sparse data for glacier classification, morphology, area, length or altitude. This paper firstly classifies the area, length, altitude, slope, aspect, geomorphology, type and hypsometry of 194 glaciers on Trinity Peninsula, Vega Island and James Ross Island in 2009 AD. Secondly, this paper documents glacier change 1988–2009. In 2009, the glacierised area was 8140±262 km2. From 1988–2001, 90% of glaciers receded, and from 2001–2009, 79% receded. This equates to an area change of −4.4% for Trinity Peninsula eastern coast glaciers, −0.6% for western coast glaciers, and −35.0% for ice-shelf tributary glaciers from 1988–2001. Tidewater glaciers on the drier, cooler eastern Trinity Peninsula experienced fastest shrinkage from 1988–2001, with limited frontal change after 2001. Glaciers on the western Trinity Peninsula shrank less than those on the east. Land-terminating glaciers on James Ross Island shrank fastest in the period 1988–2001. This east-west difference is largely a result of orographic temperature and precipitation gradients across the Antarctic Peninsula, with warming temperatures affecting the precipitation-starved glaciers on the eastern coast more than on the western coast. Reduced shrinkage on the western Peninsula may be a result of higher snowfall, perhaps in conjunction with the fact that these glaciers are mostly grounded. Rates of area loss on the eastern side of Trinity Peninsula are slowing, which we attribute to the floating ice tongues receding into the fjords and reaching a new dynamic equilibrium. The rapid shrinkage of tidewater glaciers on James Ross Island is likely to continue because of their low elevations and flat profiles. In contrast, the higher and steeper tidewater glaciers on the eastern Antarctic Peninsula will attain more stable frontal positions after low-lying ablation areas are removed, reaching equilibrium more quickly.

scholarly journals First Glaciological Studies on the James Ross Island Ice Cap, Antarctic Peninsula

1981 ◽  
Vol 27 (97) ◽  
pp. 371-379 ◽  
Author(s):  
A. J. Aristarain ◽  
R. Delmas
Keyword(s):  
Antarctic Peninsula ◽  
Accumulation Rate ◽  
Snow Accumulation ◽  
Sea Salt ◽  
Deuterium Content ◽  
Western Coast ◽  
Conductivity Measurements ◽  
Ice Cap ◽  
Climatic Regime ◽  
James Ross Island

AbstractA 10 m deep core and a 2 m pit were achieved in December 1977 on the ice cap of James Ross Island (Antarctic Peninsula) 3 km westward of the main dome at an altitude of 1 500 m. The 10 m temperature was −14.2°C. The core was cut into 106 samples which have been used for density, total β radioactivity, electroconductivity, and deuterium-content measurements. The age at the bottom of the bore hole has been estimated to be 1 965±1 year and a mean annual snow accumulation rate 37.7±3.0 g cm−2a−1is calculated over the last 13 years. By comparing our results with those obtained in other areas of the Peninsula, the climate of the upper part of James Ross Island seems to follow the climatic regime of the western coast. A preliminary chemical analysis of the pit samples leads us to conclude that the snow impurities are mainly sea-salt derived. The conductivity measurements show a clearly defined peak at the end of 1967 which could be linked with the volcanic eruption of the Deception Island volcano in December 1967. The interest of the studied location is discussed in view of further more extended glaciological investigations and particularly a possible coring to the bottom.

scholarly journals Glacier calving front extraction from TanDEM-X DEM products of the Antarctic Peninsula

2020 ◽  
Author(s):  
Yuting Dong ◽  
Lukas Krieger ◽  
Dana Floricioiu ◽  
Ji Zhao
Keyword(s):  
Remote Sensing ◽  
Mass Loss ◽  
Antarctic Peninsula ◽  
Open Water ◽  
Time Stamp ◽  
Front Line ◽  
Ice Shelf ◽  
Ice Shelves ◽  
Geodetic Mass Balance ◽  
The Antarctic

&lt;p&gt;The Antarctic Peninsula (AP) is one of the most dynamic Polar regions and is experiencing fast mass loss. In order to quantify the mass changes of the AP and the associated sea level rise, an accurate estimate of its contemporary mass change is essential. The calving front location (CFL) is one important parameter to measure the geodetic mass balance or the dynamic mass loss of outlet glaciers. In order to quantify the mass change of Antarctic Peninsula glaciers on regional or individual glacier scales, the CFL with high spatial resolution is required. Because the Antarctic Peninsula has long, narrow coastlines, it is extremely time-consuming to delineate the detailed CFL from optical or SAR remote sensing images manually. Furthermore, it is also challenging for automatic algorithms to detect the whole glacier calving front line of AP considering the similarity of spectral and backscattering response of sea ice, grounded ice and m&amp;#233;lange. Currently the most up-to-date coastal product covering the entire AP, which is provided by the Antarctic Digital Database (ADD), is manually delineated with all of the available remote sensing imagery acquired in various years. A frequently updated CFL product for the entire AP coastline is not available.&lt;/p&gt;&lt;p&gt;Therefore, we propose an efficient method to extract the current coastline of AP from bi-static TanDEM-X DEM products, including the 12 m TanDEM-X global DEM and newly processed RawDEMs with a precise time stamp. &amp;#160;The CFL between grounded ice or ice shelves and the ice m&amp;#233;lange or open water is characterized by strong elevation gradients. Besides, the grounded ice and the ice shelf show smoother and more continuous elevation values in the TanDEM-X DEM while the ice m&amp;#233;lange and open water are noisier. Hence the ice m&amp;#233;lange at the CFL may look similar to grounded ice or ice shelves in optical and SAR images but can be distinguished in the TanDEM-X interferometric DEM. In our work, we combine elevation and elevation gradient information to separate grounded ice/ice shelves and ice m&amp;#233;lange. Afterwards, terrain analysis and morphological operations are applied to remove the residual ice m&amp;#233;lange pixels in the segmented image.&lt;/p&gt;&lt;p&gt;The TanDEM-X global DEM covering AP is a consistent, timely and high-precision DEM, which was generated from the bistatic InSAR data acquired by the TanDEM-X mission during austral winters 2013 and 2014. Thus our coastline of AP extracted from the 12 m TanDEM-X global DEM will correspond to the CFL of outlet glaciers of years 2013/2014. Furthermore, the CFL extracted from TanDEM-X RawDEMs with a particular time stamp can be used for geodetic mass balance calculation during different time periods. The extracted glacier calving front line reveals the potential of the high resolution height information in assisting the separation of grounded ice/ice shelf and ice m&amp;#233;lange. The resulting glacier calving front line product of AP will be validated with the geocoded TanDEM-X backscattering amplitude images acquired at the date closest to the time stamp of the DEM tile and with the Antarctic coastline provided by the ADD.&lt;/p&gt;

scholarly journals Evidence of recent climatic warming on the eastern Antarctic Peninsula

1998 ◽  
Vol 27 ◽  
pp. 628-632 ◽  
Author(s):  
Pedro Skvarca ◽  
Wolfgang Rack ◽  
Helmut Rott ◽  
Teresa Ibarzábal Y Donángelo
Keyword(s):  
Antarctic Peninsula ◽  
Warming Trend ◽  
Western Coast ◽  
Ice Shelf ◽  
Orkney Islands ◽  
Air Temperatures ◽  
Recent Climate ◽  
Summer Temperatures ◽  
The Antarctic ◽  
Larsen Ice Shelf

Air temperatures at the Marambio (MAR), Esperanza (ESP) and Matienzo (MAT) stations have been analyzed to investigate recent climate change on the eastern part of the Antarctic Peninsula. They are compared with data from the Oreadas station on the South Orkney Islands, the longest record available in Antarctica, and from the Faraday (FAR) station on the western coast of the Peninsula. Though the interannual variability is comparatively high and the stations are located in different climatic regimes, a pronounced warming trend shows up in all records. At MAR a temperature increase of 1.5°C has been observed since the beginning of the record in 1971. This is of similar magnitude to the increase at FAR on the west coast, which was 2.5°C for the longer period since 1945. The steady retreat and collapse of the northern Larsen Ice Shelf (LIS) coincided with this warming trend. of particular importance for the ice-shelf mass balance in this region are the summer temperatures which show a statistically significant warming trend at MAR and ESP. The representativity of the summer temperatures of MAR for northern LIS is confirmed by intercomparison with the parallel measurements at MAT which is located on the ice shelf.

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