Surface elevation contours of greenland and Antarctic Ice Sheets

1983 ◽  
Vol 88 (C3) ◽  
pp. 1589 ◽  
Author(s):  
H. Jay Zwally ◽  
R. A. Bindschadler ◽  
A. C. Brenner ◽  
T. V. Martin ◽  
R. H. Thomas
Author(s):  
G. S. Babonis ◽  
B. Csatho ◽  
T. Schenk

During the past few decades the Greenland and Antarctic ice sheets have lost ice at accelerating rates, caused by increasing surface temperature. The melting of the two big ice sheets has a big impact on global sea level rise. If the ice sheets would melt down entirely, the sea level would rise more than 60 m. Even a much smaller rise would cause dramatic damage along coastal regions. In this paper we report about a major upgrade of surface elevation changes derived from laser altimetry data, acquired by NASA’s Ice, Cloud and land Elevation Satellite mission (ICESat) and airborne laser campaigns, such as Airborne Topographic Mapper (ATM) and Land, Vegetation and Ice Sensor (LVIS). For detecting changes in ice sheet elevations we have developed the Surface Elevation Reconstruction And Change detection (SERAC) method. It computes elevation changes of small surface patches by keeping the surface shape constant and considering the absolute values as surface elevations. We report about important upgrades of earlier results, for example the inclusion of local ice caps and the temporal extension from 1993 to 2014 for the Greenland Ice Sheet and for a comprehensive reconstruction of ice thickness and mass changes for the Antarctic Ice Sheets.


Author(s):  
G. S. Babonis ◽  
B. Csatho ◽  
T. Schenk

During the past few decades the Greenland and Antarctic ice sheets have lost ice at accelerating rates, caused by increasing surface temperature. The melting of the two big ice sheets has a big impact on global sea level rise. If the ice sheets would melt down entirely, the sea level would rise more than 60 m. Even a much smaller rise would cause dramatic damage along coastal regions. In this paper we report about a major upgrade of surface elevation changes derived from laser altimetry data, acquired by NASA’s Ice, Cloud and land Elevation Satellite mission (ICESat) and airborne laser campaigns, such as Airborne Topographic Mapper (ATM) and Land, Vegetation and Ice Sensor (LVIS). For detecting changes in ice sheet elevations we have developed the Surface Elevation Reconstruction And Change detection (SERAC) method. It computes elevation changes of small surface patches by keeping the surface shape constant and considering the absolute values as surface elevations. We report about important upgrades of earlier results, for example the inclusion of local ice caps and the temporal extension from 1993 to 2014 for the Greenland Ice Sheet and for a comprehensive reconstruction of ice thickness and mass changes for the Antarctic Ice Sheets.


The conclusion of this two day meeting finds us with a very great deal on which we may congratulate ourselves. In the first place there is the extremely large attendance, embracing scientists of all ages, and graced and illuminated by the attendance of many overseas colleagues of experience and distinction. In the second place we have the great range of scientific disciplines that are now applied to our field of study, many now extremely sophisticated, and the corresponding extension of Quaternary Studies into fields of evidence not hitherto exploited. In the early days of palynology of laminated lake sediments one could write of deciphering the ‘annals of the lakes’, but beginning by reading the record of lakes, peat bogs, coastal, fluviatile, glacial and periglacial geology, we have progressed to translating the long and detailed records of the deep oceans, and now the encapsulated history of the Arctic and Antarctic ice sheets. We have been introduced to the marvellous potential of the great CLIMAP Project, and all [biologists in the British Isles at least will now have to consider whether their hypotheses of past biotic history satisfy the new principle that we can all see emerging as ‘McIntyre’s Gate’.


2020 ◽  
Author(s):  
Martim Mas e Braga ◽  
Jorge Bernales ◽  
Matthias Prange ◽  
Arjen P. Stroeven ◽  
Irina Rogozhina

1970 ◽  
Vol 9 (56) ◽  
pp. 263-268 ◽  
Author(s):  
F. Loewe

At places with an annual mean temperature lower than −20°C on the Greenland and Antarctic ice sheets, the temperature at a depth of 10 m is close to the annual mean at the surface and at the level of the meteorological shelter. With temperatures higher than about −35°C the size and sign of the différences vary. With lower temperatures the 10 m temperature becomes increasingly lower than the air temperature, at the coldest Antarctic station, “Plateau”, by nearly 4 deg.


2018 ◽  
Vol 8 (12) ◽  
pp. 1053-1061 ◽  
Author(s):  
Frank Pattyn ◽  
Catherine Ritz ◽  
Edward Hanna ◽  
Xylar Asay-Davis ◽  
Rob DeConto ◽  
...  

2014 ◽  
Vol 26 (6) ◽  
pp. 724-741 ◽  
Author(s):  
Stewart S.R. Jamieson ◽  
Chris R. Stokes ◽  
Neil Ross ◽  
David M. Rippin ◽  
Robert G. Bingham ◽  
...  

AbstractIn 1976, David Sugden and Brian John developed a classification for Antarctic landscapes of glacial erosion based upon exposed and eroded coastal topography, providing insight into the past glacial dynamics of the Antarctic ice sheets. We extend this classification to cover the continental interior of Antarctica by analysing the hypsometry of the subglacial landscape using a recently released dataset of bed topography (BEDMAP2). We used the existing classification as a basis for first developing a low-resolution description of landscape evolution under the ice sheet before building a more detailed classification of patterns of glacial erosion. Our key finding is that a more widespread distribution of ancient, preserved alpine landscapes may survive beneath the Antarctic ice sheets than has been previously recognized. Furthermore, the findings suggest that landscapes of selective erosion exist further inland than might be expected, and may reflect the presence of thinner, less extensive ice in the past. Much of the selective nature of erosion may be controlled by pre-glacial topography, and especially by the large-scale tectonic structure and fluvial valley network. The hypotheses of landscape evolution presented here can be tested by future surveys of the Antarctic ice sheet bed.


2016 ◽  
Vol 62 (236) ◽  
pp. 1049-1064 ◽  
Author(s):  
JOHN W. GOODGE ◽  
JEFFREY P. SEVERINGHAUS

ABSTRACTA new Rapid Access Ice Drill (RAID) will penetrate the Antarctic ice sheets in order to create borehole observatories and take cores in deep ice, the glacial bed and bedrock below. RAID is a mobile drilling system to make multiple long, narrow boreholes in a single field season in Antarctica. RAID is based on a mineral exploration-type rotary rock-coring system using threaded drill pipe to cut through ice using reverse circulation of a non-freezing fluid for pressure-compensation, maintenance of temperature and removal of ice cuttings. Near the bottom of the ice sheet, a wireline latching assembly will enable rapid coring of ice, the glacial bed and bedrock below. Once complete, boreholes will be kept open with fluid, capped and available for future down-hole measurement of temperature gradient, heat flow, ice chronology and ice deformation. RAID is designed to penetrate up to 3300 m of ice and take cores in <200 hours, allowing completion of a borehole and coring in ~10 d at each site. Together, the rapid drilling capability and mobility of the system, along with ice-penetrating imaging methods, will provide a unique 3-D picture of interior and subglacial features of the Antarctic ice sheets.


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