scholarly journals Glacier Geometry Changes in the Western Shore of Admiralty Bay, King George Island over the Last Decades

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1532
Author(s):  
Mariusz Pasik ◽  
Krzysztof Bakuła ◽  
Sebastian Różycki ◽  
Wojciech Ostrowski ◽  
Maria Elżbieta Kowalska ◽  
...  

This paper presents changes in the range and thickness of glaciers in Antarctic Specially Protected Area (ASPA) No. 128 on King George Island in the period 1956–2015. The research indicates an intensification of the glacial retreat process over the last two decades, with the rate depending on the type of glacier front. In the period 2001–2015, the average recession rate of the ice cliffs of the Ecology Glacier and the northern part of the Baranowski Glacier was estimated to be approximately 15–25 m a−1 and 10–20 m a−1, respectively. Fronts of Sphinx Glacier and the southern part of the Baranowski Glacier, characterized by a gentle descent onto land, show a significantly lower rate of retreat (up to 5–10 m a−1 1). From 2001 to 2013, the glacier thickness in these areas decreased at an average rate of 1.7–2.5 m a−1 for the Ecology Glacier and the northern part of the Baranowski Glacier and 0.8–2.5 m a−1 for the southern part of the Baranowski Glacier and Sphinx Glacier. The presented deglaciation processes are related to changes of mass balance caused by the rapid temperature increase (1.0 °C since 1948). The work also contains considerations related to the important role of the longitudinal slope of the glacier surface in the connection of the glacier thickness changes and the front recession.

Author(s):  
Wilmer Sánchez ◽  
Carl Schmitt ◽  
Alexzander Santiago ◽  
Gerles Medina

The role of Black Carbon (BC) as a contributor to glacial retreat is of particular interest to the scientific community and decision makers, due to its impact on snow albedo and glacier melt. In this study, a thermal-optical instrument (LAHM) was used to measure effective Black Carbon (eBC) in a series of surface snow samples collected from the Vallunaraju glacier, Cordillera Blanca, between April 2019 and May 2020. The time series obtained indicates a marked seasonal variability of eBC with maximum concentrations during the dry season and dramatic decrease during the wet season. The concentrations detected ranged between a minimum of 3.73 ng/g and 4.23 ng/g during the wet season and a maximum of 214.13 ng/g and 181.60 ng/g during the dry season, in the accumulation and ablation zone. Using SNICAR model, the reduction of albedo was estimated at 6.36% and 6.60% during the dry season and 0.68% and 0.95% during the wet season, which represents an average radiative forcing of 4.52 ± 1.84 W/m2 and 4.69 ± 1.59 W/m2 in the accumulation zone, and 0.49 ± 0.27 W/m2 and 0.68 ± 0.43 W/m2 in the ablation zone. The melting of snow due to the eBC translates into 80.18 ± 37.30 kg/m2 and 83.16 ± 32.75 kg/m2 during the dry season, and 7.91 ± 4.29 kg/m2 and 10.85 ± 6.62 kg/m2 during the wet season, in the accumulation and ablation zones, respectively. Finally, the HYSPLIT trajectory assessment shows that aerosols predominate in the Amazon rainforest, especially when forest fires are most abundant according to VIIRS images.


2001 ◽  
Vol 80 (3-4) ◽  
pp. 209-227 ◽  
Author(s):  
M. Onida ◽  
F. Galadini ◽  
F. Forcella

AbstractPaleoseismological techniques have been used to investigate gravitational deformations at the Mortirolo Pass (Valtellina region, central Alps), in order to improve the knowledge on the activation mechanisms and the evolution of deep-seated gravitational slope movements. The deformation has been responsible for mass sliding towards the Valtellina depression through the activation of several-hundred-metre-long shear planes. Minor shear planes dipping towards the mountain played the role of antithetic structures. Four trenches were excavated across scarps representing the surficial expression of shear planes affecting the bedrock and Late Pleistocene-Holocene deposits. The excavations enabled to investigate the stratigraphy of Quaternary deposits and the geometry and kinematics of the shear planes affecting them. Radiocarbon analyses on organic material contained in sediments and paleosols enabled to define a succession of displacement events which occurred during the Late Pleistocene-Holocene. Collected data indicate the persistence of the activity until recent times (last movement related to 1810-1540 cal. BP). A sudden movement has been detected along one of the main shear surfaces (dipping towards the valley) with a vertical displacement of several metres. In contrast, numerous displacements (with lower vertical offset) have been detected along the antithetic shear planes. Different hypotheses have been proposed in the past to define the origin of huge gravitational movements (glacial retreat, uplift of the Alpine chain, fault activity). However, the Late Pleistocene cycles of glacial loading and unloading on the mountain slopes seem to be the most probable factors causing deep-seated gravitational movements in the investigated region. A recent dramatic landslide in an area adjacent to the investigated one (Mt. Zandila-Valpola) testifies to the paroxistic evolution of the large scale gravitational deformations. The densely inhabited Valtellina region is affected by a large number of gravitational structures similar to those of the Mortirolo area. In consideration of the possible effects of the paroxistic activation of these structures, detailed studies on the chronology and kinematics of the deformations through the application of paleoseismological techniques should therefore be encouraged.


2014 ◽  
Vol 176 ◽  
pp. 144-152 ◽  
Author(s):  
William S. Beatty ◽  
Dylan C. Kesler ◽  
Elisabeth B. Webb ◽  
Andrew H. Raedeke ◽  
Luke W. Naylor ◽  
...  

2009 ◽  
Vol 44 (8) ◽  
pp. 891-895 ◽  
Author(s):  
Grzegorz Gryziak

This work aimed to investigate the ratio of colonization by terrestrial mites on ice-free areas created by the ongoing climate-induced melting of Antarctic glaciers. Glacier retreat opens new ice-free areas for the colonization by vegetation and animals. The study was undertaken on the Antarctic Specially Protected Area no. 128 (West Coast of the Admiralty Bay, King George Island, South Shetlands Islands). Transects marked between the Ecology, Baranowski and Windy Glaciers, and a sea shore were used to collect soil samples. Oribatid mites were found only on near-shore areas, on patches of vegetation of more than 30 years of age. The colonization by mite communities is strongly determined by the presence of plants.


2020 ◽  
Vol 202 ◽  
pp. 06038
Author(s):  
Devita Faradina ◽  
Maryono Maryono ◽  
Budi Warsito

The waste bank is an alternative waste management in Indonesia. The waste Bank in Gunung Kidul Regency, Yogyakarta is one of the waste banks that has been established and is active until now. The method used to determine the generation and composition of waste is SNI 19-3964-1994. In addition, research data are obtained by observing and interviewing directly in the field, then analyzed by quantitative descriptive. The results showed the average rate of waste generation in Gunung Kidul Regency was 0.48 kg / person / day. The highest composition of waste in Gunung Kidul Regency is organic waste, which is 77.61%, while non-organic waste is 22.39%. At present, the Waste Bank in Gunung Kidul Regency is able to reduce waste by 0.86% with a total of 6,423 m3 / year reduced waste. The benefits of the existence of a waste bank, among others, are in the field of waste management, in terms of economic and social aspects. The potential for waste recycling is 17.49% from 22.39% of the total non-organic waste.


2017 ◽  
Vol 183 ◽  
pp. 181-193 ◽  
Author(s):  
Seyedeh Fatemeh Hosseini ◽  
Mohammad Reza Talaie ◽  
Seyedfoad Aghamiri ◽  
Mohammad Hasan Khademi ◽  
Mohsen Gholami ◽  
...  

1984 ◽  
Vol 30 (105) ◽  
pp. 180-187 ◽  
Author(s):  
Roger Leb. Hooke

AbstractRecent theoretical studies of glacier hydrology have assumed that subglacial conduits are completely filled with water under steady-state conditions. This, however, is not necessarily the case. Where discharges are larger than a few tens of liters per second and the down-glacier slope of the bed is more than a few degrees, the potential energy released by water descending this slope may be capable of melting the walls of a subglacial conduit many times faster than the conduit can close by plastic flow of the ice. As a result, the pressure in such tunnels may normally be atmospheric, or possibly even at the triple-point pressure if there is no open connection to the glacier surface. Simple calculations suggest that such pressures in subglacial conduits may be more common than heretofore anticipated.The positions of such “open” conduits may be unstable to small perturbations in discharge or ice velocity. This is because the mechanical energy available in excess of that needed to balance closure can instead offset the general flow of the ice. Conduits can thus trend diagonally across the direction of ice flow. If an increase in the angle which such a conduit makes with the ice flow direction also results in an increase in slope of the conduit, more mechanical energy will become available, resulting in a positive feedback process.Subglacial channels at atmospheric pressure may influence the origin and morphology of certain glacial landforms, such as eskers and “plastically-molded” features.


2015 ◽  
Vol 370 (1681) ◽  
pp. 20140283 ◽  
Author(s):  
Ian D. Craigie ◽  
Megan D. Barnes ◽  
Jonas Geldmann ◽  
Stephen Woodley

Globally, protected areas are the most commonly used tools to halt biodiversity loss. Yet, some are failing to adequately conserve the biodiversity they contain. There is an urgent need for knowledge on how to make them function more effectively. Impact evaluation methods provide a set of tools that could yield this knowledge. However, rigorous outcome-focused impact evaluation is not yet used as extensively as it could be in protected area management. We examine the role of international protected area funding agencies in facilitating the use of impact evaluation. These agencies are influential stakeholders as they allocate hundreds of millions of dollars annually to support protected areas, creating a unique opportunity to shape how the conservation funds are spent globally. We identify key barriers to the use of impact evaluation, detail how large funders are uniquely placed to overcome many of these, and highlight the potential benefits if impact evaluation is used more extensively.


2009 ◽  
Vol 50 (50) ◽  
pp. 16-24 ◽  
Author(s):  
Francesca Pellicciotti ◽  
Marco Carenzo ◽  
Jakob Helbing ◽  
Stefan Rimkus ◽  
Paolo Burlando

AbstractWe discuss the inclusion of the subsurface heat-conduction flux into the calculation of the energy balance and ablation at the glacier–atmosphere interface. Data from automatic weather stations are used to force an energy-balance model at several locations on alpine glaciers and at one site in the dry Andes of central Chile. The heat-conduction flux is computed using a two-layer scheme, assuming that 36% of the net shortwave radiation is absorbed by the surface layer and that the rest penetrates into the snowpack. We compare simulations conducted with and without subsurface heat flux. Results show that assuming a surface temperature of zero degrees leads to a larger overestimation of melt at the sites in the accumulation area (10.4–13.3%) than in the ablation area (0.5–2.8%), due to lower air temperatures and the presence of snow. The difference between simulations with and without heat conduction is also high at the beginning and end of the ablation season (up to 29% for the first 15 days of the season), when air temperatures are lower and snow covers the glacier surface, while they are of little importance during periods of sustained melt at all the locations investigated.


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