Grain Size Distribution of Bedload Transport in a Glaciated Catchment (Baranowski Glacier, King George Island, Western Antarctica)

The relationships among grain size distribution (GSD), water discharge, and GSD parameters are investigated to identify regularities in the evolution of two gravel-bed proglacial troughs: Fosa Creek and Siodło Creek. In addition, the potential application of certain parameters obtained from the GSD analysis for the assessment of the formation stage of both creeks is comprehensively discussed. To achieve these goals, River Bedload Traps (RBTs) were used to collect the bedload, and a sieving method for dry material was applied to obtain the GSDs. Statistical comparisons between both streams showed significant differences in flow velocity; however, the lack of significant differences in bedload transport clearly indicated that meteorological conditions are among the most important factors in the erosive process for this catchment. In particular, the instability of flow conditions during high water discharge resulted in an increase in the proportion of medium and coarse gravels. The poorly sorted fine and very fine gravels observed in Siodło Creek suggest that this trough is more susceptible to erosion and less stabilized than Fosa Creek. The results suggest that GSD analyses can be used to define the stage of development of riverbeds relative to that of other riverbeds in polar regions

Recent Deceleration of the Ice Elevation Change of Ecology Glacier (King George Island, Antarctica)

Glacier change studies in the Antarctic Peninsula region, despite their importance for global sea level rise, are commonly restricted to the investigation of frontal position changes. Here we present a long term (37 years; 1979–2016) study of ice elevation changes of the Ecology Glacier, King George Island ( 62 ∘ 11 ′ S, 58 ∘ 29 ′ W). The glacier covers an area of 5.21 km 2 and is located close to the H. Arctowski Polish Antarctic Station, and therefore has been an object of various multidisciplinary studies with subject ranging from glaciology, meteorology to glacial microbiology. Hence, it is of great interest to assess its current state and put it in a broader context of recent glacial change. In order to achieve that goal, we conducted an analysis of archival cartographic material and combined it with field measurements of proglacial lagoon hydrography and state-of-art geodetic surveying of the glacier surface with terrestrial laser scanning and satellite imagery. Overall mass loss was largest in the beginning of 2000s, and the rate of elevation change substantially decreased between 2012–2016, with little ice front retreat and no significant surface lowering. Ice elevation change rate for the common ablation area over all analyzed periods (1979–2001–2012–2016) has decreased from −1.7 ± 0.4 m/year in 1979–2001 and −1.5 ± 0.5 m/year in 2001–2012 to −0.5 ± 0.6 m/year in 2012–2016. This reduction of ice mass loss is likely related to decreasing summer temperatures in this region of the Antarctic Peninsula

Structure and dynamics of Waksmundzki channel stream bed

The paper presents the structure and dynamics of Waksmundzki channel stream bed. Studies conducted in the channel in 2010, revealed individual elements of education structure and dynamics of the channel and regularity in the distribution and diversity of forms channel dynamics.Formation of the channel of Waksmundzki steam is determined mainly by postglacial sculpture of Waksmundzka Valley, which led to the formation of the basic elements of the structure of the channel. After the retreat of the glacier, the climate and geological structure have contributed to the modification of the structure and dynamics of the bed of the stream. Basic forms in the analyzed channel stream are thresholds founded on blocks of rock. Their presence in the channel is associated with washing the cover of moraine, which lined the entire bottom of the Waksmundzka Valley. In addition to the structure and dynamics of stream channel Waksmundzki occurrence of coarse rubble timber that creates and forms of co-creates and modifies the flow trough plays a significant role.The result carried out a typology of the channel that was to determine the consequences of erosion, transport and accumulation of the channel segments associated with the dominant processes operating in each of them.Structure and dynamics of Waksmundzki stream bed is strongly correlated with the extent of other Tatra river streams located within the glaciated valleys during the Pleistocene. Evidenced by the similarity of the main elements of the channel and its dynamics.Praca przedstawia strukturę i dynamikę koryta Potoku Waksmundzkiego. Badania przeprowadzone w korycie w 2010 roku ukazały wykształcenie poszczególnych elementów struktury i dynamiki koryta oraz prawidłowości w rozmieszczeniu form korytowych i zróżnicowaniu dynamiki koryta.Uformowanie koryta Potoku Waksmundzkiego jest zdeterminowane w głównej mierze rzeźbą polodowcową Doliny Waksmundzkiej, która wpłynęła na wykształcenie podstawowych elementów struktury koryta. Po ustąpieniu lodowca to klimat oraz budowa geologiczna przyczyniły się do modyfikacji struktury i dynamiki koryta potoku. Podstawowymi formami korytowymi w analizowanym korycie potoku są progi rumowiskowe założone na blokach skalnych. Ich obecność w korycie związana jest z przemywaniem pokryw morenowych, którymi wyścielone jest całe dno Doliny Waksmundzkiej. Dodatkowo dla struktury i dynamiki koryta Potoku Waksmundzkiego znaczącą rolę odgrywa występowanie grubego rumoszu drzewnego, który tworzy i współtworzy formy korytowe oraz modyfikuje przepływ. Wynikiem przeprowadzonej typologii koryta było określenie następstwa erozyjnych, transportacyjnych oraz akumulacyjnych odcinków koryta związanych z dominującymi procesami działającymi w każdym z nich.Struktura i dynamika koryta Potoku Waksmundzkiego jest silnie skorelowana z wykształceniem innych koryt potoków tatrzańskich położonych w obrębie zlodowaconych w plejstocenie dolin. Świadczy o tym podobieństwo głównych elementów struktury koryta oraz ich dynamiki

Recession and Ice Surface Elevation Changes of Baranowski Glacier and Its Impact on Proglacial Relief (King George Island, West Antarctica)

Glacial forefields areas are dynamic landscapes, and due to the glacier frontal position changes, they are sensitive to climatic fluctuations. The results of the analysis of aerial photos, satellite imagery, archival maps, and terrestrial laser scanning surveys are presented. These investigations reveal that the ice surface decreased during the period 1989–2001, when almost the entire current forefield was already uncovered. Moreover, it is shown that, since 1969, there has been a relationship between the changes in air temperature and the changes of the annual front position rate of Baranowski Glacier. Specifically, the results demonstrate that during the cooling observed for the Antarctic Peninsula Regions since 2000, there is a deceleration of the recession rate and ice surface elevation changes of Baranowski Glacier. It is also shown that the fluctuation of the areal extent of the glacier as well as ice surface elevation changes are closely associated with proglacial relief. Moreover, it is shown that the difference in the retreat of the northern and southern tongue of the glacier can be explained by the presence of relatively warm water in the shallow bay, which can enhance the melting process of the northern part. In addition, existence of long flutes and crevasse fill ridges on the analyzed forefield of Baranowski Glacier suggest that the former episodes of its surge, which could happen at least in the northern part of the forefield and middle part of the southern forefield of the glacier

Bedload transport in two creeks at the ice-free area of the Baranowski Glacier, King George Island, West Antarctica

This paper presents a unique case study and methodology for measurements of the bedload transport in the two, newly created troughs at the forefield of the Baranowski Glacier: Fosa and Siodło creeks. The weather conditions and the granulometric analysis are presented and discussed briefly. Rating curves for the Fosa and Siodło creeks are presented for the first time for this region. Changes of the bedload transport as well as water discharge and water velocity at both creeks are investigated. The hysteresis for the relationships between rate of bedload transport and water discharges were identified showing that for both creeks for the higher water levels a figure of eight loop may be easily recognized. Moreover, a new method for the calculation of bedload transport rate, based on the weighted arithmetic mean instead of the arithmetic mean, is proposed