scholarly journals Formation of a large ice depression on Dålk Glacier (Larsemann Hills, East Antarctica) caused by the rapid drainage of an englacial cavity

2021 ◽  
pp. 1-16
Author(s):  
Alina Boronina ◽  
Sergey Popov ◽  
Galina Pryakhina ◽  
Antonina Chetverova ◽  
Ekaterina Ryzhova ◽  
...  

Abstract In the afternoon of 30 January 2017, a catastrophic outburst flood occurred in the Larsemann Hills (Princess Elizabeth Land, East Antarctica). The rapid drainage of both a thin supraglacial layer of water (near Boulder Lake) and Lake Ledyanoe into the englacial Lake Dålk provoked its overfill and outburst. As a result, a depression of 183 m × 220 m was formed in the place where Lake Dålk was located. This study summarises and clarifies the current state of knowledge on the flood that occurred in 2017. We present a phenomenological model of depression formation. We specify the reasons for the outburst of the system of lakes Boulder, Ledyanoe and Dålk. In addition, we carry out mathematical modelling of the outburst of each of the three lakes and estimate the flood severity. Outburst hydrographs, channel diameters, volume and duration of floods were calculated. Particular simulation results were validated with field data. In conclusion, we give an overview of the new outburst cycle of the lake system, which began in 2020 with the drainage of the lakes Boulder and Ledyanoe, and the new formation of Lake Dålk. Further research is required to improve our understanding of the lake system responses to changing external factors.

Author(s):  
Steven K. Spreitzer ◽  
Jesse B. Walters ◽  
Alicia Cruz‐Uribe ◽  
Michael L. Williams ◽  
Martin G. Yates ◽  
...  

Polar Record ◽  
1996 ◽  
Vol 32 (180) ◽  
pp. 43-50 ◽  
Author(s):  
Z. Wang ◽  
F.I. Norman ◽  
J.S. Burgess ◽  
S.J. Ward ◽  
A.P. Spate ◽  
...  

AbstractBreeding activity of pairs of south polar skuas (Catharacta maccormicki) in the eastern Larsemann Hills, Princess Elizabeth Land, East Antarctica, was recorded in five of six austral summers between 1988 and 1994. More detailed observations of breeding success were made in the 1989/90 and 1993/94 summers. Although relatively few skuas nest in the study area, data suggest that there was inter-annual variation in numbers and locations of territories and chicks fledged. This variation is discussed in relation to increased human activities in the area (development of a summer base and more permanent stations) and to an enhanced access to human-derived foods. It is concluded that there has been some human impact on this species in the Larsemann Hills.


1999 ◽  
Vol 2 (4) ◽  
pp. 641-642
Author(s):  
Y. Zhao ◽  
X. Liu ◽  
B. Song ◽  
P. Liu

2021 ◽  
Vol 193 (12) ◽  
Author(s):  
Rupali Pal ◽  
Aditi C. Patra ◽  
A. K. Bakshi ◽  
Bhushan Dhabekar ◽  
Priyanka J. Reddy ◽  
...  

Radiocarbon ◽  
2016 ◽  
Vol 59 (2) ◽  
pp. 489-503 ◽  
Author(s):  
E Zazovskaya ◽  
N Mergelov ◽  
V Shishkov ◽  
A Dolgikh ◽  
V Miamin ◽  
...  

AbstractThis article discusses radiocarbon dating results for soils and soil-like systems in the East Antarctic oases, including Schirmacher, Thala Hills, and Larsemann Hills. The organic matter of endolithic and hypolithic systems, soils of wind shelters, and soils under moss-algae vegetation were dated along with micro- and macroprofiles. Organic matter pools formed under extreme climatic conditions and originated not from vascular plants but from cryptogamic organisms, and photoautotrophic microbes have been identified within the oases of the East Antarctica. The organic matter of the most of East Antarctic soils is young and cannot reach a steady state because of the high dynamism in the soil cover due to active erosion. The oldest soil organic matter in East Antarctica was found in the soils formed in wind shelters and endolithic soil-like systems under the protection of consolidated rock surfaces. According to our data, the maximal duration for the formation of organic matter profiles within the oases of East Antarctica is ~500 yr, which is similar to the age determined for High Arctic soils in Eurasia. The absence of older soils, comparable with the Holocene deglaciation, can be due to the extreme conditions resulting in occasional catastrophic events that destroyed the soil organic horizons.


2004 ◽  
Vol 50 (7) ◽  
pp. 113-122 ◽  
Author(s):  
C Printemps ◽  
A Baudin ◽  
T Dormoy ◽  
M. Zug ◽  
P.A. Vanrolleghem

Better controlling and optimising the plant's processes has become a priority for WWTP (Wastewater Treatment Plant) managers. The main objective of this project is to develop a simplified mathematical tool able to reproduce and anticipate the behaviour of the Tougas WWTP (Nantes, France). This tool is aimed to be used directly by the managers of the site. The mathematical WWTP model was created using the software WEST®. This paper describes the studied site and the modelling results obtained during the stage of the model calibration and validation. The good simulation results have allowed to show that despite a first very simple description of the WWTP, the model was able to correctly predict the nitrogen composition (ammonia and nitrate) of the effluent and the daily sludge extraction. Then, a second more detailed configuration of the WWTP was implemented. It has allowed to independently study the behaviour of each of four biological trains. Once this first stage will be completely achieved, the remainder of the study will focus on the operational use of a simplified simulator with the purpose of optimising the Tougas WWTP operation.


2020 ◽  
Author(s):  
Elena Shevnina ◽  
Ekaterina Kourzeneva ◽  
Yury Dvornikov ◽  
Irina Fedorova

Abstract. The study gives first estimates of water transport scale for five lakes located in the Larsemann Hills oasis (69º23' S, 76º20' E) in the East Antarctica. We estimated the lake retention time (LRT) as a ratio of the lake volume to the income and outcome terms of a lake water balance equation. The LRT was evaluated for lakes of epiglacial and land-locked types, and it was assumed that these lakes are monomictic with water exchange existing during a warm season only. We used hydrological observations collected in 4 seasonal field campaigns to evaluate the LRT from the outcome and income terms of the water balance equation. For the epiglacial lakes Progress/LH57 and Nella/Scandrett/LH72, the LRT was estimated of 12–13 and 4–5 years, respectively. For the land-locked lakes Stepped/LH68, Sara Tarn/LH71 and Reid/LH70, our results show a big difference in the LRT calculated from the outcome and income components of the water balance equation. The LRT for these lakes vary depending on the methods and errors inherent to them. We suggested to rely on the estimations from the outcome surface runoff since they are based on the hydrological measurements with better quality. Lake Stepped/LH68 exchange water within less then 1.5 years. Lake Sara Tarn/LH71 and Lake Reid/LH70 are the endorheic ponds with the water exchange through mostly evaporation, their LRT was estimated as 21–22 years and from 8–9 years, respectively. To improve the estimates of the LRT, the hydrological observations are needed to monitor the lakes and streams during the warm season with the uniform observational program.


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