https://repository.kopri.re.kr/handle/201206/16734 2026-07-13T21:18:45Z https://repository.kopri.re.kr/handle/201206/16826 Title: A seismic analysis of sub glacial lake D2(Subglacial Lake Cheongsuk) beneath David Glacier, Antarctica Authors: Ju, Hyeon Tae; Kang, Seung-Goo; Choi, Yeonjin; Pyun Sukjoon; Lee, Min Je; Kwak, Hoje; Kim, KwanSoo; Kim, Yeadong; Lee, Jong Ik Abstract: Subglacial lakes beneath Antarctic glaciers are pivotal in advancing our understanding of cryosphere dynamics, basal hydrology, and microbial ecosystems. We investigate the internal structure and physical properties of Subglacial Lake D2 (SLD2), which is located beneath David Glacier in East Antarctica, using seismic data acquired during the 2021/22 austral summer. The dataset underwent a comprehensive processing workflow, including noise attenuation, velocity analysis, and prestack time migration. The migrated seismic sections revealed distinct reverse-polarity reflections at the glacier-lake interface; however, reflections from the lake-bed sediment interface were ambiguous, leading to interpretational uncertainty about the presence of a sediment layer. To resolve this interpretational uncertainty, two alternative structural models were established: Model 1 (no sediment) and Model 2 (with a sediment layer). Synthetic seismograms generated by wave-propagation modeling were compared with field data to validate the subglacial lake structure. The results confirmed the water column thickness to be approximately 82 m (Model 1) or approximately 10 m (Model 2), and possible structural scenarios for the subglacial lake were presented. Additionally, discontinuous reflections detected in seismic sections transverse to the ice flow were interpreted as scour-like feature surfaces formed by ice movement. This study identified the basal structure beneath the subglacial lake, which had been challenging to identify with conventional radar surveys, through seismic surveying. In addition, ambiguous signals in the field seismic data were mitigated via quantitative comparison with synthetic data, thereby facilitating interpretation of the underlying structure. Collectively, these findings enhance our understanding of subglacial lake environments and inform the selection of future drilling sites for in situ sampling. 2026-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/16821 Title: Geophysical and Remote Sensing Monitoring of a Snow Patch System in Barton Peninsula Shows Impacts of Warming on Low-Altitude Permafrost Authors: Kim, KwanSoo; Hong, Soon Gyu; Ju, Hyeon Tae; Lee, Joohan; Senkaya Mustafa; Correia Antonio; Kim Won-Ki Abstract: Antarctica, a critical regulator of global climate, faces threats to its permafrost and ecosystems from recent warming. However, a quantitative understanding of subsurface responses remains limited, hindering accurate environmental modeling. This gap hinders accurate modeling of future environmental changes. This study investigates the influence of rising air temperatures on thaw depth and permafrost characteristics by quantifying the links between surface environmental changes and subsurface responses. From 2018 to 2024, we integrated meteorological observations, drone and satellite remote sensing, and geophysical surveys-electrical resistivity tomography (ERT) and ground-penetrating radar (GPR)-to assess atmosphere, surface, and subsurface changes. Our results revealed an overall warming trend during the study period, with the average annual air temperature rising by approximately 1 degrees C and the thaw season extending by up to 50 days. Earlier snowmelt reduced albedo, increasing soil heat absorption and meltwater infiltration. The thaw depth thickened from 1.1 to 1.5 m (maximum) and from 0.65 to 0.85 m (dry sites). ERT indicated reduced resistivity at similar to 1-m depth, reflecting permafrost ice melt, and localized meltwater pooling at similar to 3-m depth. Normalized difference vegetation index data showed increased vegetation activity. Our study shows that even slight warming can drive linked physical and ecological shifts in Antarctica, with implications for global climate feedbacks. Our quantitative analysis of the increasing late-summer thaw depth provides important data that can contribute to the validation and improvement of regional climate models. 2025-12-01T00:00:00Z