The main aim of the presented work was to assess Landsat 8 satellite imagery for the presence of cloud cover over the terminal zone of the Aavatsmark Glacier (NW Spitsbergen, Svalbard). The work used all downloadable Landsat 8 imagery taken from the start of the mission (early 2013) to the end of 2020 and covering the entire area of interest (AOI). There were a total of 868 satellite images. The degree of visibility of the AOI zone in each image was calculated using Quality Assessment Band image (QA), which is an integral part of the Landsat 8 dataset. The QA data were reclassified, grouped into specific visibility classes and presented on an annual and monthly basis. An analysis of the incidence of usable imagery, i.e. imagery with no more than 5% cloud cover, was also carried out. Of all the available imagery, over the years analysed, only 176 (approx. 20%) contained a fully visible area, while approx. 60% of the images had more than 95% cloud cover. These data were also compared with the results of cloud cover at the nearest weather station in Ny-Ålesund.
This study utilized electrical resistivity imaging (ERI) to investigate subsurface characteristics near Nicolaus Copernicus University Polar Station on the western Spitsbergen-Kaffiøyra Plain, island in the Svalbard archipelago. Surveys along two lines, LN (148 meters) collected in 2022 and 2023 and ST (40 meters) collected in 2023, were conducted to assess resistivity and its correlation with ground temperatures. The LN line revealed a 1 to 2 meters thick resistive unsaturated outwash sediment layer, potentially indicative of permafrost. Comparing LN resistivity result between 2022 and 2023, a 600 Ohm-m decrease in the unsaturated active layer in 2023 was observed, attributed to a 5.8℃ temperature increase, suggesting a link to global warming. ERI along the ST line depicted resistivity reaching its minimum at approximately 1.6 meters, rising to over 200 Ohm-m at 4 meters, and slightly decreasing to around 150 Ohm-m at 7 meters. Temperature measurements from the ST line's monitoring well confirmed permafrost at a depth of 1.6 to 2 meters. Additionally, water content distribution in the ST line was estimated after temperature correction, revealing a groundwater table depth of approximately 1.06 meters, consistent with measurements from the S4 borehole on the ST line. This study provides valuable insights into Arctic subsurface dynamics, emphasizing the sensitivity of resistivity patterns to climate change and offering a comprehensive understanding of permafrost behavior in the region.
This study utilized electrical resistivity imaging (ERI) to investigate subsurface characteristics near Nicolaus Copernicus University Polar Station on the western Spitsbergen-Kaffiøyra Plain island in the Svalbard archipelago. Surveys along two lines, LN (148 m) collected in 2022 and 2023, and ST (40 m) collected in 2023, were conducted to assess resistivity and its correlation with ground temperatures. The LN line revealed a 1- to 2-m-thick resistive unsaturated outwash sediment layer, potentially indicative of permafrost. Comparing the LN resistivity result between 2022 and 2023, a 600 Ohm.m decrease in the unsaturated active layer in 2023 was observed, attributed to a 5.8 °C temperature increase, suggesting a link to global warming. ERI along the ST line depicted resistivity, reaching its minimum at approximately 1.6 m, rising to over 200 Ohm.m at 4 m, and slightly decreasing to around 150 Ohm.m at 7 m. Temperature measurements from the ST line’s monitoring strongly confirmed that the active layer extends to around 1.6 m, with permafrost located at greater depths. Additionally, water content distribution in the ST line was estimated after temperature correction, revealing a groundwater depth of approximately 1.06 m, consistent with measurements from the S4 borehole on the ST line. This study provides valuable insights into Arctic subsurface dynamics, emphasizing the sensitivity of resistivity patterns to climate change and offering a comprehensive understanding of permafrost behavior in the region.
It is estimated that just over a third of all shorelines in the world are located within polar regions, yet only a small percentage of them has been subject to research and monitoring so far. This extremely important component of the environment is constantly being transformed in times of climate change. With the help of remote sensing and automatic processing models, using generally available satellite programmes, it is becoming possible to conduct morphometric analyses, including in a long-term framework. The article presents the results of 40-year monitoring of changes in the shoreline of Northwest Spitsbergen, divided into sub-periods. From thousands of candidate scenes acquired by Landsat 5–8 and Sentinel-2 and processed using semi-automated tools, only 129 images (1.2% of the initial dataset) met the strict inclusion criteria of spatial congruence with AOI zones and comparable acquisition conditions, namely similar sea levels and cloud cover. Five zones, all located on sandy beaches, were selected for the analysis to demonstrate the main directions of changes and transformation of the Arctic coastlines. The zones had a total length of over 37 km and were chosen owing to their potential differences in oceanic qualities (as verified), spatial conditions (location inside and outside Forlandsundet), and geomorphological considerations. The beaches were predominantly stable and accumulative, with the area changing from ˗0.02 ± 0.09 m yr 1 up to 0.96 ± 0.14 m yr 1 (in the long-term perspective, from ~ 1990 until 2024). It must be emphasised that a comparative analysis of satellite images was carried out with a short-term perspective to follow changes in the river mouth and the emergence and transformation of new lakes, spits, and bays. The results for the selected zones were rigorously validated through comparison with high-resolution DEMs and orthomosaics generated from UAV surveys carried out between 2021 and 2023.