5:15 PM - 6:45 PM
[MIS01-P22] Reduction of glaciation on Novaya Zemlya from 1952 to 2023 according to open space data.
Keywords:Remote sensing, glaciers, climate
Modern glaciation of the Arctic islands plays a dominant role in the nature of these areas and serves as an important natural indicator of climate change. Glaciation of Novaya Zemlya ranks first in the Asian sector of the Arctic in terms of area and volume of ice. It was estimated from a 1952 aerial photograph to be about 23,637 km2. During the entire observation period, the glaciers of Novaya Zemlya were shrinking. V. Koryakin estimated the overall decrease in glaciation on Novaya Zemlya for four periods: 1913-1933 – 38 km2 (0.4%), 1933-1959 – 186 km2 (2.2%), 1959-1973 – 133 km2 (1.4%), 1973-1988 – 67 km2 (0.7%).
The purpose of this study is to use open space images to record the current state of glaciation in Novaya Zemlya, the position of glaciers, and obtain values of ice areas for several observation periods since 1952.
As a baseline, we used the diagram and tables of the USSR Glacier Catalog, compiled based on the results of aerial photography in 1952 (Fig. 1a, 1c). Using images from the Corona 1961 satellite, we were able to clarify the boundaries of smaller glaciers that were not depicted in sufficient detail on this map.
The current state of the glaciers of Novaya Zemlya was obtained from satellite images of Landsat-8 and Sentinel-2 (Fig. 1b, 1d) at the end of the ablation period (August 2023). Mapping of open ice and snow cover was carried out using the spectral classification method, followed by manual adjustment of the ice contour. Manual adjustment was carried out for glacier areas with surface moraine, as well as for snowy glacier edges.
Using the same method, the positions of glacier tongues were recorded for four more dates: 1976 (according to the Corona satellite); 1986 (according to Landsat-5 TM data); 2001 (according to Landsat-7 ETM+ data); 2013 (according to Landsat-8 OLI/TIRS data). Thus, we obtained the contours and values of glacier areas for 1952 (1961), 1976, 1986, 2001, 2013 and 2023.
According to the results of our research, the total area of glaciation on Novaya Zemlya decreased by 9.7% from 23.6 thousand km2 in 1952 to 21.4 thousand km2 in 2023. Moreover, in the southern part of the archipelago, where there are 347 mountain glaciers with an area of 0.5 to 57 km2, there was a reduction of 45.2%. Some of them, as a result of contraction, disintegrated into their component parts, and some completely disappeared.
Based on measurement data, it was found that the intensity of loss of glaciers in the Barents Sea basin is significantly higher than that of glaciers on the eastern side. This may be due to the different morphology of the glaciers on the western and eastern slopes and to the increase in temperature in the northern part of the Barents Sea. As a result of the measurements, an increase in the rate of reduction of glaciation on Novaya Zemlya was recorded by 1.3 times over the past 20 years.
For the outlet glaciers of Novaya Zemlya, the rate of change in the frontal parts is significantly influenced by iceberg runoff. This factor is not directly related to climate, but affects the change in glaciers as a result of interaction with adjacent water areas. Changes in the consumption of ice on icebergs are determined by the depth of sea waters at the fronts of glaciers, the topography of the seabed and shores in places where glaciers emerge, temperature distribution, local currents, tidal regime, etc. A factor that may directly depend on climate change is an increase in the number of days per year , free from sea ice. It is possible to assess the contribution of icebergs to the decrease in the area of glaciers using the interpretation of satellite radar images.
As a result of this research, a geoportal was formed that included satellite images and vector maps of Novaya Zemlya glaciers in 2023, and glaciation maps of 2013, 2001, 1986, 1976, 1961. and diagram 1952
Geoportal address: https://maps.kosmosnimki.ru/api/index.html?permalink=WRTMK&D71F6813F9984A6AAFC486629CCD27BD
Figure 1. Reduction of glaciation on Novaya Zemlya (a, b), Reduction in the area and length of the Vera outlet glacier (c, d)
The purpose of this study is to use open space images to record the current state of glaciation in Novaya Zemlya, the position of glaciers, and obtain values of ice areas for several observation periods since 1952.
As a baseline, we used the diagram and tables of the USSR Glacier Catalog, compiled based on the results of aerial photography in 1952 (Fig. 1a, 1c). Using images from the Corona 1961 satellite, we were able to clarify the boundaries of smaller glaciers that were not depicted in sufficient detail on this map.
The current state of the glaciers of Novaya Zemlya was obtained from satellite images of Landsat-8 and Sentinel-2 (Fig. 1b, 1d) at the end of the ablation period (August 2023). Mapping of open ice and snow cover was carried out using the spectral classification method, followed by manual adjustment of the ice contour. Manual adjustment was carried out for glacier areas with surface moraine, as well as for snowy glacier edges.
Using the same method, the positions of glacier tongues were recorded for four more dates: 1976 (according to the Corona satellite); 1986 (according to Landsat-5 TM data); 2001 (according to Landsat-7 ETM+ data); 2013 (according to Landsat-8 OLI/TIRS data). Thus, we obtained the contours and values of glacier areas for 1952 (1961), 1976, 1986, 2001, 2013 and 2023.
According to the results of our research, the total area of glaciation on Novaya Zemlya decreased by 9.7% from 23.6 thousand km2 in 1952 to 21.4 thousand km2 in 2023. Moreover, in the southern part of the archipelago, where there are 347 mountain glaciers with an area of 0.5 to 57 km2, there was a reduction of 45.2%. Some of them, as a result of contraction, disintegrated into their component parts, and some completely disappeared.
Based on measurement data, it was found that the intensity of loss of glaciers in the Barents Sea basin is significantly higher than that of glaciers on the eastern side. This may be due to the different morphology of the glaciers on the western and eastern slopes and to the increase in temperature in the northern part of the Barents Sea. As a result of the measurements, an increase in the rate of reduction of glaciation on Novaya Zemlya was recorded by 1.3 times over the past 20 years.
For the outlet glaciers of Novaya Zemlya, the rate of change in the frontal parts is significantly influenced by iceberg runoff. This factor is not directly related to climate, but affects the change in glaciers as a result of interaction with adjacent water areas. Changes in the consumption of ice on icebergs are determined by the depth of sea waters at the fronts of glaciers, the topography of the seabed and shores in places where glaciers emerge, temperature distribution, local currents, tidal regime, etc. A factor that may directly depend on climate change is an increase in the number of days per year , free from sea ice. It is possible to assess the contribution of icebergs to the decrease in the area of glaciers using the interpretation of satellite radar images.
As a result of this research, a geoportal was formed that included satellite images and vector maps of Novaya Zemlya glaciers in 2023, and glaciation maps of 2013, 2001, 1986, 1976, 1961. and diagram 1952
Geoportal address: https://maps.kosmosnimki.ru/api/index.html?permalink=WRTMK&D71F6813F9984A6AAFC486629CCD27BD
Figure 1. Reduction of glaciation on Novaya Zemlya (a, b), Reduction in the area and length of the Vera outlet glacier (c, d)