2:00 PM - 2:15 PM
[ACC26-02] Glacial lake formation related to glacier shrinkage in the Kyrgyz Range.
Keywords:glacier, glacial lake, GLOF, moraine
The Kyrgyz Range in Central Asia has experienced the formation of many glacial lakes due to recent warming. Monitoring these lakes is crucial because they often lead to floods known as glacial lake outburst floods (GLOF). However, the long-term trends in glacier shrinkage, moraine change, and recent glacial lake formation are not fully understood. To address this, we conducted a study using satellite images from Corona KH-4, Landsat (7, 8, 9, 10), Sentinel-2, and PlanetScope to analyze glacial lake trends in the Kyrgyz Range from 1968 to 2021. DSMs from Corona data in 1968 and ALOS and High Mountain Asia in 2010 were used to extract lake depressions. We also utilized differential interferometric synthetic aperture radar (DInSAR) data from ALOS-2/PALSAR-2 to examine changes in moraines and their relationship to glacial lake formation.
In 1968, there were 417 glacial lakes in the Kyrgyz Range. By around 2000, 305 glacial lakes had disappeared, leaving behind 112 glacial lakes that continued to expand, with some experiencing significant changes in size. Between 2000 and 2021, we identified 543 glacial lakes, of which 79% were newly formed.
The central Kyrgyz Range had the highest number of glacial lakes in both 1968 and 2000-2021. As the total area of glacial lakes expanded, there was an increased frequency of glacial lakes at altitudes above 3500 m. While the glacier area decreased by 30% over the past 50 years, the number of glacial lakes only slightly increased. However, 80% of the current glacial lakes are new and have emerged since around 2000, indicating that glacial lakes are not consistently maintained as glaciers shrink.
Furthermore, the area of glacial lakes has expanded significantly, increasing fivefold from 0.87 km2 in 1968 to 5.21 km2 in 2021. This expansion is believed to be caused not only by glacier shrinkage but also by the development of depressions due to melting ice in moraine complexes and the growth of thermokarst lakes. Additionally, topographical changes in the moraine complex have led to seasonal variations in glacial lake area.
In summary, the dynamics of glacial lakes in the Kyrgyz Range are a result of glacier shrinkage and the melting of ice within moraine complexes. These findings highlight the need for continued monitoring and understanding of glacial lakes in this region.
In 1968, there were 417 glacial lakes in the Kyrgyz Range. By around 2000, 305 glacial lakes had disappeared, leaving behind 112 glacial lakes that continued to expand, with some experiencing significant changes in size. Between 2000 and 2021, we identified 543 glacial lakes, of which 79% were newly formed.
The central Kyrgyz Range had the highest number of glacial lakes in both 1968 and 2000-2021. As the total area of glacial lakes expanded, there was an increased frequency of glacial lakes at altitudes above 3500 m. While the glacier area decreased by 30% over the past 50 years, the number of glacial lakes only slightly increased. However, 80% of the current glacial lakes are new and have emerged since around 2000, indicating that glacial lakes are not consistently maintained as glaciers shrink.
Furthermore, the area of glacial lakes has expanded significantly, increasing fivefold from 0.87 km2 in 1968 to 5.21 km2 in 2021. This expansion is believed to be caused not only by glacier shrinkage but also by the development of depressions due to melting ice in moraine complexes and the growth of thermokarst lakes. Additionally, topographical changes in the moraine complex have led to seasonal variations in glacial lake area.
In summary, the dynamics of glacial lakes in the Kyrgyz Range are a result of glacier shrinkage and the melting of ice within moraine complexes. These findings highlight the need for continued monitoring and understanding of glacial lakes in this region.