BLUE ICE AREAS EXTRACTION USING LANDSAT IMAGES BASED ON GOOGLE EARTH ENGINE

This paper describes an automatic blue ice extent mapping technique in Grove Mountains, East Antarctica, where the key focused area of the Antarctic scientific expedition and many meteorites are distributed. In previous studies, the monitoring of blue ice extent was usually conducted using satellite images with coarse spatial resolution or offline operation, which lowered the description performance of blue ice in detail as well as the efficiency of continent-scale data production. Using Google Earth Engine, we first developed an automated framework that employs Normalized Difference Water Index (NDWI) indices in joint with the Otsu thresholding method to distinguish blue ice areas on Landsat imagery. Taking Grove Mountains as a study case, we further analyzed the annual variability of blue ice extent in the austral summer from 2007 to 2021. The results indicated that the blue ice extent can be automatically detected based on cloud platform and has no significant variability trend in Grove Mountains over the study period fluctuating with an overall average area of 440 similar to 600 km(2). This framework is expected to be used for automated mapping on the whole of Antarctica and other concentrated blue ice areas (e.g., the East Antarctica ice sheet periphery and the Transantarctic Mountains surroundings) in a rapid and efficient manner, which provides guidance on the meteorite recovery and the support of the polar sustainable development goals.