Developing novel remote sensing techniques to quantity glacier change in the Pan-Arctic

Abstract

Since the last century, glaciers have been retreating due to climate change, especially in the Arctic, which is causing the sea level to rise, has the potential to change global weather and climate patterns. Therefore, it is important to understand climate change impacts on glaciers and to develop new automated approaches that can accurately quantify glacier area changes. In this study, we developed a new Object-based image analysis approach in Google Earth Engine, utilizing Landsat satellite imagery and mapped a total of 2,203 (≈32,894 km2) glaciers in four regions in the Arctic and high latitudes: Novaya Zemlya, Russia, Baffin Island, Canada, Disko Island, Greenland and Kenai, Alaska at three different time periods; 1985-89, 2000-02, and 2019-21.

The results showed a clear reduction in the total glacier area in each region. 480 glaciers in Novaya Zemlya that cover an area of 22,990±301 km2 experienced a 1,319±419 km2 (5.7%) decline in total glacier area. 523 glaciers on Baffin Island covering 7,211±158 km2 lost a total area of 452±227 Km2 (6.6%). 748 glaciers on Disko Island covering 1,929±127 km2 lost 457±168 km2 (23.6%), and 452 glaciers in Kenai covering 764±60 km2 lost 196±84 km2 (25.7%). Seventy-three glaciers have completely retreated including sixty-nine on Disko Island, three on Novaya Zemlya, and one in Kenai. The results also show that glaciers area loss was greater in 2000-02 to 2019-21, compared to 1985-89 to 2000-02 in all four regions.

The accuracy of this method was evaluated by comparing manually corrected outlines, resulting in an overall accuracy estimate between 93% and 98% with the reference data based on random sampling approach. This demonstrates that our methodology in GEE is a powerful and robust tool for glacier mapping that reduces time required for manual correction and has the potential to be applied to other glacierised regions.

Date of Award	Jun 2023
Original language	English
Sponsors	Vice Chancellor's Research Scholarship (VCRS)
Supervisor	Dermot Kerr (Supervisor), Robert McNabb (Supervisor), Sonya Coleman (Supervisor), Paul Dunlop (Supervisor) & Riko Noormets (Supervisor)