Seven-year variation in glacier surface velocity at Narsap Sermia in Southwest Greenland

• Published in: GIScience & Remote Sensing
• Main Authors: Seong-Woo Jung, Sang-Hoon Hong
• Format: Article in Journal/Newspaper
• Language: English
• Published: Taylor & Francis Group 2023
• Subjects: ice velocity; narsap sermia; offset tracking; sar; glacier; time series analysis; Mathematical geography. Cartography; GA1-1776; Environmental sciences; GE1-350; Greenland; Narsap Sermia; Ice Sheet; Tidewater
• Online Access: https://doi.org/10.1080/15481603.2023.2207301; https://doaj.org/article/bef931e5a9d24d61aebb4702f9a60eee

Glacier velocity is a critical factor closely related to ice dynamics of the Greenland ice sheet (GrIS). We present variations of ice velocity using space-based synthetic aperture radar (SAR) observations from July 2013 to September 2020. We focus on a tidewater outlet glacier of Narsap Sermia (NS), located in southwest Greenland, which is experiencing significant ice loss. A time series of high spatiotemporal resolution maps of ice velocity was traced by using an offset tracking approach with seven-year SAR acquisitions to understand glacier dynamics in time. We observed seasonal variations showing a dramatic increase in late spring (May) and early summer (June) followed by a sharp decrease in late summer (September). The seasonal variation was confirmed through Seasonal and Trend decomposition using Loess (STL) analysis. Overall, the NS glacier experienced a gradual speed-up of ice velocities. The ice velocity increased by 0.1–0.3 km/year from 2015 to 2017, then after a temporary decrease in 2018, the velocity moved faster by 0.9 km/year in 2020. The speed of glacier movement accelerated as it approached the tidal terminus of the glacier, showing approximately 6.0 km/year in 2020. The ice speed in 2020 increased by 0.9 km/year at the terminus region compared with 2014. We also discuss the relationship between the glacier velocity and temperature data such as air, land surface, and sea surface temperatures.