Measuring the state and temporal evolution of glaciers using SAR-derived 3D time series of glacier surface flow

• Main Authors: Samsonov, Sergey, Tiampo, Kristy, Cassotto, Ryan
• Format: Text
• Language: English
• Published: 2020
• Subjects: glacier; glaciers; Alaska
• Online Access: https://doi.org/10.5194/tc-2020-257; https://tc.copernicus.org/preprints/tc-2020-257/

The direction and intensity of glacier surface flow adjust in response to a warming climate, causing sea level rise, seasonal flooding and droughts, changing landscapes and habitats. However, until recently no single technique could consistently measure the evolution of surface flow for an entire glaciated region in three-dimensions with high temporal and spatial resolutions. We have developed such a technique and use it to map, in unprecedented detail, the temporal evolution of five glaciers in southeastern Alaska (Agassiz, Seward, Malaspina, Klutlan and Walsh) during 2016–2020. We observe seasonal and interannual variations and the maximum horizontal and vertical flow velocity in excess of 1000 and 200 m/year, respectfully. We also observe culminating phases of surging at Klutlan and Walsh glaciers and confirm that Agassiz, Seward and Malaspina glaciers continue to adjust to a warming climate. On a broader scale, this technique can be used for reconstructing the response of worldwide glaciers to the warming climate using nearly 30 years of archived SAR data and for near real-time monitoring of these glaciers using rapid revisit SAR data from satellites, such as Sentinel-1 (6 days revisit period) and forthcoming NISAR (12 days revisit period).