Japan Geoscience Union Meeting 2023

Presentation information

[J] Online Poster

M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS08] Global climate change driven by the Southern Ocean and the Antarctic Ice Sheet

Fri. May 26, 2023 3:30 PM - 5:00 PM Online Poster Zoom Room (10) (Online Poster)

convener:Kazuya Kusahara(Japan Agency for Marine-Earth Science and Technology), Masahiro Minowa(Institute of Low Temperature Science, Hokkaido University), Yoshifumi Nogi(National Institute of Polar Research), Osamu Seki(Institute of Low Temperature Science, Hokkaido University)

On-site poster schedule(2023/5/26 17:15-18:45)

3:30 PM - 5:00 PM

[MIS08-P05] Estimation of velocity upstream of the grounding line of Shirase Glacier using Sentinel-1 data

*Shotaro Ohkawa1, Koichiro Doi2,1, Yuichi Aoyama2,1 (1.The Graduate University for Advanced Studies, SOKENDAI, 2.National Institute of Polar Research)

Keywords:Shirase Glacier, Sentinel-1, Flow velocity

Ice mass discharge by glaciers is one of the critical parameters in estimating the mass balance of the Antarctic ice sheet. Observation of glacier flow rates at the grounding line (GL) is necessary to estimate the ice discharge from the ice sheet and perform a precise mass balance analysis.

The target area for this study is Shirase Glacier, located in East Antarctica. Shirase Glacier is known to be one of the fastest flowing glaciers in Antarctica. We obtained radar images acquired from July 2018 to December 2022 by the Synthetic Aperture Radar (SAR) onboard the Sentinel-1A satellite, which has a repeat cycle of 12 days. The offset tracking technique was applied to estimate the flow velocity of the Shirase Glacier.

The results of offset tracking indicated that the flow velocity of the Shirase Glacier at the grounding line (GL) decreased from 2020 to 2022 as well as downstream of the GL (Ohkawa et al., 2022). The preliminary analysis suggests that the flow velocity upstream of the GL has also experienced a decrease.

In order to gain a greater understanding of the relationship between the flow velocity at GL and the upstream in the future, we intend to analyze any trends and discern whether there are any seasonal variations in the upstream flow velocity. Furthermore, we would like to determine whether it is concurrent or out of phase with the decrease in downstream velocity.

Acknowledgment
This study was partially supported by JSPS KAKENHI Grant No. 17H06321.