Direct measurement of subaqueous melting at the front of calving glaciers

2016 Fiscal Year Final Research Report

• Project/Area Number: 26550001
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Environmental dynamic analysis
• Research Institution: Hokkaido University
• Principal Investigator: Sugiyama Shin 北海道大学, 低温科学研究所, 教授 (20421951)
• Co-Investigator(Renkei-kenkyūsha): SAWAGAKI TAKANOBU 法政大学, 社会学部, 准教授 (70312410) ; YAMAZAKI SHINTARO 北見工業大学, 工学部, 助教 (40584602)
• Research Collaborator: MINOWA MASAHIRO ; SAKAKIBARA DAIKI ; SCHAEFER MARIUS ; SKVARCA PEDRO
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: カービング氷河 / サイドスキャンソナー / 氷河湖 / フィヨルド / パタゴニア / グリーンランド / 環境変動 / 国際研究者交流

Outline of Final Research Achievements

This project aimed to quantify subaqueous melting at the front of calving glaciers by mapping under-water ice geometry using a side-scanning sonar. We operated a sonar (Imagenex Model 872) in proglacial lakes and fjords in Patagonia, Greenland and Antarctica. At the front of Grey Glacier, a freshwater calving glacier in Patagonia, we found the ice front was extending into the lake by 50-100 m under the water surface. Together with water temperature distributions in the lake, our observation implies that ice melting is enhanced near the water surface. Melt rate was not quantified only from the sonar data, but water temperature, turbidity and isotope measurements enabled us to estimate the subaqueous melting rate at the front of Grey Glacier. The results provided new insights into the frontal ablation and evolution of freshwater calving glaciers.

Free Research Field

氷河学、雪氷学