論文

査読有り
2016年12月

Thermal structure of proglacial lakes in Patagonia

Journal of geophysical research earth surface
  • Sugiyama Shin
  • ,
  • Minowa Masahiro
  • ,
  • Sakakibara Daiki
  • ,
  • Skvarca Pedro
  • ,
  • Sawagaki Takanobu
  • ,
  • Ohashi Yoshihiko
  • ,
  • Naito Nozomu
  • ,
  • Chikita Kazuhisa

121
12
開始ページ
2270
終了ページ
2286
記述言語
英語
掲載種別
DOI
10.1002/2016JF004084
出版者・発行元
American Geophysical Union

Calving glaciers are rapidly retreating in many regions under the influence of ice-water interactions at the glacier front. In contrast to the numerous researches conducted on fjords in front of tidewater glaciers, very few studies have been reported on lakes in which freshwater calving glaciers terminate. To better understand ice-water interactions at the front of freshwater calving glaciers, we measured lakewater temperature, turbidity, and bathymetry near Glaciar Perito Moreno, Upsala, and Viedma, large calving glaciers of the Southern Patagonia Icefield. The thermal structures of these lakes were significantly different from those reported in glacial fjords. There was no indication of upwelling subglacial meltwater; instead, turbid and cold glacial water discharge filled the region near the lake bottom. This was because water density was controlled by suspended sediment concentrations rather than by water temperature. Near-surface wind-driven circulation reaches a depth of similar to 180 m, forming a relatively warm isothermal layer (mean temperature of similar to 5-6 degrees C at Perito Moreno, similar to 3-4 degrees C at Upsala, and similar to 6-7 degrees C at Viedma), which should convey heat energy to the ice-water interface. However, the deeper part of the glacier front is in contact with stratified cold water, implying a limited amount of melting there. In the lake in front of Glaciar Viedma, the region deeper than 120 m was filled entirely with turbid and very cold water at pressure melting temperature. Our results revealed a previously unexplored thermal structure of proglacial lakes in Patagonia, suggesting its importance in the subaqueous melting of freshwater calving glaciers.

リンク情報
DOI
https://doi.org/10.1002/2016JF004084
CiNii Articles
http://ci.nii.ac.jp/naid/120005981460
URL
http://hdl.handle.net/2115/64883
ID情報
  • DOI : 10.1002/2016JF004084
  • ISSN : 2169-9003
  • CiNii Articles ID : 120005981460

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