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冰川冻土 ›› 2023, Vol. 45 ›› Issue (2): 456-467.doi: 10.7522/j.issn.1000-0240.2023.0035

• 冰冻圈与全球变化 • 上一篇    下一篇

阿拉斯加特纳冰川近期跃动特征分析

马致远1(), 蒋宗立1(), 刘时银2,3, 上官冬辉3, 王振峰1, 张勇1, 魏俊锋1   

  1. 1.湖南科技大学 地球科学与空间信息工程学院, 湖南 湘潭 411201
    2.云南大学 国际河流与生态安全研究院, 云南 昆明 650500
    3.中国科学院 西北生态环境资源研究院 冰冻圈科学国家重点实验室, 甘肃 兰州 730000
  • 收稿日期:2022-12-30 修回日期:2023-04-13 出版日期:2023-04-25 发布日期:2023-08-28
  • 通讯作者: 蒋宗立 E-mail:hnustmzy@163.com;jiangzongli@hnust.edu.cn
  • 作者简介:马致远,硕士研究生,主要从事冰川变化遥感研究. E-mail: hnustmzy@163.com
  • 基金资助:
    湖南省自然科学基金项目(2022JJ30243);国家自然科学基金项目(41471067)

Characteristics of recent surging of Turner Glacier, Alaska

Zhiyuan MA1(), Zongli JIANG1(), Shiyin LIU2,3, Donghui SHANGGUAN3, Zhenfeng WANG1, Yong ZHANG1, Junfeng WEI1   

  1. 1.School of Earth Sciences and Spatial Information Engineering,Hunan University of Science and Technology,Xiangtan 411201,Hunan,China
    2.Institute of International Rivers and Eco-security,Yunnan University,Kunming 650500,China
    3.State Key Laboratory of Cryospheric Science,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China
  • Received:2022-12-30 Revised:2023-04-13 Online:2023-04-25 Published:2023-08-28
  • Contact: Zongli JIANG E-mail:hnustmzy@163.com;jiangzongli@hnust.edu.cn

摘要:

特纳冰川是阿拉斯加地区的短周期跃动型冰川。针对该冰川的研究多基于光学遥感图像进行,未能获得详细的运动速度和表面高程变化信息,其跃动过程及控制机制仍需深入研究。本文使用Sentinel-1A、TerraSAR-X/TanDEM-X、ICESat-2、Landsat等多源遥感数据,获取特纳冰川2019—2021年跃动期间表面流速、表面高程以及冰川末端位置变化。结果表明:特纳冰川自2018年12月—2019年7月发生微跃动,于2020年2月进入快速运动期,表面流速大幅增加,期间峰值流速达(18.85±0.05) m·d-1;2021年8月,冰川流速急剧下降后趋于平静。跃动期间,冰川积蓄区物质向下迁移,最大减薄约(105.18±4.18) m;下游接收区隆起,最大增厚约(60.25±4.18) m,末端向前推进(222±30) m。较高的峰值流速、较短的活跃期以及季节性流速变化证明特纳冰川可能受冰下水文机制控制。结合现有数据及文献,特纳冰川距上次跃动时间间隔约为6年。北流线距末端约27 km的类凹槽底部地形结构以及冰瀑布(LN≈23 km)使得冰川积蓄区物质在跃动后可快速积累;冰川末端接海很可能使得冰川末端发生崩解或底部消融加快,从而导致接收区加速减薄。推测降水丰富引起的较高物质积累率以及底部地形结构导致特纳冰川积蓄区快速恢复、接收区迅速减薄,从而导致其跃动周期极短。

关键词: 冰川跃动, 冰川表面流速, 偏移追踪, 冰川表面高程, 特纳冰川

Abstract:

There are many surge-type glaciers in Alaska, and Turner Glacier is of great interest because of its extremely short recurrence interval. Previous studies on this glacier have mostly used optical remote sensing images, which failed to obtain detailed information on the movement velocity and surface elevation changes, and its surging process and control mechanism still need to be studied in depth. In this paper, we use Sentinel-1A, TerraSAR-X/TanDEM-X, ICESat-2 and Landsat remote sensing data to obtain the surface flow velocity, surface elevation and changes of terminal position of Turner Glacier during its recent surge from 2019 to 2021. The results show that Turner Glacier underwent a mini-surge from December 2018 to July 2019, which triggered a rapid movement of the glacier in February 2020 with a peak flow velocity of (18.85±0.05) m·d-1; in August 2021, the glacier flow velocity dropped sharply and then calmed down. During this surge, the material in the accumulation zone of the glacier migrates downward with a maximum thinning of (105.18±4.18) m; the downstream receiving zone rises with a maximum thickening of (60.25±4.18) m, and the end advances (222±30) m. The higher peak flow velocity, shorter active period, and seasonal flow velocity variation demonstrate that Turner Glacier may be controlled by subglacial hydrological mechanisms. Combining the available data and literature, the interval between the last surge is found to be about 6 years. The notch-like bottom topography of the north flow line about 27 km (LN≈27 km) from the terminal and the icefall (LN≈23 km) allow for a rapid accumulation of material in the accumulation zone after the surge. The joining of the sea at the glacier terminal is likely to allow for terminal calving or accelerated ablation of the bottom, leading to accelerated thinning of the receiving area. The high accumulation rate due to abundant precipitation and the bottom topographic structure lead to rapid recovery of the accumulation zone and rapid thinning of the receiving zone of Turner Glacier, resulting in an exceptionally short recurrence interval.

Key words: glacier surging, glacier surface velocity, offset tracking, glacier surface elevation, Turner Glacier

中图分类号: 

  • P343.6