Chinese Journal of Polar Research

Chinese Journal of Polar Research ›› 2024, Vol. 36 ›› Issue (4): 623-639.DOI: 10.13679/j.jdyj.20230003

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Morphological characteristics and influencing factors of iceberg furrows on the western Amundsen Sea continental shelf margin

ZHAO Ning1,2,3, GAO Jinyao2,3,4, MA Pengyun1,2,3, HAN Xibin2,3, SUN Xi2,3, YANG Fanlin1, GE Qian2,3, DONG Chao4, LU Xiaoming2,3, YANG Chunguo2,3   

  1. 1College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266590, China;
    2Key Laboratory of Submarine Geosciences, Ministry of Nature Resources, Hangzhou 310012, China;
    3Second Institute of Oceanography, Ministry of Nature Resources, Hangzhou 310012, China;
    4Key Laboratory of Marine Environmental Exploration Technology and Application, Ministry of Natural Resources, 
    Guangzhou 510300, China
  • Received:2023-02-20 Revised:2023-04-14 Online:2024-12-31 Published:2025-01-15
  • Contact: Xi-Bin HAN

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Abstract: Iceberg furrow is a typical iceberg erosion landform, and its morphological characteristics and influencing factors are related to iceberg morphology, keel depth and drift direction, which is helpful to understand the history and dynamics of ice shelf edge cracking. In this paper, a large number of iceberg furrows were discovered by interpreting the high-precision multi-beam water depth topography of the western Amundsen Sea shelf in Antarctica. The shape and distribution characteristics of iceberg furrows and corrugation ridge were analyzed by using the V-index model. The strike and length of iceberg furrows and the ridge height and ridge spacing of the corrugation ridge in the ridge were calculated, and the influencing factors were discussed. The width-depth ratio of iceberg furrows, the size of V-index and the morphological characteristics of the cross section can well indicate the size and shape of the iceberg keel that formed the furrows, indicating that the main strike of all iceberg furrows in the study area is NEE—SWW, and the main strike of the intact upper furrows is NE, which is mainly related to the coastal current flowing to the outer edge of the shelf. Part of the longer furrow strike is NW, which is mainly related to westward coastal current, easterly downwind or Antarctic continental slope current. The average V-index of iceberg furrow was 0.132 and the median was 0.121, and the average width-depth ratio was 32.33 and the median was 27.37. The smaller width-to-depth ratio and V-index indicate that the formation of iceberg furrows is mainly associated with smaller icebergs with deeper, sharper keels. The corrugation ridges are distributed in the interior or edge of furrows, the ridge height ranges from 0.1 to 5.7 m, the average ridge height is 2.0 m, and the ridge spacing is 10 to 288 m. The analysis shows that the formation is mainly caused by the accumulation of sediments on the back edge of icebergs under the vertical action of tides.

Key words: iceberg furrow, iceberg keel, morphological characteristics and influencing factors, Amundsen Sea