近日，英国伯明翰大学Jonathan M. Carey团队研究了浅层同震海底滑坡塑造峡谷头地貌的瞬态证据：来自2016年新西兰凯库拉地震的见解。相关论文发表在2025年9月22日出版的《地质学》杂志上。

反复发生的滑坡对海底峡谷形态、沉积动力学及海啸灾害的影响目前认知有限。

研究组利用2016年新西兰莫氏7.8级凯库拉地震前后获取的高分辨率（2米）多波束水深数据，首次建立了地震诱发海底滑坡的详细清单。大多数滑坡始于峡谷头壁基岩上覆盖的冰后沉积层中，表现为小型（约1950平方米）、浅层离散型滑移（<10米）。尽管规模有限，但上游峡谷区域失稳物质总量达约1120万立方米，单位面积体积损失约为陆地观测值的100倍，导致头壁后退达210米，并抹除了小型沟谷系统。

这些浅层滑移转化为浊流，为峡谷深部的9.35亿立方米重力流贡献了物质。经校正的数字高程模型（DEM）差分显示，海底滑坡体积比震后预估大1.5-3倍。凯库拉峡谷头壁浅层滑坡所动员的沉积物，为改进沉积物重力流和海底滑坡灾害模型提供了重要启示。尽管沉积物体积巨大，但未引发海啸，这可能是因为滑坡以大量小型离散式滑移形式发生。这些发现表明，在活动大陆边缘环境下，滑坡驱动型海啸灾害风险可能低于预期。

附：英文原文

Title: Transient evidence of shallow coseismic submarine landslides shaping canyon head geomorphology: Insights from the 2016 Kaikōura earthquake, New Zealand

Author: Laura Gnesko, Timothy Stahl, Joshu J. Mountjoy, Jonathan M. Carey

Issue&Volume: 2025-09-22

Abstract: The impact of recurrent landslides on submarine canyon morphology, sediment dynamics, and tsunami hazard is poorly understood. This study presents the first detailed inventory of earthquake-induced submarine landslides, using high-resolution (2 m) pre- and postevent multibeam bathymetry of the upper Kaikōura Canyon, New Zealand, following the Mw 7.8, 2016 Kaikōura earthquake. Most failures initiated as small (～1950 m2), shallow disaggregating slides (<10 m) in postglacial sediments draped over bedrock at the canyon headwall. Despite their size, ～11.2 Mm3 of material failed from the upper canyon, nearly 100 times the volume loss per unit area observed on land, resulting in up to 210 m of headwall retreat and erasure of small gully systems. These shallow slides transitioned into flows, contributing to the 935 Mm3 gravity flow deeper in the canyon. Corrected digital elevation model (DEM) differencing shows submarine landslide volumes were 1.53 times larger than postevent estimates would predict. The sediment mobilized by shallow landsliding from the Kaikōura Canyon headwall provides valuable insights that could improve sediment gravity flow and submarine landslide hazard models. Despite the large sediment volume, no tsunami was generated, likely due to failure occurring as numerous small disaggregating slides. These findings indicate that landslide-driven tsunami hazard in active margin settings may be lower than expected.

DOI: 10.1130/G53867.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G53867.1/661410/Transient-evidence-of-shallow-coseismic-submarine