近日，同济大学张艳伟团队的最新研究探明了浊流调节深海海底峡谷中微塑料的运输和沉降过程。相关论文于2024年6月4日发表于国际顶尖学术期刊《地质学》杂志上。

据报道，微塑料在深海中广泛分布，海底峡谷中的微塑料浓度最高，且被认为与浊流密切相关。然而，浊流在微塑性运输和沉降中的作用尚不清楚。

研究人员展示了中国台湾近海高平峡谷堤防沉积物捕集器手机的观测资料，以分析其微塑料丰度与沉降通量的时空变化。结果表明，相对较高的微塑性丰度和通量与浊流主导的近底悬浮泥沙浓度的增加是一致的。微塑料以聚丙烯(59%)和聚乙烯(21%)为主，可能来源于中国台湾沿海沉积物和河流输入，然后通过台风或地震引发的浊度流进入海底峡谷。

浊流期间，微塑料平均丰度和通量分别为每千克4137个颗粒和每天每平方米40.11个颗粒，分别比非浊流期间增加49%和270%。浊流期间的微塑性通量占年通量的76%。研究结果强调，浊流是调节海底峡谷中微塑料运输和沉降的主要水动力过程。

附：英文原文

Title: Turbidity currents regulate the transport and settling of microplastics in a deep-sea submarine canyon

Author: Xiaodong Zhang, Zhifei Liu, Daoji Li, Yulong Zhao, Yanwei Zhang

Issue&Volume: 2024-06-04

Abstract: Microplastics are widely distributed in deep oceans, with some of the highest concentrations reported in submarine canyons, which are thought to be closely related to turbidity currents. However, the turbidity current role in microplastic transport and deposition is poorly understood. Here, we present temporal variation in microplastic abundance and settling flux from sediment trap observations on the levee of Gaoping Canyon, offshore Taiwan China, where turbidity currents occur frequently. The results showed that relatively high microplastic abundance and flux were consistent with the increases of near-bottom suspended sediment concentration caused by turbidity currents. The microplastics, dominated by polypropylene (59%) and polyethylene (21%), were probably derived from Taiwan China coastal resuspension and river input and then transported into the submarine canyon by typhoon- or earthquake-triggered turbidity currents. During the turbidity currents, the average microplastic abundance and flux was 4137 particles per kilogram and 40.11 particles per square meter per day, respectively, showing an increase of 49% and 270%, respectively, compared to nonturbidity current periods. The total microplastic flux during the turbidity currents accounted for ～76% of annual flux. Our study highlights turbidity currents to be the major hydrodynamic process in regulating microplastic transport and settling in a submarine canyon.

DOI: 10.1130/G52116.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G52116.1/644688/Turbidity-currents-regulate-the-transport-andredirectedFrom=fulltext