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标题：Physical and hydrodynamic properties of deep sea mining-generated, abyssal sediment plumes in the Clarion Clipperton Fracture Zone (eastern-central Pacific)
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作者：Benjamin Gillard ; Kaveh Purkiani ; Damianos Chatzievangelou 等
期刊名称：Elementa: Science of the Anthropocene
电子版ISSN：2325-1026
出版年度：2019
卷号：7
期号：1
页码：5-18
DOI：10.1525/elementa.343
出版社：BioOne
摘要：The anthropogenic impact of polymetallic nodule harvesting in the Clarion-Clipperton Fracture Zone is expected to strongly affect the benthic ecosystem.To predict the long-term, industrial-scale impact of nodule mining on the deep-sea environment and to improve the reliability of the sediment plume model, information about the specific characteristics of deep-sea particles is needed.Discharge simulations of mining-related fine-grained (median diameter ≈ 20 μm) sediment plumes at concentrations of 35–500 mg L–1(dry weight) showed a propensity for rapid flocculation within 10 to 135 min, resulting in the formation of large aggregates up to 1100 μm in diameter.The results indicated that the discharge of elevated plume concentrations (500 mg L–1) under an increased shear rate (G ≥ 2.4 s–1) would result in improved efficiency of sediment flocculation.Furthermore, particle transport model results suggested that even under typical deep-sea flow conditions (G ≈ 0.1 s–1), rapid deposition of particles could be expected, which would restrict heavy sediment blanketing (several centimeters) to a smaller fall-out area near the source, unless subsequent flow events resuspended the sediments.Planning for in situ tests of these model projections is underway.
关键词：Deep-sea mining;Sediment plume;Particle size;Aggregation;Settling velocity;