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Physical and hydrodynamic properties of deep sea mining-generated, abyssal sediment plume in the Clarion Clipperton fracture zone (eastern-central Pacific)

Citation

Gillard, Benjamin et al. (2018), Physical and hydrodynamic properties of deep sea mining-generated, abyssal sediment plume in the Clarion Clipperton fracture zone (eastern-central Pacific), DataONE Dash, Dataset, https://doi.org/10.15146/R3K966

Abstract

The anthropogenic impact from 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, the behavior of deep-sea particles has to be provided to improve sediment plume model reliability. Discharge simulations of mining-related fine (d50≈ 20 mm) sediment plumes with a concentration of 35 -500 mg L-1indicate a rapid flocculation propensity within 10 to 135 minutes, resulting in the formation of large aggregates that are up to 1100 mm in size. A clear deviation of the range of settling velocities (7 - 355 m d-1) of large plume aggregates (>100 mm) was observed from model-based calculations (e.g. Stokes). Our findings indicate that discharge of a high plume concentration (500 mg L-1) under elevated shear rate (G ³2.4 s-1) would result in an optimum sediment flocculation efficiency. Furthermore, our model results suggest that even under typical deep-sea flow conditions of low shear rate a relatively fast deposition of particles can be expected and, thereby, restrict the blanketing to a relatively small fall-out area near the source.

Methods

Please refer to the main manuscript 

Usage Notes

Excell document with every sheet containing the raw data from one figure published with our manuscript.