Relationship between polymetallic nodule genesis and sediment distribution in the KODOS (Korea Deep Ocean Study) Area, Northeastern Pacific

2012 ◽  
Vol 47 (3) ◽  
pp. 197-207 ◽  
Author(s):  
Jonguk Kim ◽  
Kiseong Hyeong ◽  
Hyun-Bok Lee ◽  
Young-Tak Ko
Keyword(s):  
Deep Ocean ◽  
Sediment Distribution ◽  
Polymetallic Nodule ◽  
Northeastern Pacific ◽  
Ocean Study

Development and Subsea Testing of Polymetallic Nodule Crusher for Underwater Mining Machine

2021 ◽  
Vol 55 (6) ◽  
pp. 65-72
Author(s):  
Narayanmurthy Renganayahi Ramesh ◽  
Karuppiah Thirumurugan ◽  
Deepak Chullickal Raphael ◽  
Gidugu Ananda Ramadass ◽  
Malayath Aravindakshan Atmanand
Keyword(s):  
Minimum Weight ◽  
Deep Ocean ◽  
Maximum Size ◽  
Mining Machine ◽  
Design Synthesis ◽  
Polymetallic Nodule ◽  
Polymetallic Nodules ◽  
Underwater Mining ◽  
Nodule Mining ◽  
Ocean Environment

Abstract Polymetallic nodules found in the deep oceans are viewed as potential resources for meeting the world's demand of many metals in the near future. Polymetallic nodule mining systems require subsea crushing systems for reducing the size of nodules to facilitate energy-efficient and safe pumping through risers of optimum size. Polymetallic nodules are friable, and deep-sea crushing has to be done with care to minimize the formation of fines, while obtaining the required size reduction. The crusher could also encounter objects with greater hardness during operation like small rocks, splinters, long fish bones, and shark teeth. All components in the crusher should be capable of operating in the deep ocean environment, which is hyperbaric and sediment laden. The equipment should be compact with minimum weight. Reversal of direction and dumping arrangements in the event of stalling are other essential design requirements. An underwater crusher capable of crushing mined nodules from a maximum size of 100 mm to a crushed size of 30 mm was developed using principles of design synthesis. The crusher was tested in land and integrated into a remotely operated crawler-based underwater mining machine that could mine and pump nodules through a flexible riser. The system was tested using artificial nodules at 512-m water depth off the Malvan coast in the Arabian Sea. This paper describes developmental methodology, land-based performance tests, and sea trials conducted on the developed crusher.

scholarly journals Controls on the origin and evolution of deep-ocean trench-axial channels

Geology ◽  
2021 ◽  
Author(s):  
Adam D. McArthur ◽  
Daniel E. Tek
Keyword(s):  
Subduction Zones ◽  
Three Dimensional ◽  
Plate Boundary ◽  
Deep Ocean ◽  
Sediment Supply ◽  
Turbidity Currents ◽  
Primary Control ◽  
Sediment Distribution ◽  
Origin And Evolution ◽  
Axial Channel

The type and volume of sediment entering subduction zones affects the style of plate-boundary deformation and thus sedimentary and tectonic cycles. Because submarine channels significantly increase the transport efficiency of turbidity currents, their presence or absence in subduction trenches is a primary control on trench fill. To date, comprehensive architectural characterization of trench-axial channels has not been possible, undermining efforts to identify the factors controlling their initiation and evolution. Here, we describe the evolution of the Hikurangi Channel, which traverses the Hikurangi Trench, offshore New Zealand. Analysis of two- and three-dimensional seismic data reveals that the channel was present only during the last ~3.5 m.y. of the ~27 m.y. of the trench’s existence; its inception and propagation resulted from increased sediment supply to the trench following amplified hinterland exhumation. To test if the controls on the evolution of the Hikurangi Channel are universal, multivariate statistical analysis of the geomorphology of subduction trenches globally is used to investigate the formative conditions of axial channels in modern trenches. Terrigenous sediment supply and thickness of sediment cover in a trench are the dominant controls; subsidiary factors such as trench length and rugosity also contribute to the conditions necessary for trench-axial channel development. Axial channels regulate sediment distribution in trenches, and this varies temporally and spatially as a channel propagates along a trench. The presence of a trench-axial channel affects plate-boundary mechanics and has implications for the style of subduction-margin deformation.

scholarly journals Geochemistry of rare earth elements in two-color core sediments from the Korea Deep Ocean Study (KODOS)-90 site, NE equatorial Pacific.

1998 ◽  
Vol 32 (5) ◽  
pp. 281-299 ◽  
Author(s):  
Hoi-Soo Jung ◽  
Man-Sik Choi ◽  
Dongseon Kim ◽  
Hyun-Ju Cha ◽  
Kyeong-Yong Lee
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Deep Ocean ◽  
Equatorial Pacific ◽  
Core Sediments ◽  
Ocean Study

Paleomagnetic results from deep-sea sediment of the Korea Deep Ocean Study (KODOS) area (northern equatorial Pacific) and their paleodepositional implications

2004 ◽  
Vol 24 (2) ◽  
pp. 112-124 ◽  
Author(s):  
Cheong-Kee Park ◽  
Seung-Kyu Son ◽  
Ki-Hyune Kim ◽  
Sang-Bum Chi ◽  
Seong-Jae Doh
Keyword(s):  
Deep Sea ◽  
Deep Ocean ◽  
Equatorial Pacific ◽  
Deep Sea Sediment ◽  
Ocean Study

scholarly journals From sea surface to seafloor: a benthic allochthonous eDNA survey for the abyssal ocean

2020 ◽  
Author(s):  
Olivier Laroche ◽  
Oliver Kersten ◽  
Craig R. Smith ◽  
Erica Goetze
Keyword(s):  
Water Column ◽  
Deep Sea ◽  
Anthropogenic Impacts ◽  
Spatial Scales ◽  
Deep Ocean ◽  
Environmental Dna ◽  
Benthic Boundary Layer ◽  
Large Sample Size ◽  
Polymetallic Nodule ◽  
Nodule Mining

AbstractDiverse and remote deep-sea communities are critically under-sampled and increasingly threatened by anthropogenic impacts. Environmental DNA (eDNA) metabarcoding could facilitate rapid and comprehensive biotic surveys in the deep ocean, yet many aspects of the sources and distribution of eDNA in the deep sea are still poorly understood. In order to examine the influence of the water column on benthic eDNA surveys in regions targeted for deep-sea polymetallic nodule mining, we investigated the occurrence of pelagic eDNA across: (1) two different deep-sea habitat types, abyssal plains and seamounts, (2) benthic sample types, including nodules, sediment, and seawater within the benthic boundary layer (BBL), and (3) sediment depth horizons (0-2 cm, 3-5 cm). Little difference was observed between seamounts and the adjacent abyssal plains in the proportion of legacy pelagic eDNA sampled in the benthos, despite an > 1000 m depth difference for these habitats. In terms of both reads and amplicon sequence variants (ASVs), pelagic eDNA was minimal within sediment and nodule samples (< 2%), and is unlikely to affect benthic surveys that monitor resident organisms at the deep seafloor. However, pelagic eDNA was substantial within the BBL (up to 13 % ASVs, 86% reads), deriving both from the high biomass upper ocean as well as deep pelagic residents. While most pelagic eDNA found in sediments and on nodules could be sourced from the epipelagic for metazoans, protist legacy eDNA sampled on these substrates appeared to originate across a range of depths in the water column. Some evidence of eDNA degradation across a vertical sediment profile was observed for protists, with higher diversity in the 0-2 cm layer and a significantly lower proportion of legacy pelagic eDNA in deeper sediments (3-5 cm). Study-wide, our estimated metazoan sampling coverage ranged from 40% to 74%, despite relatively large sample size. Future deep-sea eDNA surveys should examine oceanographic influences on eDNA transport and residence times, consider habitat heterogeneity at a range of spatial scales in the abyss, and aim to process large amounts of material per sample (with replication) in order to increase the sampling coverage in these diverse deep ocean communities.

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