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By Kristian Drivenes, Steinar L. Ellefmo, Kurt Aasly, Ben Snook, Przemyslaw B. Kowalczuk, Rolf Arne Kleiv

"Since Ellefmo et al. (2014) published resource estimates of undiscovered seafloor massive sulfides (SMS) on the Arctic Mid-Ocean Ridge (AMOR), there has been an increased focus on establishing new knowledge about exploitation technologies for such deposits. This also includes understanding the process mineralogical properties of typical SMS deposits.The part of the AMOR that lies between Jan Mayen and the Svalbard Islands and is located within Norwegian jurisdiction and, as such, investigating the potential for mineral production from hydrothermal vent fields has been seen as strategic. The AMOR has been explored for active hydrothermal vent fields since early 2000s (Pedersen et al., 2010b). One of the active vent fields discovered, Loki´s Castle, is located in the northern part of Mohn´s Ridge. This vent field was first described by Pedersen et al., (2010a) and consists of two mounds, each approximately 100-150 m diameter and 20-30 meters high, hosting several active chimneys, up to 11 m high.Loki´s Castle has been selected as a case site in order to study the properties of typical SMS occurrences with respect to possible future deep-sea mining activities. As part of the MarMine cruise in 2016, the Loki Castle was visited and sampled for e.g. mineral characterization and mineral processing analyses. In total, more than 500 kg rock samples were collected using ROVs, and intended for further research (Ludvigsen et al., 2016). In addition to sampling mineralized rock fragments, survey data like bathymetry, magnetics and Underwater Hyperspectral Imaging (UHI) was collected using Automated Underwater Vehicle (AUV)."

Jan 1, 2017

By Timothy F. McConachy

Magmatic-hydrothermal activity in the South-West Pacific and SE Asian island arcs during the Tertiary has created a premier copper-gold province with numerous, commercially attractive base and precious metal deposits. This activity continues to the present day, especially in submarine sectors of those arcs where modern technologies enable direct observation of ore-forming processes in action. Until recently, however, the volcanic island arcs of Indonesia escaped such attention. The Indonesia-Australia Survey for Submarine Hydrothermal Activity (IASSHA), involved three cruises with KR Baruna Jaya VIII, focused particularly on the Sangihe arc; Tomini Bay, Sulawesi, including the vicinity of isolated Colo volcano; and the Sunda Strait including the neighborhood of Krakatau volcano. IASSHA 2001 and 2003 cruises studied the arc and behind-arc sectors of the Sangihe volcanic island chain extending northwards from Quaternary volcanoes on the northeastern tip of Sulawesi, near Manado, to the Kawio Islands near the border with the Philippines (Fig. 1). This chain lies above a west-dipping Wadati-Benioff seismic zone whose subduction trench is obscured by accreted sediments and mélange, forming the Talaud-Mayu ridge. West of the main active chain and extending northwards from Manado there is a subparallel ridge (The Manado Line) surmounted by a number of high (>2000 m) seamounts of uncertain age.

Jan 1, 2005

By Jan Magne Markussen

China, India and South Korea are three developing/newly industrialized countries that can show a very positive economic development in latter years. Moreover the three countries also feature amongst the countries with the highest level of activity in deep seabed mining today. India was the first country to achieve Pioneer Investor status in accordance with the UN Convention on the Law of the Sea. The country has carried out comprehensive exploitation of nodule deposits in the Central Indian Basin. India has an active programme for development of mining technology and internationally, India is probably the leading nation today as far as processing technology is concerned. China for its part has established a central coordination unit for its deep seabed involvement and its exploration and technology development is already well underway. South Korea has applied for Pioneer Investor status and much indicates that it will be allocated its own minesite in the autumn of 1994. The three countries are in mutual contact in the area of the Law of the Sea. Korea contacted both China and India when drawing up its application for pioneer investor status and allocation of minesite. However, no cooperation exists between the three regarding for example technology development, economic analysis or in studies of the environmental consequences. The main purpose of this paper is to focus on why and how the three countries would be well advised to cooperate in the above areas. Economic, technological and organizational aspects all point in that direction.

Jan 1, 1994

By Sang-Mook Lee

The Manus back-arc basin behind the New Britain Trench is one of the major sites of active seafloor hydrothermal vent-fields which are considered to be modern-day analogue of felsic volcanic-hosted polymetallic massive sulfide deposits abundant in ancient geological record. Many of these deposits represent multi-million dollar resources, and yet very little are known about the fundamental processes leading to their formation. In November 2000 January 2001, the PACMANUS hydrothermal system in this region will be targeted by the Ocean Drilling Program Leg 193 to investigate the internal anatomy. A number of observations that suggest that the tectonic, magmatic and hydrothermal processes in the eastern Manus basin spreading center are unusual in that they can not be explained by a simple back-arc opening due to subduction of the New Britain Trench. Geochemistry of submarine volcanoes in the eastern Manus basin, for instance, shows affinity to arc rather than back-arc type volcanoes. Yet these submarine volcanoes lie too faraway from the Benioff-Wadati zone. One hypothesis is that the magmatic and subsequent hydrothermal activity of this region is a direct result of the irregularities in the deep crust and upper mantle structure and that the tectonic process is controlled by the sharp inflection of the New Britain Trench. According to this hypothesis, the two major southeast-trending strike-slip faults in the eastern Manus Basin, Djaul and Weitin Faults, should extend farther down and join to the New Britain Trench. They would form a transform arm of the triple junction with the New Britain Trench southeast of New Britain Island and southwest of Bougainville Island forming the other two arms. A trench-trench-transform triple junction can not be stable over time, and therefore a slight change in the plate velocity may lead to a dramatic change in the configuration of the plate boundaries. If so, the instability of the triple junction may cause large tectonic deformations, such as mantle uplift under the Manus basin due to mantle rupturing by transform faults, and therefore may explain the arc-style volcanism and unusual compositions of hydrothermal deposits in the eastern Manus basin.

Jan 1, 2000

By Cheng Xiangzhou

The China's Pioneer area includes two parts. The topography in the western part is very different from that in the eastern one. The distribution of the manganese nodules in these two regions differs correspondingly China Ocean Mineral Resources Research and Development Association (COMRA) will take appropriate measures so that the next development will be adapted to the features of its potential minable area.

Jan 1, 1996

By Guillaume Blanc

The development of marine mining in the offshore areas adjacent to most of the insular and continental European States is limited by the complex and evolving nature of its legal regime on the basis of the relevant applicable international, European and domestic rules. As the development of marine mining requires investments in capital-intensive technologies, the bankable feasibility of marine mining projects is very much dependent on the legal security of mining rights, assets and operations in offshore areas. This is quite difficult to assess due to the constant accumulation of applicable and potentially conflicting international and domestic laws in these areas, in particular the coastal zone, the territorial sea, and the Exclusive Economic Zone (EEZ). The often conflicting interaction of international treaties, laws and regulations in offshore areas raises specific and major issues in terms of permitting processes, access rights, ownership rights over the mineral resources explored and mined, flag vs. coastal State jurisdiction over mining vessels and marine mining equipment, international environmental liabilities, and unitisation and multi-forum disputes. In addition, the determination of jurisdiction and the legal regime under which marine mining could take place is becoming even more complex with the development of EU Law and the recent revision of the International Law of the Sea, particularly the new extension regime of the EEZ and jurisdiction over the continental shelf.

Jan 1, 2004

By G. McMurray

The release by the U.S. Department of the Interior (DOI) of a Draft Environmental Impact Statement (DEIS) for the leasing of polymetallic sulfide minerals on the Gorda Ridge in December 1983 resulted in strong negative public reactions. The fundamental issues affecting federal-state relations included the amount of state involvement in the planning process and the continuing question of consistency (sensu Coastal Zone Management Act). The specific issues raised included the authority of DOI to lease nonenergy minerals offshore, the economic and strategic rationale for the proposed lease, and the adequacy of the DEIS. The questions of DEIS adequacy arose in three major areas: the lack of evidence for the existence of polymetallic sulfides on the Gorda Ridge, the lack of sufficient baseline data, and the lack of a mining scenario from which to assess potential impacts. The joint Federal-State Technical Task Force was formed in February, 1984 as part of an initial agreement between the State of Oregon and the Department of the Interior to work cooperatively. Other points in the agreement were (1) a reduction of any future proposed lease area from 40 million acres to no more than 4 million acres; (2) indefinite postponement of the lease sale; (3) deletion of the nearshore portion of the possible lease area covering the physical continental shelf and slope; (4) a commitment of a "tiered" EIS process; and (5) sharing of non-proprietary data with the public.

Jan 1, 1985

By Alexander Malahoff

Accumulation of cobalt -rich ferromanganese crusts on Pacific seamounts located off-ridge in the Hawaiian EEZ, represents a complex process that involves geologic aging of the seamounts, geographic transportation- of the seamounts on the Pacific plate during the past 80 million years, and geochemical history of the oceans for that period. A comparative study of the building and erosion processes of the young Loihi Submarine Volcano, located south of the Island of Hawaii , and the 80 million year old Cross Seamount, located west of Hawaii , shows that both edifices show wide armchair-shaped talus chutes and intervening ridges of exposed dikes. The similarity between the observed mass wasting process on Loihi and Cross suggests that the slopes of submarine volcanoes are geologically unstable from the time of their origin on the seafloor through their entire geological history. The slopes of Cross are covered by coalesced ferromanganese crust covered talus, steep exposed dike faces, and crust covered dike ridges. A study of the stratigraphy of the crusts shows a range of thicknesses and number of unconformities present. The thickest crusts, up to 8 centimeters, are found preserved within the larger coalesced slabs along the shallower slopes of the talus chutes and along the crests of the ridges between water depths of 400 and 1800 meters. The platinum content was used in stratigraphic correlation between the crusts in the coalesced slabs and those collected from ridges with the PISCES V submersible. In the samples studied, the highest platinum content of 0.7 ppm

Jan 1, 1991

By Philomene Verlaan

This study examines the possible relationships between compositional variability in non-hydrothermal manganese nodules and large-scale environmental parameters. In the central SW Pacific (145-180° W and 20-O° S) the level of primary productivity, the rates and proportions of carbonate, silica and organic matter supply to the sediments, and the position of the seafloor relative to the Calcium Carbonate Compensation Depth (CCD) appear to directly influence nodule composition. Four zones of nodule composition are apparent. These zones correlate fairly well with the level of primary productivity in surface waters, as estimated by satellite-based measurement of chlorophyll content. The observed correlations between surface productivity and nodule composition are consistent with the contention that the dominant source of several transition metals in these deposits (i.e , Mn, Ni, Cu. and Zn) is provided by removal of fine-grained particulate matter from the water column by biological means. Subsequent decay of organic matter in sediments augments the content of these metals in the nodules through oxic and sub-oxic diagenesis. The opposite behavior of Fe and Co content may in part result from mineralogical and dilution effects.

Jan 1, 2000

By Benoît Waquet

In a context of scarce mineral resources, coupled with an increasing global demand in metals due to the exponential growth of newly industrialized countries, the mining industry will inevitably have to deal with tomorrow?s resources: underwater deposits. Three types of offshore deposits are known to date: polymetallic nodules, cobalt-rich crusts and hydrothermal sulphides. The latter, regarding the political-economic context, is now considered most likely to be exploited in a near future. Operating a mine critically requires accurate knowledge on geotechnical properties of the ore. A question is thus to be asked: Is there a particular spatial organization of geotechnical properties in a hydrothermal sulfide mound? In the present study, geotechnical properties have been measured for 29 sulfide samples of known origin, completed by 14 measurements on Western Pacific specimens from Yamazaki et al. (1990) and Yamazaki and Park (2003). From these geotechnical data on 43 sulfide samples, we can provide some answers to this question above, crucial for future exploitation of underwater mines.

Jan 1, 2010

By E. Moriguchi, K. Tamaki, A. Okuda, K. Iizasa, C. Honsho

The northern Izu-Ogasawara Arc is characterized by an abundant distribution of submarine calderas along the volcanic front to the back-arc rift zones. In many of these calderas hydrothermal activities are observed. Among these calderas, hydrothermal ore deposits with economically feasible quality and amounts are hosted at two calderas, the Myojin Knoll Caldera and Beyonnaise Knoll Caldera. We conducted two research cruises in 2005 and 2006 to investigate further hydrothermal activities and ore deposits in these calderas and to complete the geological and geophysical mapping in the area. We discovered a strong signature of hydrothermal activity in the Myojin-sho Caldera using AUV capabilities. Newly obtained geological and geophysical data clarified the relationship between back-arc rifting tectonics and hydrothermal activities in the area. Five calderas (two of them newly found) and numerous (>200) volcanoes are mapped in the area. Complete SeaBeam coverage showed a distinct feature of the back-arc rifting activity and its relationship to the submarine calderas on the volcanic front. The back-arc rift zones composed of four segments separated by E-W trending volcanic ridges. Three of the calderas are located in the rift zone and are heavily deformed by the rift normal faulting that typically trend NNW-SSE. As the Beyonnaise Caldera is located in a swarm of faulting zones at the eastern end of the back-arc rift, the formation of the hydrothermal ore deposits found in the Beyonnaise Caldera are apparently affected by these faulting activities. Newly found submarine calderas are located in the rifting zone and are heavily faulted.

Sep 24, 2006

By Steve Potter

"REVIEW OF ISA's DRAFT EXPLOITATION REGULATIONS – HAVE KEY STAKEHOLDERS' CONCERNS BEEN ADDRESSED ADEQUATELY?In early August 2017, the ISA published a revised draft of the exploitation regulations. My presentation will focus on the extent to which key State and Contractor issues raised in formal submissions in November 2016 have been addressed in the revised draft and any additional key issues in the revised draft which are likely to cause significant concern for Contractors.ABSTRACTFollowing the ISA's call for submissions in response to draft zero of the exploitation regulations in July 2016, 43 responses from stakeholders were received by the ISA in November 2016. My presentation will start by briefly looking at how the ISA has continued to engage with stakeholders following the publication of draft zero of the exploitation regulations, including at payment regime workshops in London (November 2016) and Singapore (April 2017) and at the environmental workshop held in Berlin in March 2017. It will also touch on the publication in February 2017 of what was in effect a very preliminary draft of the environmental regulations before moving on to consider in detail the extent to which key State and Contractor issues have been addressed in the ISA revised draft exploitation regulations which were published in August 2017. My review of the formal submissions will include, amongst other things, commentary on:(i) the level of Stakeholder response (State Parties to UNCLOS, Sponsoring States, Privately owned Contractors, State Owned Contractors and NGOs);(ii) the quality of the submissions (particularly by States and Contractors); (iii) the key concerns raised by State and Contractor stakeholders and how those issues have been addressed in the revised draft exploitation regulations; and(iv) how all stakeholders need to further engage with the ISA to ensure that the exploitation code adequately addresses the legitimate and reasonable concerns of each Stakeholder group (e.g. Contractors, Sponsoring States, Developing States and NGOs)."

Jan 1, 2017

By Ulrich Von Stackelber

Deep sea mining of manganese nodules actually will have an environmental impact to the seafloor and to the water column. However, we are far from being able to predict the possible consequences. Therefore, in 1992 environmental studies were conducted with the R/V Sonne in a manganese nodule field of the Peru Basin. The bathymetry of the seafloor was mapped using the hydrosweep system and the distribution and type of sediments were investigated by the parasound system and by collecting surface samples and sediment cores. Deep towing of a side-scan sonar system revealed a Mn encrustation of sediments and a nodule coverage of variable density. Along the tracks of a photo sledge a great variability of bottom fauna and of bioturbation was observed. Bottom-mechanical investigations of surface-near sediments were completed on board. Additionally water samples were collected near the sea floor to determine character and amount of dissolved and suspended particles. Manganese nodules and crusts were collected at 80 locations. In many aspects the nodules differ from those of the Clarion-Clipperton Zone: Big cauliflower-shaped nodules with growth rates up to 160 mm/ Ma may reach a maximum size of 24 cm in diameter, maximum abundance may be 44 kg/m2, the mean size of buried nodules is greater than that of surface nodules. The reason for that difference is due to the relatively high bioproductivity in surface waters and to a Mn redox boundary in the sediment column 10 cm below the seafloor. Histograms of nodules showing the distribution of size and growth type clearly indicate that the growth history is different for basins, slopes and tops of seamounts and ridges. Nodules with diameters >7 cm show mainly diagenetic and to a minor degree hydrogenetic growth. Smaller nodules of the same assemblage are composed mainly of hydrogenetically grown Mn oxide. The optimum diagenetic growth occurs within the sediment immediately above the Mn redox boundary, a level which is not reached by the small nodules.

Jan 1, 1994

By A. Ivanova

The continental shelves occupy a vast area of Russia and contain complexes of commercial placer minerals. Of prime importance are Cenozoic placers of valuable minerals including gold, cassiterite, diamonds, chromite, platinoids, and minerals of titanium, zirconium and rare earth elements, biogenic amber and fossil ivory (1). Commercial placer minerals are associated with shelf placer formation zones (SPFZ). These zones are located at junctions of marginal orogens and shelf troughs in morphostructures where upwarping, subsidence, and sign-variable neotectonic movements are not significant. The SPFZs are characterized by ancient buried leveling planes with mantles of waste, series of wave-cut aggradation terraces on land and beneath the sea, and drowned and buried stream valleys. The occurrence of mineral placers in the SPFZs was caused by endogenic mineralization and exogenic placer hosted formation. Concentrations of commercial biogenic minerals are associated with areas of burial of biogenic material (release of resins by plants and theriofauna thanatocoenoses) and with their transition zones. Since the Oligocene, alternations in marine transgression-regression have dominated the shelf areas. This has resulted in the formation of polygenic placers. Climatic conditions are of great importance: warm and humid climate in the Paleogene-Neogene changed to colder climates in the late Pliocene (polar type sedimentation; formation of permafrost strata and sea glaciation). These events are responsible for the regularity in placer formation during the Cenozoic in which the early Cenozoic (Eocene-Oligocene-Miocene) and late Cenozoic (late Pliocene-early Pleistocene and late Pleistocene-Holocene) epochs are prominent.

Jan 1, 2004

By D. S. Limpenny

Marine benthic habitats are vulnerable to the influence of a wide range of anthropogenic activities (e.g. sand and gravel extraction, dredged material disposal and trawling). Traditionally, benthic ecologists have relied on point sampling techniques such as grabs, corers and dredges to provide information on the physical nature of the substrates and their associated benthic fauna. However, information of this nature only relates to the specific point on the seabed from which the sample was collected and the interpolation of such data to predict the wider distribution of substrata and associated fauna may be unreliable. Our approach uses a range of acoustic, photographic and physical sampling methodologies to produce continuous acoustic coverage maps which can be used to assist with the interpretation of faunal distributions. This approach has been used to assess the impacts of marine sand and gravel extraction at the seabed at two sites off the east coast of England in the southern North Sea. The first study site (designated ?Area 222?) is located 20km off the southeast coast of England and was surveyed in 2001 using sidescan sonar, single beam bathymetry, seabed photography and also a 0.1m2 Hamon grab for the collection of benthos and sediment samples. The main objectives of this investigation were to provide an indication of the spatial distribution of the sediments and macrofauna in the wider area encompassing the dredged site, to evaluate the scope for the effects of marine sand and gravel extraction to extend beyond the boundaries of the site and to provide a wider geographical context for time series investigations. At this site, an acoustic basemap was utilised in conjunction with faunal sampling and photographic groundtruthing, to determine the nature and distribution of the seabed sediments and their associated features. Disturbances at the seabed arising from historic sand and gravel extraction activities were mapped, and this information was helpful in establishing biological cause and effect relationships. The acoustic basemap was also used to target biological reference sites against which the effects of adjacent man-made disturbances could be evaluated.

Jan 1, 2004

By Sabrina Warwas, Thomas Kuhn

"Due to rising prices and increasing demand of raw materials over the last years, marine mineral resources including manganese nodules have become a focus of study for industry and science. Marine ferromanganese nodules consist of micro-layers of different chemical and mineralogical composition which incorporate metals of high economic interest (Ni, Cu, Co, Zn, Mo, Li, rare earth elements; Hein & Koschinsky, 2015).The varying composition of the layers depends on different growth processes, such as hydrogenetic (metal precipitation from the water column under oxic conditions; Mn/Fe = 3), diagenetic (metal precipitation from the sediment pore water) under oxic (Mn/Fe 3-10) or suboxic (Mn/Fe = 10) conditions; (Wegorzewski & Kuhn, 2014) or hydrothermal (metal precipitation from low-temperature hydrothermal fluids; Kuhn et al., 2003).METHODSIn this study, manganese nodules from three different locations of the Atlantic Ocean (Galicia Bank; Vema-Fracture-Zone and Brazilian Basin) were analyzed for their geochemical and mineralogical composition. Detailed information about the samples are given in table 1. The geochemical and mineralogical composition of bulk nodules were determined by XRF, ICP-MS/OES as well as XRD and the single micro-layers by high resolution analyses with electron microprobe and LA-ICP-MS."

Jan 1, 2017

By Glen Smith

Nautilus Minerals is the world leader in exploration and development of deep ocean seafloor massive sulphide (SMS) resources. The company is currently focused on generating its resource pipeline in the Western Pacific and its first development project for recovery of high-grade copper, gold and silver mineralisation from its Solwara 1 site in the Bismarck Sea, Papua New Guinea. The Solwara 1 site is located at a water depth of 1,600 ? 1,800 meters. Over 150 SMS seafloor surface samples have been collected from chimney structures during dives made by remote operated vehicles (ROVs). In order to obtain an understanding of the sub-surface mineralisation, Nautilus carried out 4 drilling programs between 2006 and 2010 which allowed the calculation of a Canadian NI43-101 compliant resource estimate. The initial 2006 campaign was based on conventional offshore surface driven drill equipment. In conjunction with the subsea remote technology industry, Nautilus subsequently developed an ROV operated seafloor drill system with improved drill core recovery and efficiency. This technology was developed further with a 2010 - 2011 drill program to increase the available geological knowledge at Solwara 1 and adjacent prospects. his paper will provide an overview of Nautilus? SMS drilling requirements and recap the evolution of drilling technology and operations undertaken at Solwara 1 from 2006 to 2011. The paper will also discuss the potential of further developments in drilling techniques and equipment to increase or improve drilling depth, efficiency and data quality.

Jan 1, 2011

By Jun Lu

Compared with land mineral resources investigation, as well known, it is more important for marine geologists to get image data (e.g. photographs, video tapes and various charts) because they are often hard to reach deep seabed directly. In the past years a plenty of image data which are in various forms have been accumulated. In contrast with both digital and character data managing the image data by using database is just unfolding and it will be a trend for marine mineral resources investigation. GIS (Geography Information System) offers another useful means of processing image data, especially geological data. GIS is characterized by processing vector data (e.g. point, line and polygon), but newer versions of GIS software package are also able to process raster data (e.g. photographs etc.). The present author made a presentation on marine mineral image database during 25th UMI, but that system runs under DOS environment and dealt with only mineralogy. Recently a new system which integrates Oracle image database with GIS (ArcView version 3.1) has been developed. This system runs under Windows NT environment. In the network environment Server/Client mode is adopted, and over 200 basic subdatabases (tables)are located on Server; operating interfaces are located on several clients so that several persons can operate the system simultaneously. The whole system involves five types of marine mineral resources: manganese nodules, cobalt-rich crusts, polymetallic sulfides, phosphorites and gas hydrates. The data of every type of marine mineral resources described above are distributed among five units and several blocks. The units and blocks are described below:

Jan 1, 2000

In 1983, the GEMINO research project (Geothermal Metallogenesis Indian Ocean) was initiated in order to locate and evaluate sites of recent or fossil hydrothermal activity in the largely unexplored Indian Ocean. During GEMINO cruises 1 and 2 with R/V SONNE in 1983 and 1986, the Central Indian Ridge between 21°S and 24°S was the subject of detailed exploration, including SeaBeam and magnetic mapping, hydrocasts, sediment coring, TV-grab sampling, and camera/video tows. Although hydrothermal sulfide mineralization was not located, a hydrothermal component in the sediment composition, hydrothermally altered basalts, and maximum concentrations of 27.5 nmol/kg Mn and 45.6 nl/l CH4 were discovered (Plüger and Herzig 1986; Herzig and Plüger 1988a). Leg 1 of the GEMINO-3 cruise in 1987/88 identified a neovolcanic ridge in the rift valley of a 30 km segment at 22°55'S as a site of weak hydrothermal activity and photographed smectite-like precipitates on basalt talus and a chimney structure on top of a ridge-parallel fault scarp. Water temperature data and the distribution of Mn and CH4 were interpreted as indicative of diffuse, low-temperature hydrothermal activity (Herzig and Plüger 1988b).

Jan 1, 1989

By Seung-Kyu Son

This study was investigated about physico-chemical parameter such as water temperature, salinity, inorganic nutrients and total organic carbon (TOC). CTD (Model: Sea-Bird 911 Plus) castings were carried out on two transects in the northeast equatorial Pacific Ocean. As a part of the Korea Deep-sea Environment Study (KODES), inorganic nutrients and TOC were determined at 41 stations located from 131° to 136°W along 10.5°N and from 17° to 5°N along 131.5°W (Fig. 1). We particularly chose KODES Long-term Monitoring Station (St. KOMO) to observe for the annually environmental baseline study in the contract area. [ ]

Jan 1, 2005