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By Sang Bum Chi

In order to better predict and manage benthic disturbance by deep seabed manganese nodules mining, we needed to conduct a benthic disturbance experiment at the selected area, which has a similar environmental condition as the preservation reference area. Therefore, we have performed environmental baseline studies from 2003--not only to select the benthic environmental impact testing site but, also to detect any environmental changes before and after mining activity. Since then, a large dataset of various parameters ranging from physical (e.g. temperature, salinity, current, weather), chemical (e.g. dissolved oxygen, nutrients, dissolved and particulate organic carbon), biological (e.g. bacteria, plankton, benthos), geological (e.g. Mn-nodule abundance, sediment shear strength) and others (e.g. bathymetric profile and slope, mass flux) have been accumulated. Using this dataset, descriptive statistics and cross-correlations were performed to select the benthic environmental impact testing site. Outcome of this analysis suggests that the potential benthic impact testing site would be a rectangular-shape area (10 km × 10 km) and located at 10°27'~10°33'N, 131°53'~131°58'W, which is latitudinally the same as the preservation reference area.

Jan 1, 2011

By Allan Spencer

In March 2007, Nautilus Minerals Inc. announced that they had commenced their 2007 exploration and development program with the mobilization of the Research Vessel Wave Mercury and the Survey Vessel Aquila onsite Papua New Guinea.

By Takashi Ito

Numerous studies have examined the distribution of deep-sea manganese deposits throughout geologic history. Here I summarize the recent results, focusing on the frequency of occurrence, burial age and mechanism, and the paleoceanographic implications.

By Simon McDonald

The Neptune Group was established in 1999 to apply for exploration permits within New Zealand’s 200nm EEZ. These applications were to investigate and commercialise hydrothermal Seafloor Massive Sulphide (SMS) deposits identified by international researchers and to locate others. SMS are volcanically related seafloor accumulations of copper, lead and zinc with high levels of gold and silver. Neptune has three granted exploration licenses within the New Zealand EEZ and has application in other jurisdictions. Neptune undertook the world’s first commercial drilling exploration work of SMS in December of 2005.

Aug 24, 2006

By M. E. Williamson

A seafloor based robotic drilling system is being developed for the National Institute of Ocean Technology in Chennai, India to support a National initiative for marine methane hydrate research. The system will be capable of core sampling to 150m below the seafloor in 3000m of water under telemetric control of an operator onboard a research vessel at the surface. Unlike previous robotic drilling systems, this unit (designated the ACS) will use wireline methodology to reduce the number of tool handling operations required to complete the borehole (conventional rod drilling requires 2025 tool handling operations to complete a 100m hole, while wireline requires only 48 operations to reach the same depth).

By Kokichi Iizasa

Modern Kuroko-type deposits have been much reported in submarine calderas and cauldrons in the EEZ of Japan since 1988. Some of them have been found based on heavy mineral analysis of sediments in which sulfide particles may be derived from hydrothermal sources in the ambient areas. From the end of August to early September 2007, in the middle Izu-Ogasawara arc south of Tokyo, ROV expeditions were carried out in submarine calderas in order to examine mineralogical features between intact heavy particles spouting out from sulfide chimneys and heavy minerals such as sulfides in sediments around sulfide mounds in Kuroko-type deposits, and to find more newly formed hydrothermal sulfide fields in those areas. Some preliminary results from the ROV expeditions are reported here.

Oct 15, 2007

By Evgeny G. Gurvich

While direct study of high temperature hydrothermal activity and the associated mineral formation as well as study of their scales are possible in the modern ocean, researchers are deprived of such opportunity for past geologic time. Even in cases where hydrothermal deposits that formed in the geological past are preserved they have been covered by sediments or overlain by lava and have become inaccessible after a time for obser-vation and sampling. Rarely are these buried hydrothermal deposits found during deep-sea drilling or coring operations, and their direct study on an ocean scale is impossible at present. Even within hydrothermal fields, without special preliminary detailed surveys, the probability of intersecting hydrothermal edifices that are covered by sediments becomes a rare event.

Aug 24, 2006

By Sup Hong

Herein, concept designs of two different types of mining robots are concerned, which are aimed for developments of deep seabed mineral resources: polymetallic nodules (PMN) and seabed massive sulfides (SMS), respectively. Continuous mining concepts are presented based on technical and environmental feasibility, where the environmental and functional differences for commercial productions are investigated. Needs and roles of versatile mining robots are explained as a key of continuous mining system. The functional requirements and design characteristics of mining robots to satisfy the top requirements from customers are described comparatively. Schemes of axiomatic design and quality function deployment (QFD) are utilized: functional requirements (FR) are defined, technical requirements (TR) are figured out, design parameters (DP) are derived, and degrees of importance of design parameters are evaluated. Analogy and discrepancy in remote operation methods are put side by side. A pilot scale mining robot for PMN and a commercial scale one for SMS are suggested in form of concept designs. PMN mining robot is shaped as a multiple configuration of unit robot modules in side dimension, in which the unit robot module consists of two tracks and two pick-up modules. SMS mining robot is based on a four-tracked vehicle. Main platform is mounted on the vehicle through turn-table. Excavation device consists of two-articulated boom and cutter tool. Crushing-and-pumping units are placed same in both robot platforms.

Jan 1, 2011

By Timothy F. McConachy

Hydrothermal fluids emanating from the seafloor rise as buoyant plumes, entraining ambient bottom sea water on the way up, until they reach density equilibrium and spread laterally in a direction that is governed by near-bottom currents. Plumes provide targets for focussing exploration for seafloor polymetallic sulfide deposits associated with active hydrothermal vents because their lateral and vertical extent is commonly orders of magnitude larger than the vent field from which they originate. Black smokers can inject on the order of 10,000 µg of particles per liter into a sea water column that normally contains only about 10 µg of particles per liter. The resulting plume should be characterized by increased particulate concentration with respect to background sea water and, therefore, provide a measurable gradient towards the source of venting. By utilizing the ability of particles to scatter light, we employed a real¬time, acoustically telemetered, nephelometer to measure this gradient, and mapped the size, shape and particle concentration of plumes at an active spreading center on the Southern Explorer Ridge at lat 49°45.6'N and long 130°16.2'W. Isopach and particle concentration data indicate the presence of two separate but overlapping plumes. The first is associated with a known vent field called Magic Mountain; the second with a new field called AGOR 171, 1.2

Jan 1, 1986

By D. S. Cronan

Mineral exploration problems in the S.W. Pacific are not unique to that region, but a combination of favourable circumstances render it an ideal area to attempt to solve such problems. The land area of the S.W. Pacific island nations is only a fraction of the total sea area they can claim under current International Law. Hence, they have a great need to explore and evaluate their offshore areas. For the past ten years the focus of this work has been CCOP/SOPAC which has individually and jointly with other groups initiated and maintained far reaching marine mineral exploration programmes. In association with CCOP/SOPAC the writer has obtained and analysed approximately 650 sediment samples from the S.W. Pacific region for seventeen elements. Multivariate statistical techniques have been applied to the data set. The aim has been to identify chemically anomalous sediments reflecting either sea floor mineralisation and/or mineralisation on adjacent land areas.

Jan 1, 1985

By V. K. Banakar, R. P. Rajani, A. R. Chodankar

The Afanasiy-Nikitin Seamounts (ANS) in Eastern Equatorial Indian Ocean (Figure 1) are shown to be the exposed part of the presently buried 85°E Ridge system under the Bengal Fan sediment and were emplacement around 75-80 m.y. ago (Krishna, 2003). The first recovery of ferromanganese crusts from the ANS was made during 1994, and the samples (Figure 2) provided important clues on the evolution of this seamount (Banakar et al., 1997).

By Akira Usui, James R. Hein, Rachel Dunham

Ferromanganese crusts are found on most hard-rock substrates in the deep ocean (800-3,000 m). Their distributions on seamounts are complex and controlled by a wide-variety of factors including seamount morphology, current patterns, mass wasting, substrate rock type and age, subsidence history, and others. However, the development of this potential resource ultimately depends on this distribution, as well as on the small-scale topography, grade, and tonnage. The parameters that will ultimately be used to define a mine site are unknown, but reasonable assumptions based on 25 years of data collection can be used to bracket likely permissive characteristics.

By I. V. Kubrakova, O. A. Tyutyunnik, M. L. Getsina, A. M. Asavin

An analysis of noble metals (NM) in natural samples is most problematic. Determination of their traces in geochemical samples, in part, for the purpose of deposit evaluation, is a difficult analytical task. A number of international standard reference materials of rocks and ores, in which NM content is certified, is estimated at a half dozen. For example, in the International proficiency test for analytical geochemistry laboratories (GeoPT), which is held by the Department of Earth Sciences (The Open University, United Kingdom), the data for gold and platinum are observed very rarely, and the results obtained in different laboratories differ on 1-3 orders of magnitude. It is caused by low contents of NM in nature, by a variety of their complex and mineral species, as well as by a complicated matrix composition of platinum-containing objects. Among these objects are ferromanganese ores, enriched strongly with Fe, Mn, Ni, REEs - the elements hampering a precise determination of NM due to a complexity of instrumental inter-element correction. The absence of the reliable methods of NM determination in these ores drastically limits the possibility of deposit evaluation.

By J. R. Woolsey

The cost of an offshore exploration project is mainly dependent on the size of the vessel engaged for the work and increases dramatically with increasing size. Of the various factors influencing vessel size, the type and size of the sampling equipment is typically the principal consideration. This scenario is particularly true of shallow sampling programs employing a vibracore system. The problem develops when certain bottom materials such as densely packed fine sand require sampling. This type of material being one of the most difficult for the standard vibracore systems, with integral core liner, to penetrate to a reasonable depth of some five to seven meters. The problem is mainly related to the excessive cross sectional area of the cutting bit required to accommodate the core liner. The typical solution has been to apply more power to the vibracore drive head which results in a considerable scale-up for the entire system with attendant increase in vessel size. In order to reduce operating cost, M.M.R.I. has developed several systems for deployment from vessels in the 20 meter range. Two systems are modifications to the basic vibracore and a third is a vibralift system. Basically, one of the vibracore units is employed where core liners are required, utilizing a special jet bit designed to reduce the cutting pressure on the bit while not affecting the integrity of the core. The other designed for core extrusion on

Jan 1, 1986

By Eric J. Foell, Hjalmar Thiel, Gerd Schriever

Environmental studies for the mining of polymetallic nodules (PN) from the deep sea may be traced back for some 35 years.

By Steven D. Scott

A geologist can be likened to a medical pathologist trying to figure out from faint clues how something had lived and how it died, often long after the event. Present-day seafloor hydrothermalism has empowered geologists/pathologists to dissect a living system, in this case volcanogenic massive sulfides (vms) deposits of copper, zinc, lead, silver and gold. On the other hand, a considerable amount of our understanding of seafloor hydrothermal processes and its products stem from our knowledge, much of it from industry, of these same processes and products that formed ancient ores in oceans as much as 2700 million years ago and are now mined on land.

Aug 24, 2006

By Timothy F. McConachy, Christopher J. Yeats, Ray Binns

Various kinds of sediment-hosted polymetallic sulfide deposit are known on land in ancient marine sequences, many tending to be larger and more valuable than massive sulfide deposits genetically associated with volcanic host rocks. Often such deposits are attributed to subhalative or shallow sub-seafloor precipitation processes, and structural control by faulting is commonly evident. Apart from the famous but anomalous Red Sea metallic oozes and several NE Pacific sites (Middle Valley, Escanaba Trough, Guaymas Basin), however, modern analogs of the sediment-hosted polymetallic sulfide category are lacking. Some deposits hosted by volcaniclastic rocks, such as JADE (Okinawa Trough) and Suzette (Eastern Manus Basin) are strictly sediment-hosted, but their formation is associated with the igneous activity and they are better considered a variant of the more abundant volcanic-associated polymetallic sulfide deposits.

Aug 24, 2006

By Nobuyuki Okamoto

Ferromanganese crusts on the seamounts in the Pacific Ocean are potential resources of cobalt, nickel, platinum and REEs. Particularly, those of the Republic of Marshall Islands and the Federated States of Micronesia (FSM) waters are believed to be of the highest resources potential area in the Pacific Ocean. The total six cruises using the Japanese Research Vessel Hakurei Maru No. 2 were carried out in the seamounts of the Marshall Islands in 1996, 1998 and 2002, and of the FSM in the 1997, 1998 and 2005 for evaluation of economic potential for cobalt-rich ferromanganese crusts as part of the Japan-SOPAC joint project. During these cruises numerous data such as bathymetric, geological, geophysical and environmental data were obtained. Geophysical exploration with backscatter mapping and side scan sonar, visual imaging using towed TV camera and geological sampling using dredge bucket and/or benthic multi-coring system (BMS) were conducted on these seamounts. In this presentation, we will report the mode of distribution of the crusts and calculated resource estimation based on the results of these geological and geophysical shipboard survey and land-based analyses. Keywords: ferromanganese crusts, Marshall Islands, Micronesia, resource potential

Jan 1, 2011

By Yanis Miezitis, Gerald Mueller, Timothy F. McConachy, Ronald G. Sait, Keith R. Porritt, William J. McKay

In November 2004, Australia lodged with the United Nations Commission on the Limits of the Continental Shelf possible new maritime boundaries in relation to Australia’s continental shelf extending beyond 200 nautical miles from the Territorial Sea Baseline (Colwell and Symonds, 2005). If agreed by the commission, just over half of Australia’s land mass will lie below the sea, and Australia will have one of the largest marine jurisdictions in the world (14.41 million km2). With this jurisdiction comes a responsibility to manage and sustain the marine environment (McConachy, 2006). Knowledge of minerals and their resource potential is part of this responsibility but is generally poorly known (McConachy, 2005).

Aug 24, 2006

By Colin Devey

As marine research scientists we especially appreciate the uniqueness and complexity of the deep-sea hydrothermal vent fauna and environments, and are particularly interested in preserving vents for their scientific, aesthetic, ecological, and potential economic values. In fact, because of the specialized nature of the equipment required to work at deep-sea hydrothermal vents, such as occupied and unoccupied research submersibles, scientists are the primary group of people who have the opportunity to visit these extraordinary environments. The potential for significant impact of scientific activities on a single vent site or a population of vent animals pales in comparison to the potential for disturbance by volcanic/tectonic events or industrial mining/harvesting activities. Nonetheless, we recognize that some scientific activities could adversely affect individual sites or impact communities more than is necessary, if research activities are not carefully planned and executed. In addition, because only a limited number of sites are currently known and scientists from a wide variety of disciplines frequently work at single locations, we recognize the potential for use conflicts among scientists, at sites where scientific activity is intense.

Aug 24, 2006