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By Henk van Muijen, Jan Willem de Wit

1.1 Profile IHC Holland Merwede IHC Holland Merwede is world market leader in the construction of specialist dredging equipment and large-size custom-built offshore vessels. The clients of IHC Holland Merwede include major dredging companies, oil and gas exploration groups, offshore contractors and government authorities. IHC Holland Merwede is focused on the continuous development and innovation of technology to ensure maximum performance and efficiency of its designs and constructions supplied to the dredging and offshore industries. IHC Holland Merwede has a staff of approximately 2,000 at its locations in Hardinxveld- Giessendam, Kinderdijk, Krimpen aan den IJssel, Sliedrecht, Delfgauw, Goes, Hendrik Ido Ambacht and Heusden. Besides worldwide representations, IHC Holland Merwede has branches in China, Houston (USA), India, the Middle East and Singapore. 1.2 Mission IHC Holland Merwede’s mission is to optimize value by anticipating and satisfying its client’s requirements, with efficient advanced technology solutions. The group’s aim is to be consistently at the forefront of technology development, in the business sectors in which it operates.

By S. Jeffress Williams

The topic area for this paper covers the United States portion of the northern Gulf of Mexico, extending from the Rio Grande delta east to the Florida peninsula. Declaration of an Exclusive Economic Zone in 1983 expanded Federal economic jurisdiction on the continental margins from 12 to 200 nautical miles seaward from the coast. The nation-wide area of the EEZ totals 3 million square nautical miles, with approximately 186 thousand square nautical miles in the Gulf of Mexico. In the Gulf, the continental shelf has an area of 81 thousand square nautical miles, extending to a depth of 600 ft. and having widths of 6 to 120 nautical miles. Specific areas on the shelf offer the greatest potential for containing aggregate and other hard mineral resources. The primary geomorphic features along the Gulf coast include: barrier islands, chenier plains, tidal inlets, bays and lagoons, estuaries, and deltaic headlands. These features are composed of terrigenous siliclastic sediments, except for the west Florida coast, south of 29°N latitude, which is dominated by carbonate sediments. On the shelf, the primary features are linear sand shoals and associated sand sheets, relict delta lobes and channels, and banks related to salt diapirs and coral reefs. The composition and distribution of sediments in these coastal and shelf features are determined by numerous geologic factors including: seabed topography; riverine sediment discharge; sediment dispersal patterns due to currents, waves, storms and tides; tectonics and subsidence; and repeated fluctuations in sea level.

Jan 1, 1986

By Mikhail D. Ageev

The paper concerns with some questions of Autonomous Underwater Vehicle (AUV) control system design, which allows a motion at rough undersea terrain. The AUV advantages reveal itself completely during exploration of such objects as seamounts and reefs area. These objects are characterized by steep slopes (30 degrees and above) and chaotic situated obstacles (rock debris, pinnacles, escarpments). Uses of other technical facilities for operating in such formations are difficult, dangerous or impossible. These regions take an interest due to the presence of iron-manganese crusts. Modern AUV can estimate density of mineral by means of still camera or video recorder. For this reason the vehicle has to move with the distance of 3-5 meters from seabed. Under such conditions micro- and mesorelief presents a considerable danger for AUV. The AUV can bypass underwater obstacles in the various ways. However, in any case AUV motion will be characterized by intensive maneuvering on various speed (from 0 up to 1.5 m/s), circular change of tractive force vector and, hence, a circular flow about the hull. So, AUV is equipped with the propulsion system, which provides free modes of motion. AUV control system (CS) has tri-level structure to allow a motion in a rugged seabed terrain. According to the generally accepted categorizations, CS includes execution, coordination and strategic levels. The strategic level contains the goals of AUV mission. Obstacles avoiding and route choice are realized by means of simultaneous maneuver in vertical and horizontal planes. Sonar system is used for data acquisition about obstacles. It consists of a few echo-sounders with fixed directivity pattern. The route choice algorithm operates at two lower levels of CS. Basic (?reflex?) functions of spatial motion are realized within the execution level and considered in the paper. The choice of motion modes is carried out at the coordination level of system. All accessible navigating information (the data from flight sensors and from multichannel echo-sounder systems) is used for this purpose. In addition the bypass of characteristic types of obstacles is carried out with the help of basic motion modes combination. The modeling results of bypass of various typical obstacles, and also their combinations are described in the paper.

Jan 1, 2011

By Gérald Riverin

Over the past century, exploration methods for volcanogenic massive sulphide deposits have evolved in response to a decreasing number of discoveries made by traditional surface prospecting and by ground and airborne geophysics. Statistical trends support the concept that fewer and fewer outcropping and sub-cropping VMS discoveries will be made in the future. In turn, this creates new opportunities to develop more sophisticated exploration models and techniques to explore at greater depth and to make blind discoveries. Current exploration models include various combinations of geological, geochemical and geophysical criteria which have been based on the results of land-based VMS research. The role of seafloor research in the development of these models has so far been only of a subordinate nature, perhaps due to a lack of direct involvment of the exploration industry in the seafloor research, and vice-versa for the seafloor researchers in VMS exploration. Another contributing factor is that exploration relies on exploration criteria that result from detailed geological, geochemical and geophysical studies of both footwall and hanging wall rocks, studies that are not possible in modern sea floor environments. Nevertheless, seafoor research has contributed to our understanding of the growth of sulphide mounds, the mechanism of sulphide deposition and of the chemistry of fluids involved in VMS systems. In particular, the role of structure and of tectonic setting has been clarified through observation of active seafloor hydrothermal systems. In turn, observations made in land-based VMS research has helped seafloor researchers to focus on key issues which, will eventually contribute to improved exploration models.

Jan 1, 1998

By William J. Scott

In the last two years, C-CORE has developed a new seabed sampler directed specifically at obtaining samples from hard or compacted bottoms such as are typical of marine placer deposits. Samples are required for appraisal of concentrations of saleable commodities, and for determination of levels of biological indicators in the deposits. Recently C-CORE and the University of Victoria have been comparing the performance of the Scott/C-CORE sampler with that of the Van Veen sampler often used for biological sampling. Initial trials of the Scott/C-CORE sampler in 1992 at the WestGold mining site, Nome, Alaska, were described by Jewitt et al. at the 1993 UMI. Since that time the sampler has been modified to prevent overfilling, and to limit turbulent flow of water across the top of the sampler buckets when the sampler is recovered with partly-open buckets. The modifications included shoes to prevent sampler overfill, and flexible rubber shielding over top and sides of the sampler to prevent water circulation. Samples have been taken with both samplers in two field areas, one at Pine Cove, Baie Verte, Newfoundland, and the other near Long Pond in Conception Bay on the Avalon Peninsula, Newfoundland. In each area multiple samples were taken with both sampler types, and the samples processed immediately to establish the types and quantities of marine organisms that were present. Species identification is expected to be complete by late August.

Jan 1, 1994

By William J. Scott

In the last two years, C-CORE has developed a new seabed sampler directed specifically at obtaining samples from hard or compacted bottoms such as are typical of marine placer deposits. Samples are required for appraisal of concentrations of saleable commodities, and for determination of levels of biological indicators in the deposits. Recently C-CORE and the University of Victoria have been comparing the performance of the Scott/C-CORE sampler with that of the Van Veen sampler often used for biological sampling. Initial trials of the Scott/C-CORE sampler in 1992 at the WestGold mining site, Nome, Alaska, were described by Jewitt et al. at the 1993 UMI. Since that time the sampler has been modified to prevent overfilling, and to limit turbulent flow of water across the top of the sampler buckets when the sampler is recovered with partly-open buckets. The modifications included shoes to prevent sampler overfill, and flexible rubber shielding over top and sides of the sampler to prevent water circulation. Samples have been taken with both samplers in two field areas, one at Pine Cove, Baie Verte, Newfoundland, and the other near Long Pond in Conception Bay on the Avalon Peninsula, Newfoundland. In each area multiple samples were taken with both sampler types, and the samples processed immediately to establish the types and quantities of marine organisms that were present. Species identification is expected to be complete by late August.

Jan 1, 1994

By Du Gon Lee

This study presents a model to predict fate of resuspended sediment in the development of deep-sea mineral resources including manganese nodules under Clarion-Clipperton area of the Pacific Ocean. The manganese nodules are expected to be developed near future and major research is undergoing in Korea recently concerning many aspects of the mineral resources development. One aspect is about environmental concern related to the deep-sea development, and a major environmental problem is the resuspended deep-sea sediment. In order to quantitatively analyze the resuspended sediment in the water column during the deep-sea development, particle size distribution (PSD) was considered an important factor in this research. The model developed here includes PSD and coagulation process, as well as sedimentation process. The model is one dimensional in the vertical profile, and was designed to describe the change of particle size distribution in the water column in the given vertical point. Based on the mathematical modeling, a numerical model was developed. Using the model, basic simulation was performed under representative environmental setting of the deep-sea environment. The simulation showed the dynamics of change of particle size distribution for 50 m depth of water column from the deep-sea bed, up to 10 days of simulation time. The simulation results indicate that coagulation seemed an important factor in the fate of resuspended deep-sea sediment. As a result, this research shows that the particle size distribution approach, as well as considering the coagulation process, is needed and may be effectively applied to environmental impact analysis of deep-sea resuspended sediment. Key Word: Deep-sea Mineral Resources, Resuspended Sediment, Environmental Impact, Particle Size Distribution, Coagulation, Modeling and Simulation

Jan 1, 2003

By Porter Hoagland

There has been a recent surge of interest in existing and proposed institutional mechanisms that would govern the exploration and disposal of nonfuel minerals within the U.S. ocean jurisdiction. The Minerals Management service, a bureau of the Interior Department, has begun to promulgate regulations to allow the exploration and leasing of lands for nonfuel mineral development on the outer Continental Shelf of the united States. At the same time, a bill has been introduced in the U.S. Congress that would create a new ?national seabed? and authorize the allocation of exploration licenses for marine nonfuel minerals. Because only limited efforts have been devoted to the discovery of marine nonfuels in areas beyond the territorial sea of the United States (and no production has occurred), exploration and the generation of resource information are two primary foci of these regulatory and legislative efforts. Generally, minerals exploration activities (and associated R&D on exploration and production technologies) are eligible for the same institutional incentives available for other industrial efforts, including tax preferences for research and experimentation, patent protection, small business innovation research grants, and even the new leniency in antitrust rules

Jan 1, 1988

By Ivo Dreiseitl

The interaction between nodule harvester and eupelagic sediment on the seabed is definitely one of the key aspects of mining technology for polymetallic nodules which is to be studied in details. Physical properties of sediments play major role for evaluation of protection and preservation of marine environment while strength properties of sediments will come in useful for future mining operations. Cone penetration test (CPT) used for testing in situ is one of methods for investigation strength properties of sediments. The testing apparatus for CPT consists of an instrumented cone having a tip facing down and it is mounted on special underwater equipment (rus. UGI-1). UGI-1 can determine subsurface strength down to the depth interval 0 ? 1.10 m. Special IOM geotechnical cruise was accomplished in 1989 on board R/V Academic A. Karpinski within the extra test area of about 1000 km2. Thanks to UGI-1 the IOM database recorded unique strength sediment data (cone penetration resistance) from 279 seabed points of sounding at profiles 125.6 km long. Up to 35 strength data from depth interval 0-1.1m (every 3cm) were obtained from any particular testing point. As a result 279 strength charts could be plotted (two examples in Figure 1). The cone penetration resistance values can be correlated to shear strength parameters.

Jan 1, 2011

By Michael R. Gipp

Marine Mining Inc. is currently exploring for marine alluvial gold and diamonds on a prospecting licence over a concession that covers 10,000 km2 of the continental shelf of Ghana. The boundaries of the concession extend from 0 30'W to 2 40'W, and between the shoreline and approximately the continental shelf edge north of 4 30'N. This concession extends from Kikam Beach in the west, to Senya Beraku in the east, a distance of approximately 240 km, and seaward an average of about 40 km. The concession is entirely underwater, with the exception of the estuaries of the Ankobra and Pra Rivers. Ghana has been a large source of alluvial gold, with historical production exceeding 25 million ounces. Southwestern Ghana is characterized by Precambrian rocks, which have been folded into a number of NE-SW trending synclines and anticlines. The most significant feature of the Birimian rocks is the presence of evenly spaced gold-bearing greenstone belts. They are 10-15 km wide, separated by about 90 km, separate basins filled by folded metasediments and granitoids. The rivers that enter the concession drain most of the exposed gold-bearing belts of Ghana. Given that approximately 2 km of erosion has taken place since the Mesozoic, and that gold mines on these belts boast proven reserves of over 55 million ounces, it is likely that large amounts of gold have been eroded out and carried to the sea. Coastal fractures, related to Precambrian structures reactivated during Mesozoic rifting, are responsible for the physiography of the coastal area, which consists of high-relief horsts separated by grabens that have been occupied and infilled by rivers or by finer sediments during times of elevated sea level. These fractures were loci of gold mineralization during the Precambrian, and are the source of alluvial gold in rivers confined by them.

Jan 1, 1998

By Alexander Malahoff

The summit of L_ihi submarine volcano changed dramatically after seismic activity beneath L_ihi during the month of August 1996. Bathymetric re-surveys of the L_ihi edifice using SeaBeam, Simrad and deep-towed Reson-Focus multibeam systems showed the presence of new north-south striking fissures, normal faults and a new pit crater located at the site of a former 300-meter high volcanic cone. Comparisons between the pre-1996 SeaBeam data and the new bathymetry show a net loss of about 100 million cubic meters of rock volume on the summit. This loss is localized at a new pit crater -- the 300-meter deep by 1,300-meter wide Pele's Pit. Submersible observations with Pisces V show the northern edge of Pele's Pit to be bounded by a normal fault located north of the site of the former Pele's Vents cone that has disappeared into the new pit crater. A new hydrothermal field, the Ikaika Vents, extending from a water depth of 1,311 meters to 1,287 meters has formed at the northeastern edge of the floor of Pele's Pit. Submersible observations of these new Ikaika Vents during September 1996 showed vigorous venting at the site with extensive white-colored bacterial mats hanging off the rock face above the vents. Follow-up mapping and sampling of the vent sites during August 1997 showed vent temperatures of up to 198°C, dense populations of vent shrimps around the vents and a centimeters-thick veneer of fine-grained polymetallic sulfide mineralization along the rock walls above individual vents. The mineralogy of the sulfides shows a barite, chalcopyrite, sphalerite, and pyrite composition.

Jan 1, 1998

By James C. Barker

Concern over the availability of domestic critical and strategic mineral supplies has led the Bureau of Mines to evaluate the reserve development potential of alternative sources in Alaska. Near the village of Platinum, on the southwest Alaska coast, the Red Mountain concentrically zoned ultramafic complex is a source of onshore alluvial placers containing platinum-group-metals (PGM). It has long been suggested that valuable placers may also underlie the shallow coastal waters of the Bering Sea. A direct correlation of placer PGM and chromium to ultramafic rocks in the area was studied by the Bureau and the extent of the complex was mapped. Magnetometer and gravity data and geological studies suggest the complex is a large lensoidal body trending several kilometers offshore to the southwest with a probable steep southeasterly dip. Multiple Pleistocene glaciations and marine transgressions have eroded the western and southwestern portion of the complex. Sediments containing PGM, chromium, and associated gold (largely derived from glacial till) have been transported northward along the advancing coastline by littoral currents. Beyond the breaker zone, these sediments are generally buried by recently winnowed sand and gravel transported by strong longshore tidal currents. There is also evidence that paleoplacer channels underlie the marine sediments.

Jan 1, 1986

By Mikhail D. Ageev

The paper concerns with some questions of Autonomous Underwater Vehicle (AUV) control system design, which allows a motion at rough undersea terrain. The AUV advantages reveal itself completely during exploration of such objects as seamounts and reefs area. These objects are characterized by steep slopes (30 degrees and above) and chaotic situated obstacles (rock debris, pinnacles, escarpments). Uses of other technical facilities for operating in such formations are difficult, dangerous or impossible. These regions take an interest due to the presence of iron-manganese crusts. Modern AUV can estimate density of mineral by means of still camera or video recorder. For this reason the vehicle has to move with the distance of 3-5 meters from seabed. Under such conditions micro- and mesorelief presents a considerable danger for AUV. The AUV can bypass underwater obstacles in the various ways. However, in any case AUV motion will be characterized by intensive maneuvering on various speeds (from 0 up to 1.5 m/s), circular change of tractive force vector and, hence, a circular flow about the hull. So, AUV is equipped with the propulsion system, which provides free modes of motion.

Jan 1, 2003

By G. B. Carpenter

The United Nations Law of the Sea (LOS) Convention includes provisions (Article 76) for establishing the outer limits of a coastal State's continental shelf and for denoting the seaward extent of sovereign rights over natural resources. Determination of a coastal State's continental margin, according to Article 76, must consider eight factors: 1. The territorial sea baseline 2. The 2,500-meter isobath 3. The foot of the continental slope 4. A line 200 nautical miles seaward of the territorial sea baseline 5. A line seaward of the foot of the continental slope connecting the points where sediment thickness divided by distance to the foot of the slope equals .01 6. A line 60 nautical miles seaward of the foot of the continental slope 7. A line 100 nautical miles seaward of the 2,500-meter isobath 8. A line 350 nautical miles seaward of the territorial sea baseline Figure 1 shows the preliminary limits for each of the Article 76-based definitions for a portion of the U.S. Atlantic continental shelf. The additional areas gained beyond the 200- nautical mile Exclusive Economic Zone (EEZ) are highlighted. The first three factors are baselines from which the distance provisions of Article 76 are measured. Factors 4-8 are distance- from-baseline provisions for establishing the continental shelf limits. Factor 5, also known as the Depth of Sediment Limit or "Irish Formula", was calculated using sediment thickness data from seismic linesand isopach maps. All other factors were determined from digital hydrographic data. The Depth of Sediment Limit is the most advantageous method for the area shown in Figure 1. It is especially useful for introverted coastlines such as the Georgia Embayment and New York Bight areas. The 200-mile line is advantageous for protruding coasts such as those off major capes, e.g., Cape Hatteras. The 2,500-meter isobath plus 100-mile line gains

Jan 1, 1995

By Lisa Koch, Eleanor Martin

"Each underwater mining project is different. However, most have one thing in common: To be successful. We will draw on our experience advising hundreds of international clients each year on mining, offshore oil & gas and shipping matters to highlight some legal, commercial and practical issues to consider when structuring underwater mining projects. We will look at new ways of allocating risks and rewards in order to obtain much needed investment for underwater mining projects to commence both the exploration and exploitation phase.HighlightsRisk profileWe will look at a typical underwater mining project from the viewpoint of an investor and highlight some of the perceived risks, and potential mitigants.Contractual structureWe will analyse how the mining industry and oil & gas service industry have responded to low commodity prices to examine innovate contractual arrangements with suppliers and stakeholders, and how they can be tailored to the underwater mining industry. FinancingWe will explore some potential financing structures which could be relevant to the underwater mining industry."

Jan 1, 2017

By Alan Foley

The Portable Remote Operated Drill was developed in Sydney, Australia in the 1990’s. The device is a platform for many in-situ seabed sampling and coring tasks. The range of tools developed for use in PROD’s magazine now includes gas detectors, vane testers, penetrometers and corers. This paper presents aspects of the soils testing undertaken in deepwater since 2005, focusing on testing of methane hydrates and reefal accumulations. The varied selection of tools carried in PROD’s magazines allow the unit to perform several functions from the seafloor in one deployment.

Sep 24, 2006

By Kurt Aasly, Przemyslaw B. Kowalczuk, Rolf Arne Kleiv

Seafloor massive sulphides (SMS) can serve as a potential resource of metals such as Cu, Zn, Au and Ag. SMS rock samples from the Loki’s Castle area at the Arctic Mid-Ocean Ridge are comprised of sulphide bearing minerals such as pyrite, chalcopyrite, isocubanite, galena, sphalerite, whereas the gangue consists mainly of barite and silica. Sphalerite, chalcopyrite and isocubanite show complex intergrowth textures on the nano- to microscale. Various mineral processing tests were conducted in order to recover copper, zinc and silver. It was shown that sensor-based sorting can be efficiently used for preconcentration of SMS rock samples. A significant amount of waste (i.e. barite and silica) was removed in the preconcentration stage with very low losses of copper and zinc to the waste fraction. The upgraded samples were sent to the next processing stages. The results showed that the complex mineralogy of the SMS material provided challenges to conventional mineral processing methods. Hydrometallurgical processing was applied as an alternative method for extraction of metals from SMS. Leaching experiments were conducted using solutions of different lixiviants, and it was shown that leaching of SMS together with manganese nodules would facilitate efficient recovery of metals from these resources.

Jan 1, 2018

By J. V. R. Prasada Rao

India is dependent for 60% of its annual requirement of copper and the entire quantity of nickel and cobalt on imports from outside the country. Land-based resources are either too meager or of too low a concentration for economic exploitation. This has prompted the country to look to deep seabed re- sources for meeting its rising demand for these metals. The Ocean Policy of the Government of India announced in 1982 talks about the need to map and assess the availability of minerals in the deep sea and to develop necessary technologies for exploration and exploitation of seabed minerals. To be self-reliant such technologies would have to be largely developed, tested and operated indigenously. The adoption of the Law of the Sea Convention in 1982 gave a fillip to India's desire to get into the field of deep seabed mining. India applied for recognition as a Pioneer Investor in Ocean Mining in 1983 and received allotment of a mine site of 150,000 km2 in the Central Indian Ocean in August 1987. Simultaneously, the Government has taken up a programme of development of technologies for exploration of the mine site for resource assessment, environmental monitoring also to meet the commitments like relinquishment of 50% of the area to the Preparatory Commission. Technologies for exploitation of these seabed resource like the mining system, transportation and extractive metallurgy have also been taken up for development in various research institutes largely in the government sector. While India's objective in the long term is to meet the shortage of copper, nickel, cobalt and manganese by the turn of the century, in the short term, the programme aims at application of the seabed mining technologies to meet the immediate needs of the country such as: a. Exploration for oil and natural gas. b. Exploration and exploitation of placer minerals and other deposits at shallow depth in India's EEZ.

Jan 1, 1994

By Huaiyang Zhou

It has been long known that manganese nodules occur more or less in some part of marginal seas in West Pacific Ocean. On the other hand, it is difficult to understand their distribution and the genesis as those nodule samples were collected mostly by dredge from the deep basins generally has much higher sedimentation rate than the open ocean. For example, the sedimentation rate in the South China Sea is about three orders of magnitudes than that in region of the Clarion-Clipperton Fracture Zone. In June of 2013, a small seamount (named as Jiaolong Seamount), consisting of southern part and northern part with a distance of about 3 km each other, was visited by DSV Jiaolong/RV XiangYangHong 9. It is discovered that abundant manganese nodules exist only on the surface sediment in the southern part with a water depth of about 3800 m to 3300m, on the platforms nearby an obvious crater where volcanic rocks exposed on the wall. There are no any nodules be observed on the sediment in the northern part of the seamount (about 100 m deeper than the southern part) and surrounding deep basin (approximately 4000 m in water depth). It is speculated that a source of core for manganese nodule and a dynamic sedimentation environment, are two major governors for the growth and distribution of manganese nodule in the marginal seas.

Sep 14, 2011

By Will Roberts, M. E. Williamson

After verification of methodology and testing of prototype systems during 2005/06, Nautilus Minerals expanded their Papua New Guinea (PNG) operations to a full commercial exploration program in 2007. Included was the deployment of sensors and survey systems to locate, characterize and verify massive sulfide deposits with potential as mine sites within the tenements held by Nautilus in PNG. This presentation discusses some of the gear developed and operated during the 2007 PNG investigation.