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By Luc Rombouts

The resources and reserves calculation of marine diamond deposits should be based on a systematic sampling grid. The distribution of the sample grade results tends to be very skew and has a large variance. A bias is easily introduced due to the fact that the grade distribution of the samples is very different from the grades of the area of influence. The temptation is always there to extrapolate the highest grade samples simply to their area of influence. If this is done, the higher grade areas will be systematically overestimated, while the lower grade areas will be underestimated. Such a bias should surely be avoided by weighing the sample grades in such a way with their neighbours, so that the estimated grades have a similar distribution as the grades of the blocks. The grade distribution of small mining blocks tend to be lognormal-like. If the coefficient of variation is known, i.e. the standard deviation divided by the mean, then the grade distribution of the small mining blocks is relatively well-defined. The distribution of the diamonds within the deposits can be simulated, based on the histogram of the sample results and on the semivariogram. The diamonds tend to cluster in trapsites. From the semivariogram and the histogram, the average size and spacing between trapsites, and the grade distribution within the trapsites, can be calculated using the model of the General Family of Discrete Distributions. Using such a simulated deposit, the grade distribution for different block sizes can be obtained. The grade distributions become more lognormal-like with increasing block sizes, as the trapsite effect is reduced.

Jan 1, 1998

By Akira Usui

The details in small-scale variability of the geological occurrence and chemical composition of ferromanganese crusts are not yet well understood, although the northwestern Pacific seamounts are believed to be among the most promising areas for rare metal resources. Our belief is that geological observations and geochemical analyses are still insufficient for economic evaluation or for discussion of depositional processes and environments. Our team, composed of geologists, mineralogists, geochemists, physical engineers, and microbiologists has attempted to utilize an ROV for in-situ measurement and for sampling of undisturbed and uncontaminated ferromanganese crusts at three typical seamounts in the NW Pacific near the Japanese Exclusive Economic Zone. The first ROV geological survey of ferromanganese crusts was successfully completed, and the ROV proved to be the most powerful, efficient and elegant method to date. The collected samples (more than total 1 ton of crusts, at more than 100 sites along a total of approximately 10 km of survey lines) were most suitable to analyze water-depth dependency and secular variation of their composition. The intact surfaces of crusts, collected without the usual abrasion caused by dredging, were also valuable for microbial study of Mn oxidizing bacteria. The ROV sampling devices, however, can be improved with further sophisticated drills or rock saw blades in the future.

Jan 1, 2011

By Brian D. Bornhold

A comprehensive multi-disciplinary marine geological survey of northwestern Graham Island, Queen Charlotte Islands, British Columbia, Canada was conducted by Offshore Survey and Positioning Services Ltd. of Vancouver, B.C. on behalf of the Geological Survey of Canada; Energy, Mines & Resources Canada, Pacific Geoscience Centre, Sidney, B.C. Canada during October 1984 and July 1985. The aim of the survey was to map both the surficial geology and geomorphology in order to identify and evaluate the nature of the nearshore sedimentation and recent tectonics including stability (slumps and scarps) seafloor faults (frequency and displacements) and both the classification and consistency of soil type boundaries and properties. Data was acquired by utilizing conventional indirect applied marine geophysical techniques including side scan sonar, precision echo sounding and complimentary soil sampling. During October 1984 a total of 320 line kilometres of data including 180 soil samples were acquired. During July 1985 a total of 300 line kilometres of data were acquired including 150 soil samples.

Jan 1, 1985

By Paul C. Rusanowski

Mining is a waste intensive industry, oftentimes producing hundreds of kilograms of waste rock and tailings for every gram of metal recovered. Disposal of mine tailings is a major concern in most mining operations. In Southeast Alaska the steep terrain and high seismic hazard province limits cost effective opportunities for land disposal of tailings. The lack of infrastructure and long travel distances generally limits secondary utilization of tailings, as well. Since the mines are located close to tidewater, submarine tailings disposal is an attractive option for tailings management. At the present time the EPA will not issue a permit that authorized marine tailings disposal from any mining process that includes flotation technology. Upland disposal is the "Best available technology" and must be used. Consideration of submarine disposal is generally precluded because the tailings are contaminated with fluids from the flotation process. However, when developing technological solutions to minimize environmental disturbance, destruction, pollution, and risk, submarine tailings disposal deserves another evaluation. In Southeast Alaska it may be the "Best available technology" based on an assessment of all issues and concerns in these mining projects.

Jan 1, 1991

By Jung-Hoon Kang

Present study was stemmed from the survey associated with deep-sea mining in the KODOS area between Clarion Fracture Zone and Clipperton Fracture Zone located in the North Pacific Ocean. The study area, which is located in the southeastern part of North Pacific gyre, is oligotrophic waters with low nutrients and chl-a concentrations below 1µg/l (MOMAF, 1996). This area is also characterized by divergence at 8°N and convergence at 6°N, which moved northward or southward in the range of a few kilometers with seasonal and climate changes. If the waste materials related to deep-sea mining are intruded into the surface waters continuously, unexpected effects to water column ecosystem are anticipated negatively. In order to assess the impact on the planktonic ecosystem, natural variation need to be distinguished from anthropogenically induced variation in terms of the abundance and species composition of plankton. In this study, mesoscale variation of zooplankton community was reported in relation to the physical conditions in the northeastern Pacific during 1998 and 1999. Temperature and salinity were determined using a CTD from surface to 200m depth in July 3-20, 1998 and in June 22-July 1, 1999. Zooplankton samples were collected from two different depths (0-50m, 50-200m) by vertical towing using an opening-closing net (100cm diameter and 300 µm mesh size). The samplings were carried out at every one degree between 5° and 12°N (1998), between 5° and 11°N (1999) along the meridional lines of 131°30´ W. The net was lowered to the depth of interest from a stationary research vessel and towed upward to collect zooplankton at a speed of 25~30 m per minute. Zooplankton samples were transferred to 1-l sampling bottles and immediately fixed with neutralized formalin into the final concentration of 5%. Considering the characteristics of zooplankton such as diurnal vertical migration, all samplings were done during the nighttime. The volume filtered by the net was calculated from the readings of flow meter (Hydro-Bios Model 438-115). Zooplankton were identified to the genus level and enumerated under a microscope. The abundance of zooplankton at each station was expressed as the numbers/100 m3.

Jan 1, 2003

By Andrea Koschinsky, Luise Heinrich, Stefan Gößling-Reisemann

"Germany, like several other countries, has entered a contract with the International Seabed Authority (ISA) to explore the prospects of commercial manganese nodule mining in the Clarion-Clipperton Zone (CCZ). Ensuring a maximally sustainable deep-sea mining operation requires a thorough understanding of the environmental impacts associated with every step of the mining process from the extraction of the nodules at the seafloor to the refinery on land. Against this background, the project presented here applies a combination of scenario-building and life cycle assessment (LCA) to assess and evaluate the sustainability performance of the individual process steps as well as the entire mining operation.Life cycle assessment (LCA) is a comprehensive methodological framework that allows the identification and quantification of impacts occurring during a products life-cycle, as well as the analysis and evaluation of their contribution to pre-defined impact categories, such as climate change, acidification and toxicity (Rebitzer et al., 2004). Until now, LCAs with a focus on raw material extraction have almost exclusively been applied to terrestrial processes. Noteworthy exceptions are offshore drilling, offshore wind farms and ocean fishing. Hence, the first part of the project is to investigate in how far LCA can be applied to deep-sea settings and if and in what way it could be adapted to be used in a deep-sea mining context."

Jan 1, 2017

By Grigori Abramov

Borehole Mining (BHM) is a remotely operated underground and underwater method of extracting (mining) mineral resources by high-pressure water jets. It can be carried-out from the land surface, open pit floor, underground mine and floating platform or vessel. The method is currently in use in mining and exploration of such natural resources and industrial materials as: uranium, iron ore, quartz sand, gravel, coal, poly-metallic ores, phosphate, gold, diamonds, rare earths, amber and several more. Yet another application of Borehole mining technology is construction of subsurface collectors, ground walls and storage for compressed or liquefied gases, oil and other products.

By Christian Müller, Hermann-Rudolf Kudrass, Christian Reichert

Recent studies estimate the depletion mid-point (dmp) for conventional natural gas to be reached around year 2022, and for conventional oil to be reached around year 2017. These numbers are based on simplified assumptions of unchanged demand and do not include increasing reserves from discovery of new fields and also do not include a shifting of resources to reserves e.g. due to an increasing oil price (Gerling et al., 2005). Anyhow, these prospects require conventional hydrocarbons to be substituted in the near future.

Aug 24, 2006

By Alexander Malahoff

Field observations and sampling of land-based and submarine hydrothermal and geothermal sites show a definite link between the geological setting, fluid geochemistry and specialized assemblages of microorganisms found at these settings. Three initial sites have been chosen as a basis for these studies. The first site is located on hydrothermal vents in pit craters on the submarine volcano Lo?ihi (Hawai?i) at a water depth of 1,300 meters. The second site is within the geothermally active vents, ponds and lakes of the Taupo Volcanic Zone of New Zealand. The third site extends along the chain of volcanically and hydrothermally active volcanoes of the Kermadec-Tonga arc and back-arc system. To focus our work in New Zealand, a geomicrobiology field and experimental center has been established in Wairakei, New Zealand, with the relevant genomics, proteomic and bioinformatics work being conducted at the University of Hawaii. As part of a partnership between the University of Hawai?i, the Institute of Geological & Nuclear Sciences (GNS) and Victoria University of Wellington, a new interdisciplinary graduate course in geomicrobiology will be taught at Victoria University beginning next year. Since mineral-microbial interactions have been occurring for the past few billion years and these interactions have led to where one generates the other, a metal-bacteria research program has been initiated at GNS using arsenic-gold and other metal-bacterial interaction processes as a research objective. In this research program, we have completed the full genome of a new species of marine bacterium Idiomarina loihiensis from the Lo?ihi hydrothermal vents and identified specialized microorganisms living in pH 0.3 geothermal vent waters of White Island, New Zealand. The multidisciplinary approach to study the process of accumulation of metals in the hydrothermal systems clearly shows the path of how bacterial-mineral interaction can precipitate metal deposits. These studies will lead to new avenues for biomining, bioremediation and the understanding of the origins of life.

Jan 1, 2004

By John Halkyard

Deep ocean mining is experiencing a rebirth following many years of low levels of activity. Large scale mining is being projected as just over the horizon. A lot has been made of the advances in deep water oil and gas developments over the last thirty years, and how this technology is directly applicable to ocean mining. The authors present their views on this from a perspective of a legacy of participating in the development of manganese nodule mining systems in the 1970s, followed by thirty years in the deepwater oil & gas arena. While it is true that great advances have been made in subsea technology, the differences between mining and oil and gas recovery should not be diminished. Fundamentally, oil and gas are stored in compact reservoirs under pressure. Any intervention leads to flow of the material up a pipe to the surface. The seabed hard minerals are stuck in place, either adhering to sticky pelagic sediment (nodules) or bonded together as hard rock (massive sulfides). The minerals require complex machinery in order to be extracted, sized, concentrated and lifted to the surface. Once at the surface the ore must be dewatered, de-fined and transferred to shore for processing. The overflow from this dewatered product must return to the sea in an environmentally satisfactory manner. These steps involve technology unique to mining that has to be addressed in a methodical fashion before commercial mining systems can be designed. The presentation will discuss the critical technical challenges of deepsea mining and thoughts on different routes to commercialization. The program will address the critical technical challenges, as perceived by the authors, and steps required to address them. Alternate development programs will be discussed focusing on nodules and sulfide. Keywords: manganese nodules, polymetallic sulfides, ocean mining

Jan 1, 2011

By Olav Rune Godø

We present a science-based infrastructure for continuous online monitoring of the ocean interior including benthic, pelagic and the demersal habitats. It will reduce expensive ship based monitoring costs associated to offshore and coastal industries. We combine established Norwegian cabled observatory technology and German mobile seafloor robotic technology and thus supports the transition from local to spatial ecological monitoring. Both technologies are developed through science - industry partnerships. In Norway, the Institute of Marine Research has worked with Statoil ASA and Metas AS to install and operate the LoVe cabled observatory. The German technology is developed by iSeaMC and Kraken Robotik, two spinoff enterprises of the Helmholtz Alliance “ROBEX”. GEOMAR has recently developed a lander-based deep-sea crawler that operates autonomously based on the original iSeaMC crawler system using the Kraken Autonomy. Combined with the Spanish image processing and modelling expertise in the SME Deusto Sistemas SA the consortium hosts the capacity to establishing a complete semi-autonomous real-time monitoring system. Merging of existing technologies into one operational autonomous product through the unique competence of partners’ support international ambitions (e.g. Blue Growth, GES, Horizon 2020), and renew monitoring that assess impact of human use of the marine environment. The consortium has been invited to contribute to technology/science programs for the Yellow Sea and for European mining and offshore decommissioning industries, which demonstrates the leading role of our consortium. The project is funded through the EU Martera program and started in June this year.

Jan 1, 2018

By S. Rajendran

Gas Hydrates (Methane Hydrates) are solid, ice ? like substances composed of water and natural gas. They occur naturally in areas of the world where methane and water can combine at appropriate conditions of temperature and pressure and are found in the ocean bottom sediments and in some permafrost areas. Besides temperature and pressure, factors like bathymetry, sediment thickness, sedimentation rates, and total organic carbon content (TOC) also control gas hydrate formation in the sea. The stability of gas hydrates depends on the critical high pressure ? low temperature combination (0-17 bars, 0-25ºC), which in turn dependent on the mix of gases from which the mineral is formed. As the critical parameters can be altered by deposition, erosion or slumping of sediments, formation or melting of ice cover, rise and fall of sea level and sudden temperature changes induced by tectonic activities, current flows or volcanisms, the gas hydrates tend to be very unstable. It is becoming increasingly evident that naturally occurring gas hydrates are significant component of the shallow geosphere and are of societal concern in at least three major ways: as an energy resource, a geologic hazard and a major contributor for climatic changes.

Jan 1, 2010

By Alexander Malahoff

The study of why and how life survives in the Extreme environment is a major frontier of science today. Extremophiles are organisms that require extreme environment including high temperature, pH, pressure and salt concentration, or low temperature, pH, nutrient concentration, or water availability. Their common habitats are geothermal vents, pools, lakes and craters of active volcanic regions, such as those of New Zealand, Japan, Kamchatka, Yellowstone USA or the hydrothermal vents of the ocean ridges and submarine volcanoes. These settings are accessible by foot, boat, helicopter, or submersibles. This presentation examines the geology, chemistry of geothermal sites of New Zealand, including the active volcano, White Island, Yellowstone, the submarine volcano Loihi in Hawaii, and sections of the mid-ocean ridges. Designing process and construction of Extremophilic sampling and bioreactor systems used in the study of Extremophiles will be discussed. The driving force behind the research of extremophiles is not only the fundamental science, but also biotechnological potential associated with these microorganisms and their cellular products. The University of Hawaii?s Marine Bioproducts and Engineering Center (MarBEC) is laying the foundations for such new industries.

Jan 1, 2001

By S. Kim Juniper

Ocean observatory technologies permit uninterrupted, real-time observation of dynamic seafloor environments such as gas hydrate deposits and hydrothermal vent fields that are of both scientific and economic interest. Such observations enable new discoveries of linkages between physical, chemical and biological processes and could permit continuous monitoring of environmental variables during mining operations. Ocean Networks Canada operates the NEPTUNE and VENUS cabled observatories in the Northeast Pacific Ocean. The offshore NEPTUNE observatory supports instruments at two gas hydrate sites on the continental margin off Vancouver Island, and in the hydrothermal vent fields of the Endeavour segment of the Juan de Fuca Ridge. The primary focus of the gas hydrate field observations is to understand the dynamics of the growth and stability of outcropping and sub-seafloor hydrate deposits. Outcropping hydrates at 840 m depth in Barkley Canyon have been monitored for the past 3 years with a mobile instrument platform known as Wally, which is operated over the Internet by a research group in Germany. This tracked vehicle carries standard oceanographic sensors, acoustic current metres, cameras and methane sensors. Data indicate a relationship between degassing of hydrates and tidal currents. In 2012-2013 two high-resolution sonar towers were added to the hydrate field to provide precision tracking of Wally and to monitor volume changes in the outcropping hydrate mounds. A large subsurface hydrate deposit occurs at the Clayoquot Slope site, where bottom depth is 1260 metres. Monitoring instrumentation is currently being established at this location. Gas bubble release from this deposit is being monitored by a sector scanning sonar mounted on a

Sep 14, 2011

By M. F. Dibble

The technology available for mining of underwater mineral resources such as placers and phosphorite, typically occurring with variable amounts of overburden, has remained largely unchanged for decades. The traditional bucket ladder dredge with maximum digging depth of 48 m and monthly capacities about 500,000 m3 still reins as the only heavy duty mining system capable of working the tough materials characteristic of heavy metal placers. Attempts at adapting the bucket wheel cutter-suction dredge to these severe conditions have not yet been successful except in moving small volumes from shallow depths. High capital cost (20-30 million U.S. dollars), high cost of overburden removable, and turbidity generation for the bucket ladder are often significant negative factors in mining operations where this system remains the only viable alternative. The Japanese continue to advance the technology of their submersible dredge pump system powered by specially adapted, direct drive electric motors. Present systems are designed primarily for working surficial deposits of aggregate to depths as great as 90 meters, the pump suspended by cable from a surface vessel with an eductor pipe leading from the pump to the vessel. Such a system may prove adaptable to a variety of surficial deposits including phosphorite, shell and heavy minerals in addition to aggregate. However promising for the exploitation of surficial deposits, little advantage can be expected for the deeper buried and more difficult deposits.

Jan 1, 1986

By Frank Manheim

The purpose of this presentation is to review the history of offshore non- fisheries resource development since World War II, as an introduction to a planned symposium on offshore resources scheduled for the 1996 UMI Conference. After World War II the United States became the leader in offshore oil and gas production, deep ocean drilling technologies, offshore terminals, platforms and production systems, and natural gas recovery and transport. Wartime skills in acoustic profiling and antisubmarine warfare were transferred into commercially important geophysical exploration techniques. The application of ocean drilling and geophysical techniques permitted the recognition and elucidation of plate tectonics patterns, development of seafloor spreading theory, and the transformation of our knowledge of seabed and subseabed strata. After John Mero's studies and recommendations for developing marine manganese nodules in the late 1950's interest in nonfuel minerals grew rapidly. The formation of international deep sea mining consortia in the 1960's was accompanied by a flurry of ocean engineering development, minerals prospecting and associated environmental studies The Santa Barbara Oil Spill of 1969 resulted in a moratorium on both offshore energy and minerals leasing by the Depart- ment Interior, and catalyzed the development of new Federal legislation in 1972. In 1973 the offshore energy moratorium was lifted in response to the Arab oil embargo, and offshore energy activities surged for a time. Minerals were reopened to leasing following President Reagan's 1983 executive order implementing a 200 mile EEZ. Although interest was spurred by

Jan 1, 1995

By S. W. Chang, James R. Hein, S-R. Lee, A. Zondervan, H. Choi

"Nine Fe-Mn nodules from the extensive nodule field in the east of Campbell Plateau of southwest Pacific Ocean beneath the Deep Western Boundary Current (DWBC) and Antarctic Circumpolar Current (ACC) were analyzed for the 10Be/9Be dating by AMS (Accelerator Mass Spectroscopy) at IGNS, New Zealand.Several types of nodule morphology were identified including distinctive discoidal forms with overgrowths resulting possibly from overcrowding and partial sediment burial. Five principal nodule facies were also recognized by location and occurrence (Fig. 1) (Wright et al., 2005). Fe-Mn nodules show various concentric internal growth textures, such as, cuspates, large parabolic cuspates, pseudo-columnar, columnar, globular, and laminated, which vary even in a nodule with hydrogenetic, early diagenetic, or mixed origin. Each texture shows micro-textural varieties and different mineralogy and/or chemistry. The genesis of each internal texture was indicated by the REE patterns, the mineralogy of Mnoxides, and the Mn/Fe ratios."

Jan 1, 2017

By David Huber, John Halkyard

Deep Reach Technology, Inc. recently completed a multi-year cooperative research project for the U S Army Research Laboratory for the purposes of investigating recovery of rare earth elements from the seabed. This research led to the discovery of a potentially economical deposit in the Exclusive Economic Zone of the Cook Islands. In order to further develop this resource, Ocean Minerals LLC (OML) was formed in 2016 to explore the development of a deep-sea mining project to recover rare earth elements and scandium from the upper 10m of sediment in promising areas of the Cook Islands Exclusive Economic Zone. OML and the Cook Islands Investment Corporation signed an Agreement in 2016 giving OML exclusive rights to explore a 12000 sq km area and option rights over an additional 48,000 sq km. This poster presents the current status and activities related to this project.

Jan 1, 2017

Ancient volcanogenic Cu-Zn-Pb-Ag-Au massive sulfide ores commonly have associated with them along strike and in the immediate hanging wall a distinctive sediment that is thin, usually cherty and metal enriched, and generally referred to as an "exhalite horizon" or "tuffaceous exhalite". Typical examplks include the 13 Ma tetsusekiei of the Kuroko deposits of Japan (Kalogeropoulos and Scott, 1983, Econ. Geol.) and the 2700 Ma contact tuffs of Noranda, Canada (Kalogeropoulos and Scott, 1989, Can. J. Earth Sci.) and Key Tuffite of Mattagami, Canada (Liaghat and McLean, 1992, Explor. Min. Geol.). Attempts to use trace element distributions as lithogeochemical guides to ore have been largely unsuccessful. Exhalites have been considered to be the products of seafloor hydrothermal activity that is peripheral to the main ore-producing vents. However, large actively-forming polyrnetallic sulfide deposits at the Explorer mid-ocean basalt spreading ridge (1 850 m depth) in the NE Pacific and the eastern Manus back-arc dacitic spreading center (1650 m depth) in the western Pacific have demonstrated that the exhalite horizons are more likely produced by fallout of particulates from the main hydrothermal plume. In a typical hydrothermal plume, grains of >27 µm represent up to 97% of the mass (although only 2% of the population) of the particulates and are calculated by Stokes equations to fall from the plume to the seafloor within a few krn of their source. The particles are primarily composed of anhydrite, barite, amorphous silica, iron oxyhydroxides and metal sulfides and oxides. Plumes are subject to bottom currents which push them in preferred directions, just like smoke plumes in the atmosphere are subject to the vagaries of wind direction. Bottom currents in the deep ocean can be 50 m/min or

Jan 1, 1993

By R. W. Nesbitt

The TAG and Broken Spur hydrothermal mounds are located on the Mid Atlantic Ridge (MAR) at 260N and 290N (respectively). Both were initially discovered by exploratory work from surface vessels and both have since been investigated by submersibles. The discovery of TAG resulted from a NOAA Trans-Atlantic Geotraverse (Rona et al. 1975) which fortuitously sampled low temperature materials on the east wall of the MAR rift valley and follow up operations (Rona et al. 1986) located the high temperature (365°C) mound some 5km to the west. In 1994, ODP deep sea drilling (Leg 158) at over 3,500 metres of water recovered core to a depth of 150 m below surface (Herzig et al. 1998) and for the first time allowed a geological interpretation of an active mound. The Broken Spur mound was accidentally discovered in 1993 when sulphide fragments were observed on a deep-sea towed camera system (Murton 1993). Later that year, exploratory submersible dives by Alvin located the hydrothermal field and the area was again explored by submersible in 1994 and 1997. Despite the amount of work carried out, our geological understanding of the MAR mounds is limited. Much effort has gone into measuring fluid chemistry whilst practical difficulties have inhibited good geological mapping of the sulphide areas. It is clear from both TAG and Broken Spur that the mounds are not necessarily located in the areas of highest heat potential. Indeed, TAG is some 2 km from the rift valley axis and has been operational for several tens of thousands of years. Hence, heat availability is not a major consideration and the most obvious control is a structural one. Mapping on Broken Spur indicates a series of isolated vent-sulphide areas, concentrated around a minor graben. Their distribution, size and nature all indicate that they are residual parts of a much larger sulphide body which was at least the size of the present TAG field. The evidence is for a cyclical pattern of mound growth -mass wasting? rejuvenation and the Broken Spur mound appears to be in the rejuvenation stage of the cycle. Mound cyclicity must be related to the supply of hot water which itself is a function of the connectivity of fracture systems. Hence, we return to the theme that the major controls in mound development are structural ones.

Jan 1, 1998