• 자원환경지질
• /
• 제28권3호
• /
• pp.199-211
• /
• 1995

The deep sea camera system could render it possible to obtain the detailed information of the nodule distribution, but difficult to estimate nodule abundance quantitatively. In order to estimate nodule abundance quantitatively from deep seabed photographs, the nodule abundance equation was derived from the box core data obtained in KODOS area(long.: $154^{\circ}{\sim}151^{\circ}W$, lat.: $9^{\circ}{\sim}12^{\circ}N$) during two survey cruises carried out in 1989 and 1990. The regression equation derived by considering extent of burial of nodule to Handa's equation compensates for the abundance error attributable to partial burial of some nodules by sediments. An average long axis and average extent of burial of nodules in photographed area are determined according to the surface textures of nodules, and nodule coverage is calculated by the image analysis method. Average nodule abundance estimated from seabed photographs by using the equation is approximately 92% of the actual average abundance in KODOS area. The measured sampling points by box core or free fall grab are in general very sparse and hence nodule abundance distribution should be interpolated and extrapolated from measured data to uncharacterized areas. The another goal of this study is to depict continuous distribution of nodule abundance in KODOS area by using PC-version of geostatistical model in which several stages are systematically proceeded. Geostatistics was used to analyse spatial structure and distribution of regionalized variable(nodule abundance) within sets of real data. In order to investigate the spatial structure of nodule abundance in KODOS area, experimental variograms were calculated and fitted to a spherical models in isotropy and anisotropy, respectively. The spherical structure models were used to map out distribution of the nodule abundance for isotropic and anisotropic models by using the kriging method. The result from anisotropic model is much more reliable than one of isotropic model. Distribution map of nodule abundance produced by PC-version of geostatistical model indicates that approximately 40% of KODOS area is considered to be promising area(nodule abundance > $5kg/m^2$) for mining in case of anisotropy.

• 자원환경지질
• /
• 제30권5호
• /
• pp.493-498
• /
• 1997

The purpose of this study is to develop geostatistical model for evaluating the abundance of deep-sea manganese nodule. The abundance data used in this study were obtained from the KODOS (Korea Deep Ocean Study) area. The variation of nodule abundance was very high within short distance, while sampling methods was very limited. As the distribution of nodule abundance showed non-gaussian, indicator simulation method was used instead of conditional simulation method and/or ordinary kriging. The abundance data were encoded into a series of indicators with 6 cutoff values. They were used to estimate the conditional probability distribution function (cpdf) of the nodule abundance at any unsampled location. The standardized indicator variogram models were obtained according to variogram analysis. This SIS method had the advantage over other traditional techniques such as the turning bands method and ordinary kriging. The estimating values by indicator conditional simulation near high abundance area were more detailed than by ordinary kriging and indicator kriging. They also showed better spatial characteristics of distribution of nodule abundance.

• 자원환경지질
• /
• 제29권4호
• /
• pp.429-437
• /
• 1996

The purpose of this study is to correct the nodule abundance of FFG (Free Fall Grab) sampler on KODOS (Korea Deep Ocean Study) area in North-East Pacific Ocean. The image analysis of sea-floor photography was carried out for correcting the abundance of nodules, and the image enhancement techniques and edge detection method were used to discriminate between nodules and sediments. The trace of nodules on sediments was detected to reduce the fractionation effect in calculating the coverage of nodules. The three methods, using the coverage of nodules, using the volume density, and using corrected volume density, were utilized for the correction of the nodule abundance. The method using the coverage of nodules was more convenient and available for the correction of nodule abundance than the other two methods. The method using the corrected volume density had the highest confidence level compared with the other methods.

• Ocean and Polar Research
• /
• 제26권2호
• /
• pp.219-230
• /
• 2004

The aims of this study are to construct database using geostatistics and Geographic Information System (GIS), and to derive the spatial relationships between manganese nodule abundance and each factor affecting nodule abundance, such as metal grade, slope, aspect, water depth, topography, and acoustic characteristics of the subbottom using the GIS and probability methods. The greater is the copper and nickel grade, the higher is the rating. The distribution pattern of nickel grade is similar to that of copper grade. The slopes are generally less than $3^{\circ}$, excluding seamounts and cliff areas. There is no increment in the rating with increasing slope. The rating is highest for slopes between 2.5 and $3.5^{\circ}$ in block B2 and between 3 and $6^{\circ}$ in block C1. The topography is classified into five groups: seamount, hill crest, hill slant, hill base or plain, and seafloor basin or valley. The ratings prove lowest for seamount and hill crest. The results of the study show a decrease in the rating with an increase in water depth in the study area. There was a poor relationship between manganese nodule abundance and the thickness of the upper transparent layer in block C1. Using GIS, it is possible to analyze a large amount of data efficiently, and to maximize the practical application, to increase specialization, and to enhance the accuracy of the analyses.

• Ocean Science Journal
• /
• 제41권3호
• /
• pp.149-161
• /
• 2006

The aims of this study are 1) to construct a database using geostatistics and Geographic Information System (GIS), and 2) to derive the spatial relationships between manganese nodule abundance and other geological factors such as metal grade, slope, water depth, topography, and acoustic characteristics of the sub-bottom. Using GIS, it is possible to analyze a large amount of data efficiently, and to maximize the practical application, to increase specialization, and to enhance the accuracy of the analyses. The greater the copper and nickel grade, the higher the rating. The distribution pattern of nickel grade is similar to that of copper grade. The slopes are generally less than $3^{\circ}$ except for seamounts and cliff areas. The rating shows no correlation with slope. The rating is highest for slopes between 2.5 and $3.5^{\circ}$ in block N1 and between 4.0 and $4.5^{\circ}$ in block N3. The topography is classified into five groups: seamount, hill crest, hill slant, hill base or plain, and seafloor basin or valley. The rating proves lowest for seamount and hill crest. Our results show that the rating increases with the water depth in the study area. Nodule abundance dose not show any significant relationship with the thickness of the upper transparent layer in the study area.

• 한국해양학회지:바다
• /
• 제13권3호
• /
• pp.280-285
• /
• 2008

자유낙하식 시료채취기(Free Fall Grab, FFG)를 이용하여 산출한 망간단괴의 부존밀도는 보정이 필요하다. 그 이유는 FFG로 망간단괴를 채취할 때 해저면에 부존되어 있는 망간단괴의 실제 양 보다 적은 양만이 채취되는 것으로 알려져 있기 때문이다. 지난 1994년과 2002년에 각각 1.29와 1.13의 망간단괴 부존밀도 보정상수가 제시된 바 있으며, 이는 주로 해저면 영상자료의 분석을 통해 이루어 졌다. 이 연구에서는 동일한 정점에서 FFG와 상자형 시료채취기(Box Corer, BC)를 이용하여 회수한 망간단괴의 부존밀도를 비교하여 기존에 제시된 망간단괴 부존밀도 보정상수와 비교하였다. 그 결과 FFG를 이용한 망간단괴의 회수율이 BC에 비하여 낮으며, 그 차이는 약 1.4배로 기존의 보정상수에 비해 훨씬 더 크게 나타났다. 따라서 향후 추가 시료 획득과 해저면 영상분석의 개선을 통해 기존의 망간단괴 부존밀도 보정식을 재산정할 필요성이 제기된다.

• 자원환경지질
• /
• 제44권6호
• /
• pp.475-483
• /
• 2011

자유낙하식 망간단괴 채취기 (FFG)는 정점의 해저면에 분포하는 망간단괴를 모두 채취하기 어렵기 때문에 망간단괴의 부존률을 평가할 때 반드시 보정해서 사용해야 한다. 북동태평양에 위치한 대한민국의 망간단괴 광구 중에서 북쪽광구의 보정상수는 이미 해저면 영상분석으로 결정되어 있다. 그러나 남쪽광구는 망간단괴가 퇴적물에 피복되어 있어서 영상분석에의한 부존률 평가에 지장을 받을 가능성이 있다. 이번 연구에서는 과거에 남쪽광구에서 FFG로 획득한 부존률 자료에 사용한 보정상수를 검증하기 위하여 2007~2009년에 상자형 시료 채취기와 FFG를 동시에 운영하여 40개의 정점자료를 획득하였다. BC와 FFG의 상관분석을 통하여 BC가 FFG에 비하여 1.43배 부존률이 크게 나타났으며, 이것은 남쪽광구에서 실제 망간단괴 분포를 평가하기 위해서는 FFG 자료에 1.43의 보정상수를 곱해서 사용해야 되는 것을 의미한다. 이번에 획득한 보정상수는 기존에 영상분석을 통해 얻은 보정상수(1.42~1.45)와 유사한 결과로서 남쪽광구에서 사용할 보정상수가 검증되었다고 판단된다.

• 지구물리
• /
• 제9권4호
• /
• pp.427-441
• /
• 2006

광역적인 망간단괴 분포상과 미세한 지형변화와의 상관관계를 해석하고 발달경향에 대한 규칙성을 지배하는 요인을 규명하는 것은 망간단괴 개발을 위한 채광등급설정에 있어서 가장 중요한 근접해저면 평가기법중의 하나이다. 본 연구에서는 망간단괴 개발을 위해 대한민국이 UN으로부터 할당받은 한국심해연구(Korea Deep Ocean Study, KODOS) 지역에서 획득된 천부지층자료와 예인형 심해영상시스템 자료를 대상으로 망간단괴 성장에 직접적으로 관련된 천부퇴적층의 분포를 파악함으로써 망간단괴의 분포를 고찰하고, 격자형 해저영상자료를 이용하여 미세 지형에서의 망간단괴 발달경향과 분포특성에 대한 공간적 해석을 실시하였다. 최상부 음파투명층의 두께와 총 부존율은 상관성이 거의 없어 보이지만, r형 및 t형 단괴와는 역의 상관관계가 뚜렷하게 나타난다. 연구지역에서 획득된 자료 분석을 통해 부존율, 산출경향, 연속성, 지형요소 등을 대비하였을 때, 4개 요소 간에는 일정한 관련성을 보이는 것으로 나타났다.

• 자원환경지질
• /
• 제29권5호
• /
• pp.575-587
• /
• 1996

The purpose of this study is to develop geostatistical methods for selection of prospective areas of polymetallic nodule deposits in KODOS (Korea Deep Ocean Study) area of the North-East Pacific Ocean. In this study $110{\times}165$ grid system was used, and each node represents the center of an estimated block of $1km{\times}1km$. The ordinary kriging was applied to SeaBeam2000 data in order to evaluate the bathymetry. A structural analysis (variogram) of the bathymetry data was carried out for constructing digital terrain model (DTM) and the maximum slopes of the bathymetry were calculated by DTM data. The above method can be used to solve the problem that is resulted from the lack of theory of a change of support model for the maximum slope of the bathymetry. The ordinary kriging and the indicator kriging were used to evaluate the nodule abundance, and the different two kriging methods were compared to evaluate the accuracy for the estimation of the nodule abundance. It has been shown that indicator kriging was better estimation tool than the ordinary kriging. The overlay map is presented for the selection of potentially minable sites by combining the two indicator maps of the nodule abundance and the maximum slope of bathymetry. This overlay map could be utilized to establish follow-up survey and to investigate the potentially minable sites in the KODOS area.

• Ocean and Polar Research
• /
• 제36권4호
• /
• pp.515-524
• /
• 2014

The Korea Institute of Ocean Science and Technology has acquired detailed biological, chemicophysical, and geological data in the northeastern Pacific through a manganese nodule program since 1983. Plenty of manganese nodules were collected to estimate the amount of resources by free-fall grab and box corer. The collected manganese nodules have been archived systematically in the rock and mineral storage section of the Library of Marine Samples (LIMS) since 2012. The LIMS provides essencial information on the stored samples including sample name, nodule type, sampling location, depth, and equipment. Although a high quality database of the information system is under construction, the samples have tagged information for manganese nodules like chemical composition, morphology, weight, size, abundance, and photograph. In this study, we attempted to provide information on the well-organized and easily accessible archived manganese nodule samples for future studies and to introduce the usefulness of the LIMS.