Abstract
Direct seafloor sampling using, e.g., box corers is insufficient to obtain an acceptable accuracy of nodule resource estimates in small parts of potential deposits. In order to increase the reliability of the estimates, it was rational to use the results of photographic surveys of the seafloor. However, the estimation of nodule abundance based on seafloor photographs is associated with a number of problems and limitations. The main goal of the study was a statistical analysis of the role and interrelationships of selected factors affecting the accuracy of nodule abundance assessment based on seafloor photographs from the H22 exploration block located in the Interoceanmetal Joint Organization (IOM) area in the Pacific. A statistically significant, but only moderately strong, correlation was found between the abundance of nodules and seafloor nodule coverage (quantitative variables), the nodule abundance and genetic type of nodules (ordinal variable estimated visually from photos), and between seafloor coverage with nodules and sediment coverage of nodules (ordinal variable estimated visually from photos). It was suggested that the nodule abundance could be effectively and more accurately predicted using a general linear model that includes both quantitative and ordinal variables.
Highlights
The determination of the percentage of seafloor nodule coverage in the photographs treated as soft data should, despite their lower reliability, result in a noticeable increase in the accuracy of the estimation of nodule resources, especially in small parts of the deposit
There should be a strong correlation between the nodule abundance determined based on box corer data and the seafloor nodule coverage at the sampling site
In the H22 exploration block, with the highest degree of exploration in the entire area administered by the Interoceanmetal Joint Organization (IOM), the strength of their correlation varied from moderate to a statistically insignificant correlation
Summary
The amount of polymetallic nodule resources and the metals they contain is among the more important factors in considering nodule deposits as attractive from the point of view of their future exploitation. Direct sampling of the ocean floor with the use of box corers (or grab sampling, trawl sampling) is insufficient to obtain an acceptable accuracy of resource estimates, especially in small parts of potential deposits, which is important for the development of a detailed exploitation scenario In this situation, in order to increase the reliability of the estimates, it was natural and rational to pay attention to the possibility of using indirect methods of determining nodule accumulations, such as the results of hydroacoustic surveys and photographic surveys of the seafloor, carried out systematically and continuously along the course of the research vessel. Nodule resources are conservatively estimated to total 21 billion dry tons [30]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
