首页   按字顺浏览 期刊浏览 卷期浏览 Quantitative estimation of seafloor features from photographs and their application to ...
Quantitative estimation of seafloor features from photographs and their application to nodule mining

 

作者: Rahul Sharma,  

 

期刊: Marine Georesources & Geotechnology  (Taylor Available online 1993)
卷期: Volume 11, issue 4  

页码: 311-331

 

ISSN:1064-119X

 

年代: 1993

 

DOI:10.1080/10641199309379926

 

出版商: Taylor & Francis Group

 

关键词: seabed photographs;nodule estimation;application to mining

 

数据来源: Taylor

 

摘要:

Methods developed for quantitative estimation of seafloor features from seabed photographs and their application for estimation of nodule sizes, coverage, abundance, burial, sediment thickness, extent of rock exposure, density of benthic organisms, and their lebensspuren have been presented. Digitization of the photographs shows variable nodule size (< 1 to 10 cm), coverage (< 1 to 75%) and abundance (< 1 to 20 kg/m2). Nodule population is inversely proportional to the coverage of the sediment (10–100%) and its thickness (0 to > 10 cm), which causes differential burial (0–100%) of nodules. Correlation between nodule parameters (diameter and coverage) in the photographs and grab recovery is used to evolve empirical relationships for estimating nodule abundance in different seabed settings. The rock outcrops (basalts) with a coverage of 6–100% are the sources of nuclei for the nodules, the distribution of which is controlled by the local topography. Higher concentrations of nodules are observed along the slopes, followed by the crests of seamounts, and are lowest in the valleys and plains. A population density of 6–7 benthic organisms per 100 m2belonging to 7 different phyla is observed, with a high frequency of lebensspuren (4–12 traces/m2) in association with nodules. Estimation of these parameters can be used as important inputs in the design of the nodule collector, as it will have to encounter a variety of seafloor conditions, such as patchy nodule distribution, rock outcrops, steep slopes, and frequent microtopographic changes, as well as benthic life. The distribution and relation of various features with one another can also be used to understand the possible impact of nodule mining on the seabed. Estimates show that for a yield of 3 million tonnes of nodules per year, the volume of sediment disturbed will be between 200 × 107and 500 × 107m3over an area of 300–600 km2, depending upon the average abundance of nodules. Hence, the nodule collector will have to be a self‐propelled system, with photographic and acoustic sensors, to enable selective mining and avoid unfavorable areas.

 

点击下载:  PDF (1399KB)



返 回