SEABED AUTHORITY WORKSHOP MAPS PROJECT TO MODEL POLYMETALLIC NODULE DEPOSITS IN NORTH PACIFIC

SEABED AUTHORITY WORKSHOP MAPS PROJECT TO MODEL POLYMETALLIC

NODULE DEPOSITS IN NORTH PACIFIC

(Received from a UN Information Officer)

      NADI, FIJI, 20 May -- A blueprint for clearer scientific assessment of polymetallic nodule deposits on the deep seabed of the Equatorial North Pacific Ocean has been prepared by a workshop of the International Seabed Authority (ISA), held at Nadi, Fiji, from 13 to 20 May.

This project is designed to produce over four years a geological model for nodules in the Clarion-Clipperton Zone (CCZ), a 2,500-mile swath of the Pacific southeast of Hawaii that contains the richest supply of these rocks anywhere in the earth’s oceans.  The model is designed to identify the many factors –- chemical, physical and biological –- that contribute to the creation and growth of nodules.  It should assist scientists to understand the underlying processes and help prospectors find the most valuable deposits.

The Workshop recommended a work programme leading to a reliable geological model within three or four years.  It would be divided into three phases, starting with data acquisition and processing, moving on to analysis, and culminating in the production of a geological model with the stated aim of improving resource assessment.  A “prospector’s guide” is to accompany the model, giving descriptive explanations of nodule geology to complement the quantitative approach of the model.  The project would rely mainly on data already available, rather than original research.

The model is to cover the broad range of factors that affect the two measures of greatest interest to both prospectors and scientists:  abundance of nodules and their metal content.  The metals of commercial interest found in polymetallic nodules are cobalt, copper, manganese and nickel.

The Workshop produced a number of specific recommendations on what the model should cover and how the work should proceed.  One intermediate product would be an evolutionary framework for the Pacific plate underlying the CCZ, covering the past 20 million years –- the life span of the oldest nodules.  Evidence would also be examined on features such as hydrothermal activity (hot springs) on the ocean floor; the Workshop was told of a recent discovery that signs of such activity had been found at the centre of the CCZ. 

The Workshop envisaged the prospective model as offering the best possible resource assessment for polymetallic nodules in the CCZ, along with a summary of factors that would help in evaluating existing mining claims and in selecting areas for new claims.  In general, it would provide an authoritative description of an important oceanic regime, integrating geological processes with those on the seabed and the waters above.

The model will not attempt to gauge what abundance and metal grades would be sufficient to support seabed mining, given the unpredictability of future mining costs and land-based mineral prices that has so far inhibited commercial activity.

The model is to be used by the Authority to assess the metals of commercial interest in the reserved areas and to serve as a predictive model for poorly surveyed sectors of the CCZ.  It is also expected to serve a broader audience, including contractors active in their assigned areas and independent scientific institutions working on nodule resource development issues.  Moreover, Workshop participants have suggested that, while primarily applicable to the CCZ, the model could help clarify issues surrounding nodule formation elsewhere in the Pacific and in other oceans, in both international waters and those under the national jurisdiction of coastal States.

Land-based miners have long used models to identify the most favourable locales for prospecting.  Such models attempt to predict where the richest ore deposits or petroleum fields occur on the basis of the surrounding topography and sub-surface formations.  A model for nodules should prove even more challenging, as it must also take account of many biological determinants of nodule growth that do not figure in land-based assessments.  Moreover, the CCZ model will cover a much larger area –- about 4.5 million square kilometres -– than the local models usually prepared for land-based mineral prospectors.

A fuller account of the Workshop proceedings, including summaries of the scientific presentations, may be found on the ISA Web site:  www.isa.org.jm.

* *** *