On the role of geologic factors in determining peculiarities of water mass structure in the Clarion-Clipperton ore field

Comprehensive geological, hydrophysical, and hydrochemical studies, carried out on reference transects in pioneer areas of IOM and COMRA have shown that the peculiarities of water mass structure and dynamics of its variability are substantially affected by geological factors such as deep-sea volcanism, hydrothermal activity, and seismicity. Those factors bring about episodic events of environmental pollution, comparable in scale with a potential anthropogenic pollution resulting from polymetallic nodule mining. This problem calls For a long-term monitoring of reference transects in pioneer areas. as a basis for investigating spatio-temporal variability of the marine environment so that it can be protected from unacceptable changes brought about by the contractors' activities.