Recent developments in deep ocean hydrothermal exploration

Since the first discovery of hydrothermal activity in the late 1970´s no more than ~20% of the world´s deep ocean mid-ocean ridge system has been investigated systematically for high-temperature hydrothermal circulation. Yet the exploration that has been conducted, under the auspices of the InterRidge program and, more recently, the Census of Marine Life has revealed that hydrothermal activity exists along ridges of all spreading rates and in every deep ocean basin. Furthermore, a plausible hypothesis has emerged that the world´s largest and longest-lived seafloor hydrothermal systems may be generated on that 50% of the global ridge-crest (25-30,000km in extent) that is classified as slow or ultra-slow spreading, extending the length of the Atlantic Ocean from the high Arctic and the Norwegian-Greenland Sea through to the SW Indian Ocean as far as the Rodriguez Triple Junction. This section of the global ridge crest remains predominantly unexplored yet is already known to host multiple discrete biogeographic provinces. Clearly, increased efficiencies of exploration are required, migrating from conventional, systematic surveys of the water column by tow-yo´d CTD-rosette packages and suitably instrumented deep-tow vehicles (the 1990´s state of the art) via pioneering AUV approaches demonstrated in the first decade of the 21st Century to the long-range, artificially intelligent vehicles of the future.