Based on the analysis of satellite altimetry and deep-water geological and geophysical surveys, it was established that there is a close connection between underwater volcanoes and tectonics on the crest of the East Pacific Rise, on its western flank and in the deep-water basin. Underwater volcanoes are characterized by different sizes; their basalts are characterized by variable degree of differentiation. The aggregated results denote the existence and relevance of studying the major problem of the volcanic-tectonic activity of the oceanic lithosphere at different stages of its evolution.