Rapid emplacement of a mid-ocean ridge lava flow on the East Pacific Rise at 9° 46′–51′N

Abstract

In April, 1991, during a submersible diving expedition to the East Pacific Rise (EPR) crest at 9°46′–51′N, a new volcanic eruption on the sea floor was discovered. Here, we report results from numerical modeling of that eruption, which indicate that ∼ 4 × 106 −6 × 106 m3 of lava was emplaced in ∼ 1–2 h, with an average eruption rate of ∼ 103–106 m3 s−1 — comparable to rates observed in Hawaii at Kilauea's East Rift Zone. If the rapid emplacement of the 1991 EPR lava and its short eruption duration are typical of volcanic events at fast-spreading mid-ocean ridge crests, these characteristics have broad implications for our ability to detect, monitor and understand the evolution of magmatic and volcanic processes within the axial zone.