Southern EPR at 17.5°S (Segment K) Volcano — Undersea Features

Lava flows from a very recent eruption were observed in 1994 along segment K of the southern East Pacific Rise. This segment of the mid-ocean ridge north of the Easter microplate displays the broadest cross-sectional area and the shallowest depth (2,566 m) of the southern East Pacific Rise between 13°40' and 18°30'S. Glassy, unsedimented lava flows on the 17.5°S segment of the East Pacific Rise were considered, from biological observations and chemical analyses of the plume and vent fluids, to have been erupted within 2-3 years of a November-December 1993 plume survey. Lava was erupted along two segments, a 4-km-long flow at the southern site and a 5-10 km flow at the northern site. Numerous low- and high-temperature hydrothermal vents are active along this segment of the ridge.