A newly discovered submarine mud volcano in the southeastern continental shelf of Korea: Its evolution through mud volcanism, cold-water coral growth and bottom-current erosion

This study reports the first discovery of a mud volcano off southeastern Korea, based on multi-beam bathymetry, chirp seismic profiles, and sediment core analysis. The dimensions of the mound are comparable to mud volcanoes and mud cones previously identified on the Mediterranean Ridge and Gulf of Cádiz. A deep-rooted diapiric structure and lobate flow-like seafloor at the flanks also support that the mound formed by mud volcanism and mudflows. The mound crest is covered by dead cold-water corals, appearing as cone-shaped mound or rugged seafloor. The radiocarbon ages of coral fragments suggest that the mud volcano formed earlier than 7.1 ka; however, the timing and duration of coral habitation on the mound remain unknown. Currently, the morphology of the mound has been influenced by a strong bottom current, leading to the formation of a moat and drift system around the mound. The discovered mound is thus interpreted as a composite mud volcano that originated from mud volcanism and evolved via cold-water coral colonization and bottom-current erosion.