A note on the morphology and tectonics of Kainan Maru Seamount, East Antarctica

Abstract

Kainan Maru Seamount lies off the northern end of the Gunnerus Ridge along the margin of East Antarctica. The seamount is separated from the Gunnerus Ridge by only about 15 km. Detailed Hydrosweep multibeam surveys of the seamount have shown that the seamount rises over 3,500 m above the surrounding seafloor, has an oval shape about 60 km wide and 120 km long, and has a gently sloping summit. The northern and eastern sides of the seamount are steeper than the southern and western sides. Many erosional channels cut the northern and eastern flanks of the seamount, whereas the western side shows evidence of large sediment slides and is more gently sloping. The morphology of the seamount, as observed in the bathymetry and satellite gravity data, suggests that Kainan Maru Seamount may be a detached piece of the Gunnerus Ridge that rotated clockwise away from the ridge during the rifting of Gondwanaland in this area