The southern edge of the plate is bordered by the Antarctic Plate, forming the South Scotia Ridge, a left-lateral transform boundary sliding at a rate of roughly 7.4–9.5 mm/yr that occupies the southern half of the Antarctic-Scotia plate boundary. The relative motion between the Scotia Plate and the Antarctic Plate on the western boundary is 7.5–8.7 mm/yr. Though the South Scotia Ridge is overall a transform fault, small sections of the ridge are spreading to make up for the somewhat jagged shape of the boundary.