Mid-Indian Ridge, submarine ridge of the Indian Ocean that is a direct continuance of the Mid-Atlantic Ridge; both are segments of the worldwide midoceanic ridge system. Entering the Indian Ocean from the South Atlantic, the Mid-Indian Ridge extends north to a point near Rodrigues Island, where it divides into two parts: one segment continues northward toward the Gulf of Aden, where it connects with the East African Rift System; the second branch extends southeast toward the Macquarie Islands. Between the Gulf of Aden and Rodrigues Island, the Mid-Indian Ridge bears the name Carlsberg Ridge. The ridge is associated with a belt of earthquake epicentres and, hence, is seismically active. This fact is further observed in its rough relief and thin sediment cover.