Illustrated vehicles not to scale. Depths measured from surface. Oil well and borehole values are vertical, not measured depths. Depth of geological layers and seabed, and distance to centre of Earth, varies across geographical locations. Distance to the centre of the Earth here taken as the volumetric mean radius of the Earth: 6,371km. Depths are maxima except where stated. Sea creature depths are lower limit of normal depth range, except where stated. Maximum depths may exceed this.