With a surface size of 26,300 square miles, the Aral Sea was formerly the world's fourth biggest lake. However, the lake has been rapidly diminishing since the 1960s. The lake is diminishing due to the divergence of the main rivers away from the lake for irrigation projects. As of 1997, roughly 10% of the lake had vanished, leaving only patches of smaller lakes. The majority of the south-eastern lake had already dried up by 2009, while the majority of the southwestern lake had dwindled to become a narrow strip along the old southern sea. NASA images from 2014 showed the eastern section of the old Aral Sea, which had completely dried out and is now known as the Aralkum Desert.