Abyssal plains were not recognized as distinct physiographic features of the sea floor until the late 1940s and, until very recently, none had been studied on a systematic basis. They are poorly preserved in the sedimentary record, because they tend to be consumed by the subduction process. Due to infinite darkness, and a water pressure that can reach up to 76 megapascal, abyssal plains are not very well explored, and some can say that the Moon is better explored in comparison to abyssal plains.