Jiaolong plumbs deepest region of the ocean

The Jiaolong, China's manned submersible, dived in the Mariana Trench on Tuesday, making the first of a series dives for the third stage of the country's 38th oceanic expedition.

The craft reached a depth of 4.8 kilometers at 9:49 am and remained submerged for about nine hours in all, said Tang Jialing, the pilot of the Jiaolong.

The Mariana Trench - in the western Pacific Ocean about 200 km southwest of Guam - is the site of Challenger Deep, the deepest valley in the ocean. Tuesday's dive was made along the northern slope of the 11-km-deep valley.