Dives set for deep-sea mission

A device designed to gather data, including water temperature, salinity and depth, is readied for use on Monday, ahead of submersible Jiaolong's planned deep dives. Liu Shiping / Xinhua

China's manned submersible, Jiaolong, will conduct a dive in the Mariana Trench on Tuesday.

Its mother ship, Xiangyanghong 09, set sail last week for the Yap and Mariana trenches, with the Jiaolong and 96 scientists aboard.

The ship arrived in the Mariana Trench area on Monday and started testing water temperature, salinity and depth for Tuesday's dive. Ten dives are planned for the expedition. The first is expected to reach a depth of 4,800 meters and last about nine hours.

According to Tang Jialing, chief crew member in Tuesday's operation, the dive will take place near the steep northern slope of the Challenger Deep within the trench. The Challenger Deep is the deepest known point in the Earth's seabed hydrosphere, at about 10,900 meters.

With its two mechanical arms, the submersible will collect samples of seawater, sediment, deep-sea life and rocks.

The mission will study the mineralogy and geochemistry of sediment and rocks in the area to learn more about geological activity there. Research will include deep-sea microbes and other life-forms, Tang said.

After Tuesday's dive, the next four dives in the trench will reach depths of up to 6,700 meters.

According to Wu Changbin, commander of the expedition, Jiaolong will survey the abyssal zone - which at depths of between 4,000 meters and 6,000 meters is in perpetual darkness - to learn more about adaptive mechanisms of marine life in extreme environments.

The 38th Oceanic Scientific Expedition started on Feb 6. The Jiaolong made dives in the northwestern Indian Ocean and the South China Sea in the mission's first two stages.