IMAGINE a structure thousands of metres under the ocean surface that is home to autonomous robots. One by one, the vehicles leave, mapping terrain and looking for unusual creatures.
We know very little about life at these depths, but such robots could uncover a bit more with every trip. As their power runs low, they return to tell HQ what they have discovered and recharge their batteries.
This is the vision for China’s ambitious plan to build the world’s first deep-sea base. Details are scarce, but there are clues to what it may be like in prototypes, documents from the Chinese Academy of Sciences, which is leading the project and which aims to have results within five years, and comments from China’s president Xi Jinping.
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The base itself will probably include a chamber to trap passing organisms, such as the weird eels, sharks or sea cucumbers that inhabit the deep ocean. If brought to the surface, these creatures often die. So being able to study them in the base will help our understanding of how they survive at these depths.
Below about 200 metres, hardly any sunlight penetrates, so solar panels are useless. A base will need a power cord that can reach a surface ship or the shore.
China has built several prototypes of robot submarine docking stations in recent years. Each looks like a giant megaphone and a torpedo-shaped submarine docks in the cone part to recharge and transmit data. Currently, the docking system has only been tested to a depth of 105 metres.
The ocean floor is still largely unexplored. Less than 1 per cent is currently mapped in detail. So robot submarines will include sonar to reveal what is where with much greater resolution.
One advantage of a permanent base is it allows you to see how things change over time, rather than just getting a snapshot by sending down a submarine for a single visit, says Jon Copley at the University of Southampton, UK.
Such a facility could result in better data on underwater landslides and volcanic eruptions that can trigger earthquakes and tsunamis. Knowing more about these events would be valuable for improving modelling, which could ultimately save lives on land. “The ocean covers most of our planet, and what happens there affects us all,” says Copley.
“Intense ocean exploration may shed light on one of Earth’s big mysteries: the origin of life”
What is more, the intense ocean floor exploration made possible by a base and autonomous submarines may shed new light on one of Earth’s big mysteries: the origin of life. Sampling robots could hunt for microorganisms, or their fossils, that have existed since the early Earth, says Douglas Bartlett at the University of California, San Diego. “They may be the missing link between primitive life and eukaryotes, which include us,” he says.
The station may also be the first step to building an underwater factory to support deep-sea oil extraction or the mining of precious minerals, says Weicheng Cui at the Hadal Science and Technology Research Center in Shanghai. “We are already extracting resources from the deep ocean,” says Cui. So, it may be cost-effective in the long run to have a facility for preliminary processing before bringing them back up, he says. However, both oil extraction and mining risk destroying ocean ecosystems.
China’s deep-sea ambitions won’t be easy to fulfil. Salinity, the cold and high pressure make the ocean depths a tough place to operate, says Justin Manley at Just Innovation, an undersea technology consulting firm.
As a result, everything will need multiple back-up systems. For example, robotic submarines may have more thrusters than they need so that if one breaks, others can still do the job, says Manley.
Copley is open-minded about possible locations for the base. “Frankly anywhere in deep water could be interesting for science,” he says. But because the base needs to be connected to a surface power source, it can’t be too far from the shore.
China hasn’t yet released a proposed location, but the involvement of Hainan, the country’s southernmost province, suggests the 5400-metre-deep Manila trench on the edge of the South China Sea could be a possible site. Another could be the 1100-kilometre-long Okinawa trough that extends from northern Taiwan to southern Japan in the East China Sea.
Both areas are near the boundaries of continental plates, where underwater earthquakes and landslides frequently occur. However, the locations could be contentious, as they are in disputed waters.
