Exploring the Deep Sea

By TANG YUANKAI

JAMES Cameron is great, says Wang Pinxian, a professor at Tongji Universitys School of Ocean and Earth Science and an academician of the Chinese Academy of Sciences.

Wangs not talking about films like Avatar and Titanic, directed by Cameron. Rather, hes interested in the Canada natives record-breaking dive to the bottom of Challenger Deep, the deepest part of the Mariana Trench, and of all earths oceans. When Cameron descended 10,898 meters below sea level on March 26, 2012, he became the first person to complete the dive solo.

Wang Pinxian may not be a film director, but hes certainly at the forefront of Chinese oceanography. His chief project is perfecting a Chinese design for a oneman submersible capable of reaching great depths. Called Jiaolong – a dragon in Chinese mythology – Wangs craft is used for marine scientific research.

From a practical point of view, Wang is keen to point out the links between exploration of the sea, the rich resource deposits that lie beneath the sea floor and the future of Chinas economic and societal development. Marine research reveals our planets history, and gives clues to its future, he says. “Dive down several thousand meters and the seas secrets reveal themselves. Besides, we also get to learn a lot more about the workings of the planet we call home.”

The highest mountain in the world is Mount Chomolangma, at 8,844.48 meters. The Mariana Trench, however, bottoms out at a breathtaking 11,034 meters. If Mount Chomolangma were to rise from that depth, you would need to place 7 Eiffel Towers on top of each from the mountains peak just to reach the waters surface.

“The sea is so mysterious and unfathomable!” says Wang, excitedly. Hes now 76 years old and has been working in the field of oceanography for decades.

Last year, Wang was awarded a RMB 150 million grant by Chinas National Natural Science Foundation to lead an eight-year study into the geology and biology of the South China Sea, the largestever such project.

“The South China Sea is a Mecca for oceanographers and climatologists,”Wang says, adding its been his dream to do research in the sea for many years.

Further down the line, Wang hopes the Ocean Drilling Program (ODP) will come for a second time to the South China Sea in 2014. Wang wants to see China take a lead in ODP research and for Chinas own drilling designs to be employed.

The U.S. initiated the ODP, which was co-sponsored by more than 10 countries, in 1985. China joined in 1998. Early on, Wang and several other Chinese scientists submitted a proposal to the program on East Asian monsoons in the South China Sea and their influence on global climate. This proposal was well received in the international scientific community and gave birth to ODP Leg 184 in the South China Sea in the spring of 1999. Wang was one of two lead scientists on the project, which marked the first time China had done drilling research in the sea. It was a landmark event, both for China and for marine science in general. The South China Sea, extending far south from Chinas mainland, is technically a marginal sea of the West Pacific. Sediment accumulated in the sea due to the erosion of surrounding mountains makes it possible to construct detailed records of the regional climate over the past 45 million years.

In the sea, the monsoon drives the currents that go on to influence the Indian and Pacific oceans. Climatically speaking, it is an incredibly important area.

“Since China has sovereignty over the Xisha, Zhongsha and Nansha islands in the South China Sea, its really our duty to explore it. Doing marine science there will help us understand our own country better,” Wang says.

When Wang led the drilling of 17 holes in 1999, his team acquired continuous core samples of 5,500 meters. In the following years of analysis and research, they constructed a palaeoenvironment and stratum profile of the past 32 million years in the west Pacific Ocean. This has significantly contributed to helping the world scientific community understand changes in the macro-environment.

In studies based on the 1999 data, Wangs team also set out to explore the monsoon. Here, Wangs wife Sun Xiangjun, a researcher at the Institute of Botany of the Chinese Academy of Sciences and adjunct professor at Tongji University, has special expertise. She ended up discovering the culprit for the East Asian monsoon: a terrain inversion that took place roughly 25 million years ago. This theory has now replaced the former explanation that the monsoon was due to changes in volumes of highlatitude ice in the North Atlantic Ocean.

In fact, both the West Pacific and the North Atlantic have a role to play, says Wang. “If the North Atlantic is the start button, then the West Pacific is the engine. Both are important causes of climate changes in the macro-environment.”

Wang has made major contributions to his field. But his success didnt come easily.

Wang received his first degree in geology from Moscow State University in 1960. Before Chinas 1980s reforms, he had to make do with outdated equipment in his marine research. His laboratory was a converted workshop in an abandoned factory. Subsidies were out of the question. His most valuable resource was an encyclopedia on paleontology in Russian. And yet, despite the meager conditions, Wang set about evaluating offshore microfossil samples.

Times have changed and equipment has improved, but Wang is still as committed as ever to his research agenda. To recognize Wang for his near-five decades of climate research, the European Geosciences Union in 2007 awarded him the Milankovich Medal, their top honor in paleoclimate and oceanographic research.

Back in the South China Sea, there is also a monetary value to Wangs drill- ing discoveries – he has found natural gas and gas hydrates. “There are natural deposits of frozen ice containing methane, known as gas hydrates, lying on the ocean floor. If we light them, the ice melts away and methane is released. Its a good fuel – clean and natural.”

Scientists estimate world reserves of this “ice petroleum” to be much higher than remaining petroleum resources.“If we can exploit it cheaply and safely, humanity need not worry about its fuel requirements for many years to come,”Wang says.

expecting the Unexpected

With further studies by Wang Pinxian and other scientists at home and abroad, the hypothesis that everything relies on the sun for growth may have been turned on its head. The suns rays penetrate only 200 meters below the oceans surface. It was once believed there were no living creatures 600 meters below the surface. We now know this to be false, and living creatures have even been documented in the Mariana Trench itself.

“The most wonderful part of nature is its unpredictability,” says Wang. Thousands of creatures survive in the oceans depths – how the food chain functions in an environment of eternal darkness is still beyond our understanding. Its a whole new frontier.

Explaining this frontier, Wang says:“Organisms at those depths rely on terrestrial heat instead of the sun. Sulfur bacteria from the earth are transformed into organic matter through chemical reactions. The organisms spawned of these reactions can grow to huge sizes.”He gives an example: an earthwormlike creature can grow to three meters in length, and has neither a mouth nor an anus. There are also shells and microorganisms down there whose essential biology hasnt changed for several million years.

“The seas are seemingly bottomless. Below the seas we also find ‘groundwater, known as ‘sea below the sea.”

At the deepest depths of traditional seas we see currents that flow in different directions, as well as hydrothermal vents and cold seawater. Hydrothermal vents produce features called “black smokers”– chimney-like structures around which life flourishes into complex communities of organisms that feed on the heat and chemicals of vents outflow.

There is significant interaction between the deepest parts of oceans and the surface. Water and carbon matter cycle between the surface and the ocean floor.In an environment in which the seabed is eternally shifting due to tectonic plate movement, no conditions are unchanging in the oceans.

In Wangs eyes, exploring the world under the sea offers humans the opportunity to see the Earth from a new perspective, and to research and build new areas of knowledge.

People-carrying bathyscaphes, like the one used by James Cameron in his recent descent, in addition to drilling ships and observation networks, are the three key tools for exploring the deep sea. “In China, we now have the first two, but we still need an observation network,” Wang says.

Though in his mid-70s, Wang is still as passionate as ever about his research and its potential. “Drilling ships heading out to sea from time to time can make solid contributions, but underwater observation networks – permanent research posts – offer really exciting possibilities. Like a laboratory or weather station, the observations of the underwater network will be sent back to us via optical cables. This will afford us new insights into the last great unexplored territory on earth– the deep sea.”