Exposed combustible ice found

Chinese scientists use Raman probe in S.China Sea seabed

Chinese scientists have, for the first time, discovered exposed combustible ice on the seabed of the South China Sea, and the discovery was published in the international academic journal Geochemistry, Geophysics, Geosystems on Friday.

The Chinese expedition team using a Raman spectroscopy probe detected the combustible ice – a type of natural gas hydrate – at a depth of 1,100 meters off the South China Sea, the China Central Television (CCTV) reported Friday.

Data collected from the Raman probe designed by Chinese scientists showed that the exposed combustible ice contains large amounts of methane and hydrogen sulfide. It could serve as an energy source for deep sea life, the CCTV report said.

Combustible ice is usually found in seabed or tundra areas which have the high pressure and low temperatures needed for the ice to form and continue to exist. It can be ignited like solid ethanol, the Xinhua News Agency reported.

One cubic meter of combustible ice is equal to 164 cubic meters of regular natural gas, Xinhua said.

Combustible ice exposed on the surface of the seabed needs large quantities of deep-marine cold seep fluids as air supply, thus making it difficult to preserve. The detection provided a natural experimental field to study its formation, decomposition and interaction with the marine environment, the CCTV report said.

“The extraction of exposed combustible ice is less difficult and costs less than if found in seabed or tundra areas,” Yang Fuqiang, senior advisor on climate and energy at the US-based Natural Resources Defense Council, told the Global Times on Friday.

“But unlike the usual combustible ice which has crust to protect the methane it contains, extraction of such poses a high risk of methane leakage,” Yang warned.

China first announced it had successfully collected samples of combustible ice in the South China Sea on May 18 after discovering the substance in the region in 2007.

After extracting during a 60-day period, China broke a world record for the total amount extracted at more than 300,000 cubic meters and the length of time it took, the People’s Daily reported in July.

Yang said that methane, once leaked, could become a hazard in the South China Sea and exacerbate global warming.

Chinese scientists have to develop new technology to extract the exposed combustible ice, he noted.

Chinese scientists have made significant achievements in both technological and engineering terms in extracting combustible ice in 2017, including reliable sand contamination prevention, environmental protection, safe and sustainable production, and adjusting gas production capacity, domestic news site chinanews.com reported.