Storing Carbon in Deep Ocean Rocks Could Reduce Climate Threats

Scientists from the University of Southampton claim to have found a possible solution to the ever-increasing threat of carbon dioxide in the atmosphere: store it in particular locations far beneath the ocean. 

Southampton researchers have identified five potential off-shore regions near Australia, Japan, Siberia, South Africa and Bermuda that they say have the geological features suitable for safely storing large volumes of carbon for centuries.

While the movement to use more sustainable and efficient technology has not lost steam, the world still runs on fossil fuels such as coal, oil and natural gas, the burning of which releases huge amounts of carbon dioxide into the atmosphere. Carbon in the atmosphere has been linked to a variety of worrying issues such as climate change and the acidification of oceans.

The researchers contend that while new technologies are being developed to trap carbon at major sources such as power plants, trapping the carbon is only beneficial if it can be kept out of the atmosphere.

Beneath the ocean's surface, igneous basalt rock in the upper ocean crust stretch across a vast expanse of seafloor. Depending on their locations, these regions can cover an area of up to 4 million square kilometers, which the researchers contend is enough room to store extant carbon and other future carbon emissions.

"We have found regions that have the potential to store decades to hundreds of years of industrial carbon dioxide emissions although the largest regions are far off shore," said research Chiara Marieni, a PhD student at Southampton's National Oceanography Centre. "However, further work is needed in these regions to accurately measure local sediment conditions and sample the basalt beneath before this potential can be confirmed."

Injecting carbon into the seafloor is not a new idea in the fight to reign in the world's carbon output. But Marieni's research offers new potential locations on where the carbon could be stored.

A 2006 study by researchers at Harvard University and Columbia University suggested that by storing liquid carbon beneath the ocean, the cold temperature of the water and the pressures of deep sea would be an effective system of keeping the carbon contained.

At the time, the MIT Technology Review reported on the study:

"Once beneath the sea floor, the carbon dioxide would interact with the surrounding fluids and produce hydrate ice crystals, which would plug the rock pores, serving as a secondary cap on the carbon dioxide. Over hundreds of years, the carbon dioxide would dissolve in the surrounding water, and then would only have the potential of leaking out by diffusion, a slow process that would take millions of years."

Whether doing so is technically feasible, especially at great depths far off shore where these potential storage spots are located, remains to be seen.

Marieni and her colleagues' research is published in Geophysical Research Letters.