Scientists say buried volcanic rocks off the coast of Long Island, as well as other parts of the east coast, might be ideal dumping grounds to lock away global-warming carbon dioxide emissions.
Underground burial of carbon dioxide is the subject of increasing study across the country. But up until now, research in New York has focused on inland sites.
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A study this week in the Proceedings of the National Academy of Sciences outlines formations on land as well as offshore, where scientists from Columbia University’s Lamont-Doherty Earth Observatory say the best potential sites may lie—areas of more than 1,000 square kilometers each, off Long Island, northern New Jersey and Massachusetts.
“We would need to drill them to see where we’re at,” said geophysicist David Goldberg, who led the study. “But we could potentially do deep burial here. The coast makes sense. That’s where people are. That’s where power plants are needed.”
Goldberg said the undersea formations of basalt, an extremely porous volcanic rock, could be the most useful, for several reasons.
They are deeper—an important factor, since CO2 pressurized into a liquid would have to be placed at least 2,500 feet below the surface for natural pressure to keep it from reverting to a gas and potentially then making its way back to the surface. And while land sites are relatively shallow, those at sea are covered not only by water, but hundreds or thousands of feet of sediment, and appear to extend far below the seabed.
In addition to providing pressure, sediments on top would form impermeable caps, said Goldberg. The rocks are thought to contain porous layers with plenty of room for CO2 to fit, simply by displacing seawater. On land, by contrast, there are concerns that drilling and injection could disturb aquifers or otherwise get in the way of neighbors.
“The basalt itself is very reactive, and in the end, you make limestone,” said coauthor of the study Dennis Kent, of Rutgers University. “It’s the ultimate repository.”
The scientists estimate some sites could store close to a billion tons of CO2—the equivalent of the emissions from four 1-billion-watt coal-fired plants over 40 years.
