In Boston and many other aging cities in the Northeast, a maze of underground low-pressure natural gas pipelines are riddled with leaks. The research team, led by Nathan Phillips, an associate professor of earth and environment at Boston University, measured atmospheric methane concentrations along all 785 miles of road within Boston’s city limits with a highly sensitive device known as a cavity-ring-down mobile CH4 analyzer.

They discovered 3,356 leaks of methane whose isotopic characteristics indicated that they originated in fossil fuel rather than microbial sources. Some leaks clocked in at more than 15 times the global background methane level, the researchers write in the journal Environmental Pollution.

“There are two ways to get a sense of the leak rate of methane,” Dr. Phillips said. “You can go out to the leaks on the ground and put chambers over them and measure how much is coming out, but that is incredibly tedious with over three thousand leaks in the city. Or, you can use the integrating power of the atmosphere itself.”

With the data, the team has created the first comprehensive and publicly available map of leaks in any city.

SOURCE: http://green.blogs.nytimes.com/2012/11/20/methane-is-popping-up-all...