China's Gaofen 5B Earth-observation satellite has helped identify two point sources of methane emissions in the US state of New Mexico as it passed the region, according to Zhang Yongguang, a professor at Nanjing University.

Based on a satellite image captured by the advanced hyperspectral images Gaofen 5B carried in February, the gradient of methane concentration in the two locations is estimated to be an enhancement of 25 parts per billion to 350 parts per billion higher than the background atmospheric methane concentration, he told China Daily on Wednesday.

With the help of images from other satellites and online company information, he concluded that the emissions are from a shale gas well belonging to EOG Resources and a compressor station of Matador Resources, both of which are energy companies.

Zhang pointed out the shale gas well as a super emission source that has "produced a large amount of methane leakage". The hourly emissions from it are about 7.3 to 16.1 metric tons, he said.

He said roughly 0.4 to 0.8 tons of methane is emitted per hour from the compressor station.

Methane is a much more potent greenhouse gas than carbon dioxide. During the first 20 years that methane is released into the atmosphere, it is 80 times more efficient in trapping heat than carbon dioxide.