The leak emanated from a gas main operated by Wales and West Utilities and has raised alarms due to its potential environmental impact.
Methane has 28 times higher heating potential than carbon dioxide (CO2) and is responsible for about 30% of the global temperature rise.
This particular leak was identified in Cheltenham in March, thanks to the efforts of Emily Dowd, a PhD researcher at Leeds University’s School of Earth and Environment and the National Centre for Earth Observation.
Initially focused on assessing methane leaks from landfill sites using satellite imagery, Ms Dowd stumbled upon the signs of a methane leak miles away from her intended target, originating from a gas pipeline belonging to Wales and West Utilities.
Ms Dowd’s discovery prompted collaborative efforts with methane emissions monitoring company GHGSat, the provider of the original satellite images, to conduct additional space surveys.
Simultaneously, a team from Royal Holloway University conducted ground-level measurements.
Ms Dowd said: “Finding this leak raises questions about the prevalence of such leaks and the need for a more thorough exploration to leverage the technology at our disposal.”
Wales and West Utilities became aware of the leak when a member of the public reported a gas smell.
They were already in the process of getting permission to replace the gas mains when the satellite technology spotted the leak.
The exact cause of the leak is still unknown.