Itziar Irakulis-Loitxate , Javier Gorroño , Daniel Zavala-Araiza , Luis Guanter

Mitigation of methane emissions from fossil fuel extraction, processing and transport is one of the most effective ways to slow global warming. Satellite-based methods are being instrumental for the detection, characterization, and quantification of this type of emissions. However, despite the rapid development of satellite-based methane plume detection methods for terrestrial surfaces, there is still an important observational gap with respect to offshore oil and gas infrastructure—which accounts for roughly 30% of global production. This is mostly caused by the low reflectivity of water at the shortwave infrared wavelengths used for methane remote sensing. In this work, we have used observations from the WorldView-3 and Landsat 8 satellite missions in a particular observation-illumination geometry to image offshore methane plumes from space. The study site is an offshore oil and gas production platform in the Gulf of Mexico, near the coast of Campeche, in one of Mexico's major oil producing fields. Our data suggest that the platform vented high volumes of methane during a 17-day ultra-emission event, amounting to 0.04 ± 0.01 Tg of methane released to the atmosphere if integrated over time. Our results illustrate how satellites can detect methane plumes from offshore infrastructure, which represents a significant breakthrough in the monitoring of industrial methane emissions from space.