Registering from space intensive gas seeps on the sea surface due to damage to Nord Stream 1 and Nord Stream 2 gas pipelines

Abstract

Anomalously intensive gas seeps on the sea surface due to damage to Nord Stream 1 and Nord Stream 2 underwater gas pipelines in the Baltic Sea have been analyzed using optical (Kanopus-B and Sentinel-2B) and radar (Sentinel-1A) satellite images. Positive contrasts of NRCS (up to 7.5 dB) registered by Sentinel-1A radar and of spectral reflectance (up to 0.73 units) registered by Kanopus-B and Sentinel-2B optical sensors have been detected in the area of such gas seeps. Those seeps’ features were revealed on the sea surface, namely dome-shaped swells, fountains, vortices, foam, wave breaking, surface wave structure disturbance, and wind shadow. Taking into account the volume and density of gas located in the damaged pipelines, it is shown that the total volume of methane release was no more than ~ 0.51 Tg, i. e., less than 0.1% of the annual global methane emissions into the atmosphere.