Red Sea Floor Is Leaking Vast Amounts of Gas, Scientists Discover

One would expect the massive Middle Eastern petroleum industry to affect air quality over the whole region, including the Red Sea – and it does. But scientists on a 2017 shipping expedition in the Arabian Peninsula were astonished to discovery that ethane and propane levels in the northernmost Red Sea were up to 40 times higher than predicted.

Around the world, atmospheric concentrations of ethane and propane correlate with industrial activity, and the oil industry and pollution from gas flares can explain high concentrations over the Arabian Gulf and Suez Canal. But anthropogenic elements couldn't explain the high levels of propane and ethane over the northern Red Sea. Some agency other than industry was at play, and on Tuesday the explanation was published in Nature Communications.   

To their surprise, deep analysis found the answers at the bottom of the Red Sea. Israel isn't affected because it is upwind from the emissions point, lead author Dr. Efstratios Bourtsoukidis of the Mainz-based Max Planck Institute for Chemistry (which also organized the expedition) tells Haaretz. The affected areas are mainly southern Egypt's Red Sea coast, Sudan, and Saudi Arabia.

The amount of gases rising from the seabed is comparable to the total anthropogenic emissions from entire individual Middle Eastern countries such as Iraq, the United Arab Emirates and Kuwait, the team reports.

But whence is this gargantuan emission of gaseous hydrocarbons from the seabed? The Red Sea lies between the Arabian and African continental plates, Bourtsoukidis explains. The southern Red Sea floor has been spreading for the past 5 million years, while the northern part is in a stage of continental rifting. Tectonic and seismic movements fracture the seafloor, which can potentially cause emission bursts.

More emissions come directly from dense super-saline water on the seafloor rising surface-ward, bringing gases seeping from hydrocarbon reservoirs – and from leaking wells.

In short, much of the "surplus" gas is natural in source, but there is an anthropogenous contribution. The magnitude of each contribution remains to be determined, Bourtsoukidis qualifies. But it seems that their cumulative contribution represents the missing source of the huge gas concentrations above the northern Red Sea, the team says.