Beneath the seafloor in northern Israel's Haifa Bay, a vast system of vents is leaking gassy emissions into the eastern Mediterranean Sea, scientists have discovered. If disturbed, this undersea reserve could disrupt the surrounding marine environment and might even unleash greenhouse gases into the atmosphere.
At the outset of their study, researchers from the University of Haifa found more than 700 pockmarks (some at least 200 feet, or 60 meters, across) in the seabed that they suspected were active gas springs. Further geophysical investigation indicated these indentations were actually connected to a 27-square-mile (72-square-kilometer) reserve on the continental shelf, which is letting some gas escape from relatively shallow depths between 121 and 367 feet (37 and 112 meters) below sea-level.
"We don't know yet what kind of gas we're talking about, but its role in undermining the stability of the seabed is clear," Michael Lazar, a member of the research team, said in a statement. "This means that any discussion of marine infrastructure development must seriously relate to this shallow gas stratum."
Israel has been expanding its energy production efforts, meaning they are also developing more infrastructure to transport natural gas from deep-sea drilling back to the shore. Some of these projects will include pressure-reducing facilities built on the continental shelf. Now that scientists know about the shallow system of gas springs, they can take precautions not to disturb it.
"Now we are beginning to understand that there is no substitute for thoroughly researching the stability of the seafloor to prevent an infrastructure failure, since any leak could cause an ecological disaster," said study researcher Uri Schattner.
Seafloor seeps have the potential to release potent greenhouse gases like methane, but they're also associated with unique undersea ecosystems, supporting gas-eating microbes, mouthless worms other unusual forms of life. Scientists don't fully understand how much methane leaking from the seafloor contributes additional carbon to the atmosphere, but the new findings suggest that gas deposits in continental shelves might be releasing more methane into the sea than previously thought, at least in the Mediterranean and possibly in other mid-latitude areas.
The scientists are planning further expeditions to the springs to better understand of the type of gas seeping from this deposit and its influence on marine life near the seafloor.
Their research was published recently in the journal Continental Shelf Research.