More than 500 bubbling methane vents have been found on the sea floor off the US east coast, researchers say.
The unexpected discovery indicates there are large volumes of the gas contained in a type of sludgy ice called methane hydrate.
There are concerns that these new seeps could be making a hitherto unnoticed contribution to global warming.
The scientists say there could be about 30,000 of these hidden methane vents worldwide.
Previous surveys along the Atlantic seaboard have shown only three seep areas beyond the edge of the US continental shelf.
The team behind the new findings studied what is termed the continental margin, the region of the ocean floor that stands between the coast and the deep ocean.
In an area between North Carolina and Massachusetts, they have now found at least 570 seeps at varying depths between 50m and 1,700m.
Their findings came as a bit of a surprise.
“It is the first time we have seen this level of seepage outside the Arctic that is not associated with features like oil or gas reservoirs or active tectonic margins,” said Prof. Adam Skarke from Mississippi State University, who led the study.
More than 500 bubbling methane vents have been found on the sea floor off the US east coast
The scientists have observed streams of bubbles but they have not yet sampled the gas within them.
However, they believe there is an abundance of circumstantial evidence pointing to methane.
Most of the seeping vents were located around 500m down, which is just the right temperature and pressure to create a sludgy confection of ice and gas called methane hydrate, or clathrate.
The scientists say that the warming of ocean temperatures might be causing these hydrates to send bubbles of gas drifting through the water column.
They do not appear to be reaching the surface.
“The methane is dissolving into the ocean at depths of hundreds of meters and being oxidized to CO2,” said Prof. Adam Skarke.
“But it is important to say we simply don’t have any evidence in this paper to suggest that any carbon coming from these seeps is entering the atmosphere.”
This research, though, does highlight the scale of methane that is under the waters.
Estimates suggest that these undersea sediments are one of the largest reservoirs on Earth, and contains around 10 times more carbon than the atmosphere.
Prof. Adam Skarke and his colleagues estimate that worldwide, there may be around 30,000 of the type of seeps they have discovered.
They acknowledge that this is a rough calculation but they believe that it could be significant.
While the vents may not be posing an immediate global warming threat, the sheer number means that our calculations on the potential sources of greenhouse gases may need revising.
The scientists also found abundant life around many of these seeps, but not perhaps as we know it.
The creatures they describe are termed chemosynthetic, meaning they derive energy from chemical reactions and not from the Sun as do photosynthetic organisms.
Others who have collaborated on the search for seeps say these discoveries are important.
“These are significant geochemically, as they and our research teams found perhaps one of the largest seeps yet discovered with very active methane bubbling and large amounts of frozen hydrates,” said Prof. Steve Ross, from the University of North Carolina, Wilmington.
“These seeps are also significant biologically, as we have found unique chemosynthetic communities, huge range extensions and increased biodiversity.”
As to the energy potential of these new seeping sources, Prof. Adam Skarke is fairly pessimistic.
The research has been published in the journal Nature Geoscience.
National Grid reported this morning that 393,800 customers are currently without power in Massachusetts due to the snowstorm. Out of them, 4,000 are in Westborough town.
The early winter weather caused wet snow to fall on trees still heavy with leaves – causing falling branches and downed power lines. National Grid emergency, restoration and tree trimming crews are in the field working to restore power.
Debbie Drew, spokesperson for National Grid said:
“We’re going through the process to assess what we have in damage.” She said the process involves starting with repairing the main transmission system.
“The bulk supply is always first.”
“After that is repaired, individual customer power can be restored,” Debbie Drew said.
“Our main concern is safety. The snow, as you know, is like wet concrete.”
National Grid reported this morning that 393,800 customers are currently without power in Massachusetts due to the snowstorm
National Grid spokesperson warned that the snapping trees and downed wires can be dangerous. People should stay away from any downed wire as it could be live.
Debbie Drew said downed wires should be reported by calling 800-465-1212.
Officer Chip Dapolite of the Westborough Police Department echoed that concern.
“Please get the word out that people should not be driving,” Chip Dapolite said.
“Power lines are down all over the place. It may be sunny and beautiful, but please don’t drive.”
Throughout the storm, fire, police and DPW employees responded to reports of downed limbs, fallen trees and wires in the roadways.
At this time, Westborough officials continue to report live wires to electric companys crews.
Because of the high volume of downed wires, attempts are being made to prioritize dangerous situations.
On its website, NSTAR reports that 114,000 customers remain without power.
“While many of our customers will have power restored within the next 24 hours; due to the difficult driving conditions, downed trees and severe damage experienced on our system, we’re anticipating our power restoration effort will last into the work week.”
Hurricane Irene hit Atlantic beach of North Carolina and one man was killed outside his home this morning.
The man was hit by a tree limb that blew down while he was walking around his house this morning in a rural area of Nash County, where winds were roaring at more than 60 mph, county Emergency Management Director Brian Brantley told the Associated Press.
Hurricane Irene hit Atlantic Beach, Cape Fear and the Outer Banks of North Carolina with Category 1 winds and rain and made landfall in Nags Head, North Carolina.
Hurricane Irene hit Atlantic Beach, Cape Fear and the Outer Banks of North Carolina with Category 1 winds and rain and made landfall in Nags Head
The center of hurricane hit the coast of North Carolina near Cape Lookout with Category 1-force winds of 85 mph.
Hurricane warnings for the next 48 hours have been issued for North Carolina, Virginia, Washington, D.C., Maryland, Delaware, New York, Pennsylvania, New Jersey, coastal Connecticut, Rhode Island and Massachusetts.
Until now, eastern North Carolina has already seen three tornadoes in the past few days, and the majority of the state and areas of Maryland and Virginia are under tornado watches through Sunday.
Stacy town, on the coast of North Carolina, is seeing 93 mph wind gusts this morning.
The far end of the fishing pier in Atlantic Beach, North Carolina collapsed overnight.
The 100-foot long pier is still standing, but its end has disappeared into the ocean.
About 200,000 homes in North Carolina are experiencing power outages, according to Power Energy.
Winds up to 85 mph have ripped power lines from their poles, causing many of the shortages.
“Our crews are restoring service as quickly as possible, where it is safe to do so,” Power Energy tweeted.
The hardest hit areas were Wilmington and Wrightsville Beach, North Carolina.