Hundreds of Methane Plumes Erupting Along East Coast
"We
don't know of any explanation that fits as well as methane," said lead
study author Adam Skarke, a geologist at Mississippi State University in
Mississippi State. Between North Carolina's Cape Hatteras and
Massachusetts' Georges Bank, 570 methane seeps cluster in about eight
regions, according…
Hundreds of Methane Plumes Erupting Along East Coast
By Becky Oskin, Senior Writer
20 hours ago
A close-up of methane hydrate observed at a depth of 3,460 feet (1,055 meters) off the U.S. Atlantic …
In an unexpected
discovery, hundreds of gas plumes bubbling up from the seafloor were
spotted during a sweeping survey of the U.S. Atlantic Coast.
Even though ocean explorers have yet to test the gas, the bubbles are almost certainly methane, researchers report today (Aug. 24) in the journal Nature Geoscience.
"We don't know of any explanation that fits as well as methane," said
lead study author Adam Skarke, a geologist at Mississippi State
University in Mississippi State.Surprising seeps
Between North Carolina's Cape Hatteras and Massachusetts' Georges Bank, 570 methane seeps
cluster in about eight regions, according to sonar and video gathered
by the National Oceanographic and Atmospheric Administration ship
Okeanos Explorer between 2011 and 2013. The vast majority of the seeps
dot the continental slope break, where the seafloor topography swoops
down toward the Atlantic Ocean basin. [Gallery: Amazing images of Atlantic Methane Seeps]
The Okeanos Explorer used sound waves to detect the methane bubbles and
map the seafloor. The technique, called multibeam sonar, calculates the
time and distance it takes for sound waves to travel from the ship to
the seafloor and back. The sonar can also detect the density contrast
between gas bubbles and seawater.
Huge canyons etched in the
shallow continental shelf also hide bubble plumes, as well as diverse
ecosystems that are based on methane-loving bacteria. In 2013,
researchers explored a handful of these seeps with Jason, a remotely
operated vehicle, finding them teeming with crabs, fish and mussel beds.
In Norfolk canyon off the coast of Virginia, researchers from the
University of North Carolina at Wilmington discovered the largest methane seep ever found in the Atlantic Ocean, and possibly all the world's oceans. [Photos: Unique Life Found at East Coast Gas Seep]
Most of the methane seeps are in water less than 1,640 feet (500
meters) deep. Most of these shallow methane seeps seem to arise from
microbes blurping out methane, the researchers said. The researchers did
find some deeper methane vents, at which the ROV Jason glimpsed patches
of methane hydrate. This is the icy mix of methane and water that
appears when deep ocean pressures and cold temperatures force methane to
solidify. Any type of methane gas can form hydrates.
While
methane vents are common around the world, only three natural gas seeps —
where methane escapes from seafloor sediments — had been found off the
East Coast before 2012.
"It
was a surprise to find these features," Skarke said. "It was unexpected
because many of the common things associated with methane gas do not
exist on the Atlantic margin."
Gas, gas, gas?
The East Coast is a
passive margin, and methane isn't expected to come out of this
environment. The margin hasn't been squeezed or pulled by plate tectonic
activity for tens of millions of years, and that means a lack of escape
routes for methane. "I usually describe passive margins as cold, old
and boring," said study co-author Carolyn Ruppel, chief of the U.S.
Geological Survey gas hydrates project in Woods Hole, Massachusetts. [In Images: How North America Grew as a Continent]
Also missing from the Atlantic Coast are layers of salt, which are responsible for the Gulf of Mexico's oil and gas.Without more exploring, the researchers can't say for sure why there are so many methane plumes along the Atlantic coastline. "It's a huge research area that needs to be pursued," Ruppel said.
If the East Coast could hide hundreds of bubbling methane pits, then
it's likely there are nearly 30,000 more awaiting discovery in the
world's oceans, the researchers said.
"These processes may be happening in places we didn't expect them," Skarke said.There's also a good chance more methane vents will be found off the East Coast, but that doesn't mean one should expect new drilling platforms popping up offshore to extract the gas, the researchers said. "We have no evidence to suggest this material would be a recoverable resource," Skarke told Live Science. "There is no evidence whatsoever that there are conventional deep-seated oil and gas reservoirs underneath the Atlantic margin."
The more likely scenario: A fleet of research ships hurries to claim the seeps. The methane seeps are near ports where many of the U.S. research ships dock. The ease of access has set off an exploration stampede, with several new projects in planning stages or already funded.
"We're setting the stage for a decade of discovery," Ruppel said.
From the Arctic to Atlantic
Interest is running high because the seeps could be a laboratory for studying how methane hydrates respond to climate change.
Methane is a greenhouse gas that disappears more quickly than carbon dioxide in the atmosphere, but has more warming power than carbon dioxide. Millions of tons of methane are frozen in Arctic permafrost, both on land and in the seafloor. Recently, several studies have warned that rapid warming in the Arctic could upset these deposits, melting them and freeing the gas. This would boost the planet's greenhouse gas levels and could accelerate climate change.
"Now we have a study site where we can monitor these locations and see how they change," said David Valentine, a geochemist at the University of California, Santa Barbara, who was not involved in the study. "Finally we have a place where we can begin to address some of the questions about how water temperatures are influencing methane."
At present, scientists think the East Coast seeps don't contribute much methane to climate change.
Most of the methane gas dissolves in the ocean before reaching the
surface, Ruppel said. The total amount of gas is also much smaller than
sources on land, such as cows or gas drilling. "It's probably on the
order of a feedlot of methane," Valentine said. However, some
shallow-water seeps could vent methane to the surface, and researchers
expect that future surveys will uncover even more shallow seeps. These
regions only received a cursory look during the survey.
Even though the methane may not escape to the atmosphere, the gas still
adds to the ocean's overall carbon budget — which is still a wildly
uncertain number.
"It's not a huge number, but it's an important number for us to know," Ruppel said.
Email Becky Oskin or follow her @beckyoskin. Follow us @livescience, Facebook & Google+. Original article on Live Science.
Hundreds of Methane Plumes Erupting Along East Coast
So, if I'm understanding this right Methane Hydrate is melting at deeper than 3000 feet from an ice form and breaking the surface of the water. However, then methane tends to go up and change the nature of the atmosphere.
The methane hydrate ice melting is similar to what happens in the arctic but if you are 3000 plus feet beneath the ocean some of the conditions are like the arctic at that depth.
Arctic methane release - Wikipedia, the free encyclopedia
en.wikipedia.org/wiki/Arctic_methane_release
They conclude that "release of up to 50 Gt of predicted amount of hydrate storage [is] ... Melting of this ice may release large quantities of methane, a powerful ...
Wikipedia
Atmospheric methane - Wikipedia, the free encyclopedia
en.wikipedia.org/wiki/Atmospheric_methaneAtmospheric methane is the methane present in Earth's atmosphere. Atmospheric methane concentrations are of interest due to methane's impact on climate ...WikipediaMethane Emissions | Climate Change | US EPA
epa.gov/.../ch4.htmlNatural processes in soil and chemical reactions in the atmosphere help remove CH4 from the atmosphere. Methane's lifetime in the atmosphere is much ...United States Environmental Protection Agency-
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Why Is There More Methane in the Atmosphere? - Scientific ...
www.scientificamerican.com › ... › ClimatewireJan 31, 2014 - In 2006, the scientists who monitor methane, a greenhouse gas about ... methane has been on the rebound, with atmospheric concentrations ...Scientific American-
- NBCNews.com - 11 hours agoMethane appears to be bubbling up from more than 500 vents on the Atlantic Ocean floor off the U.S. East Coast, according to a new study in a ...
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The Role of Methane - Earthguide
earthguide.ucsd.edu/.../03_3.shtmlThe amount of methane in the atmosphere has more than doubled over the last 200 years, according to ice core data. Adding methane to the atmosphere is ...University of California, San Diego- [PDF]
Climate science of methane - Environmental Change Institute
www.eci.ox.ac.uk/.../methaneuk/chapter0...2.1 Introduction. Methane is the most abundant reactive trace gas in the atmosphere and arises from both natural and anthropogenic sources. It is a valuable gas.Environmental Change Institute NASA GISS: Research Features: Methane: A Scientific ...
www.giss.nasa.gov/.../200409_metha...The first, by Wei-Chyung Wang and colleagues at NASA GISS in 1976, was that methane in the atmosphere was actually a significant greenhouse gas — it ...Goddard Institute for Space StudiesAtmospheric Methane Has Hit Record Levels, and It's Not ...
motherboard.vice.com/.../atmospheric-methane-has-hit-record-levels...Jan 31, 2014 - Methane is a gas that climate scientists would love to target. Unlike carbon, which can persist in the atmosphere for hundreds or thousands of ...ViceMethane - Think Global Green
www.thinkglobalgreen.org/METHANE.htmlThere is much less methane in the atmosphere than CO2: about 1800 parts per billion (ppb), compared with an estimated 390 parts per million of CO2. However...
- Atmospheric methane
- Atmospheric methane is the methane present in Earth's atmosphere. Atmospheric methane concentrations are of interest due to methane's impact on climate change, as it is one of the most potent greenhouse gases in Earth's atmosphere. Wikipedia
- Related topicsMethane clathrates are also present in deep Antarctic ice cores, and record a history of atmospheric methane concentrations, dating to 800,000 years ago. princeton.eduExplore: Methane clathrate, Ice coreMethanogens are the primary source of atmospheric methane, and are responsible for most of the world's yearly methane emissions. WikipediaExplore: MethanogenThe most effective sink of atmospheric methane is the hydroxyl radical in the troposphere, or the lowest portion of Earth's atmosphere. WikipediaExplore: Carbon sink
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