Like a Volcano Slowly Awakening at the Top of our Earth: From Baffin Bay to the Laptev Sea, Arctic Methane Monster Releases Troubling Outbursts

The most dangerous of volcanoes have a number of identifiable behaviors.

They tend to lay dormant for hundreds, thousands, or tens of thousands of years. Then, slowly, as heat and pressure beneath the Earth builds, they begin to awaken. First they tremble a bit. Then they emit a growing volume of noxious gas. Then, they begin a series of mini-outbursts in an ever more violent build-up to an explosive and destructive grand eruption.

The lost residents of Pompeii, were they here today, could tell us what such an event is like.

Now consider that a volcano-like thing also exists beneath the world’s frozen oceans and lands near the roof of our world. A thing that probably hasn’t erupted in over 45 million years. A thing that has had this immense period of time in which to build up an enormous highly toxic and explosive reserve of frozen and sequestered methane. A thing that is at least as large as the boundary circumscribed by the Arctic Circle. A vast and extraordinarily dangerous monster of a thing. A kind of climate super-volcano.

AIRS_Methane

(Initial methane out-gassing shows a tell-tale methane overburden in the troposphere near Arctic ocean and tundra methane sources in 2011. Just one of many signs of what may be a very large, impending methane eruption. Image source: NASA/AIRS.)

For ever since the Earth began its long fall into cooling at the end of the Eocene, methane has been freezing at the bottom of the world’s oceans, sequestering in the frozen earth. As world land and ocean temperatures fell, the methane formed into clathrates or was bound up in organic permafrost and was, ever-after, locked away. There it lay patiently, waiting for the time when it would be, once again, disturbed by a return to warmth.

And that time of dangerous and explosive reawakening, increasingly, seems to be now.

Footprint of the Vast Volcanic Monster: Shallow Seas, Deep Seas, Permafrost

Of these volatile methane concentrations, some of the most prolific and the most vulnerable reside in the Arctic. Some, which lay sequestered within the shallow sea bed near the East Siberian Arctic Shelf, have been the subject of much controversy during recent years. Scientists like Natalia Shakhova and Peter Wadhams have issued repeated warnings that these methane stores could be vulnerable to a rapid release as sea ice retreats and waters warm. It is estimated that as much as 1400 gigatons of methane lay sequestered under Arctic submarine permafrost in the ESAS. A massive store that, if disturbed even in part, could provide an immense amplifying feedback to human-caused warming.

But the Arctic submarine permafrost isn’t the only zone in which large volumes of methane lay hidden. The Amundsen Basin, one of the deepest trenches in the Arctic Ocean, in the Laptev Sea is a known emitter of methane from sub-sea sources. A region near Svalbard both stores and emits large volumes of methane. And, recently, high rates of methane release have been observed near Baffin Bay. A complete catalog of these stores has not been adequately assessed. But, in combination, it is likely that they at least approach the total volume of stores in the vulnerable East Siberian Arctic Shelf (ESAS) zone.

Ominous Rumblings from the Rapidly Warming Deeps

These stores are deeper beneath the ocean surface and so are not generally thought to be as vulnerable as the shallow sea reserves in the ESAS. But this thinking may be in error as Arctic waters display a temperature inversion in which surface waters near the ice pack are colder than deeper waters far below.

In addition, wide zones of deep water in the Arctic have displayed rapid warming over the past few decades. As an example, bottom waters in the Greenland Sea, an area between the east coast of Greenland, Iceland and Svalbard, were shown in a September 2013 study to be warming 10 times faster than the rest of the world’s deep ocean system. According to the report:

Recent warming of the Greenland Sea Deep Water is about ten times higher than warming rates estimated for the global ocean. Scientists analyzed temperature data from 1950 to 2010 in the abyssal Greenland Sea, which is an ocean area located just to the south of the Arctic Ocean.

Deep Water Warming in Greenland Sea

(Deep Water Warming in the Greenland Sea since 1950. Image source: Science Daily. Image credit: Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research.)

In other regions of the Arctic and through the rest of the global ocean system rapid ocean bottom warming has also been observed. Recent studies by Kevin Trenberth have found that heat accumulation in the deep ocean, during recent years, has outpaced that of warming at or near the surface. And because this warming occurs adjacent to frozen methane stores on or beneath the sea floor, it is a very, very dangerous development.

To the point of an observed rapid warming of the deep ocean, it is important to note that there are a number of mechanisms that transport heat into the abyss worldwide. But in the Arctic, this transfer system is amplified and particularly intense. Fresh, cold surface waters tend to deflect warmer, saltier waters funneling in from more southerly latitudes toward the Arctic Ocean bottom. As glacial ice melts in Greenland, as storms within the Arctic intensify and become more prevalent, and as fresh water runoff from the continents surrounding the Arctic basin increases, fresh water content at the surface grows and widens, creating a kind of fresh water wedge that expands southward and deflects warmer, saltier water toward the ocean bottom.

And there, the warmer waters can go to work releasing the massive volumes of methane stored in frozen clathrates near the ocean floor.

Large Mid-February Methane Belch

Methane released from deep water clathrate stores has a long journey before it reaches the atmosphere. The methane passes through the water column, where a portion of it oxidizes into CO2. Microbes near the methane source and throughout the water column devour a portion of the methane as an energy source. But eventually, if the pulse is large enough, the methane finds its way to the surface and releases. Such outbursts are, likely, only a fraction of the initial bottom release. So a large expulsion into the atmosphere may well be a hint that something even more powerful and energetic is going on down below.

Over the past decade, deep water regions have shown at least as much atmospheric venting as the East Siberian Arctic Shelf. And this year has been no exception with troubling outbursts continuing in a zone from Baffin Bay to Svalbard to the Laptev Sea. These outbursts have, in part, contributed to increasing atmospheric methane concentrations at a rate of around 7 parts per billion each year since 2007 after an 8 year period during which global methane levels had plateaued at around 1790 parts per billion. By comparison, pre-industrial global methane levels were around 750 parts per billion during the 1880s. Today, they average around 1835 ppb (Mauna Loa). Should very large outbursts emerge, the rate of atmospheric methane increase would be expected to dramatically steepen. And though we haven’t yet seen these kinds of outbursts, more minor, but still large and concerning, continue to occur with troubling frequency.

This past week, according reports from Methane Tracker and Sam Carana, two particularly large and troubling ocean to atmosphere methane outbursts were observed in this region — one over the Laptev Sea and the other over Baffin Bay. The Baffin Bay outburst occurred in a zone where water depths ranged from 1,000 to 2,500 meters (middle to deep ocean) and the Laptev outburst likely occurred from the deep waters and precipitous slopes of the Amundsen Basin which plunges as deep as 4,400 meters (extraordinarily deep ocean) and extends almost directly under the North Pole.

Methane belch

(Methane belching from Laptev Sea and Baffin Bay on February 22nd with highest reading spiking to 2383 ppb, about 500 ppb above the global average. Image source: Methane Tracker and Sam Carana. Data source: composite methane data collection from SIO, NOAA ESRL, U.S. Navy, GEBCO. )

From these outbursts, 10,000 foot methane concentrations of 2383 ppb were observed. These readings are about 500 ppb higher than the global average and represent an extraordinary local spike for the Arctic.

The outbursts occurred in a region where the fresh water wedge was most recently active — areas where sea ice keeps expanding then melting and retreating as warmer, saltier waters encroach. Regions where the warmer water column would be continuously flushed toward ocean bottom zones containing methane hydrates.

If we were to continue with the volcano analogy, we could well consider the most recent Laptev and Baffin Bay outbursts to be a series of minor but intensifying eruptions. The most recent in a string of troubling and increasingly more volatile activity from the methane volcano rumbling at the top of our planet.

Links:

Deep Greenland Sea is Warming Faster than the World Ocean

Global Heating Accelerates, Deep Ocean Warming the Fastest, What Does it Mean for Methane Hydrates?

Methane Tracker

NOAA ESRL

Massive Methane Concentrations over Laptev Sea

2013 4th Hottest Year on Record, Deep Ocean Warming Fastest

Triggers to Release the Methane Monster, Deep Ocean Warming, Sea Ice Melt, Sea Level Rise and the Fresh Water Wedge

Methane Emissions From ESAS Occurring at Twice the Expected Rate

The Arctic Methane Monster Stirs

Beneath the Cracking, Melting Ice, The Arctic Methane Monster Continues it Ominous Rumblings

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Global Heating Accelerates, Deep Ocean Warming Fastest; What Does it Mean For Methane Hydrates?

A new study published in Geophysical Research Letters, found that ocean heat content rose at its fastest rate ever recorded over the past 15 years. The study, written by Magdalena A. Balmaseda, Kevin E. Trenberth, and Erland Kallen, found that the deep ocean below 700 meters accounted for 30% of all global heat content increase over the past decade.

What this means is that total warming of the atmosphere-ocean system didn’t slow down as some global warming denier sources claim. Instead, total Earth warming accelerated.

According to the paper, the most recent period since 1999 was:

the most sustained warming trend in this record of OHC. Indeed, recent warming rates of the waters below 700m appear to be unprecedented. In the last decade, about 30% of the warming has occurred below 700 m, contributing significantly to an acceleration of the warming trend.

Over the past decade, La Nina events have predominated. And this, according to study authors, resulted in a large portion of global warming being retained in the oceans. The reason is that El Nino is a powerful mechanism of ocean heat transfer to the atmosphere. But over the past decade, El Nino events have been rare, keeping more human caused heating in the world’s oceans. Not only did upper levels of the ocean heat up, a massive amount of global warming telegraphed into the deepest regions of world ocean systems.

According to Keven Trenberth, one of the study’s authors and a leading climate scientist, “It means less short term warming at the surface but at the expense of a greater earlier long-term warming, and faster sea level rise.”

The reason is that rapidly warming oceans pump more water vapor into the atmosphere. Water vapor is a powerful greenhouse gas and a major amplifying feedback to human caused warming. In addition, rapidly warming waters leads to greater thermal expansion of the world’s oceans, accelerating sea level rise.

Bad News For Methane Hydrates

More rapid ocean heating also has another impact not directly mentioned in the new study. What it does is put more of the world’s deposits of methane hydrates at risk of destabilization.

Methane hydrate is a volatile mixture of methane and frozen water that can be found on seabeds around the world. It is estimated that as much as 10,000 gigatons of carbon lay locked in methane hydrate deposits around the globe. Methane is a powerful greenhouse gas. Over a century, it is 20 times more powerful by volume than CO2. Over ten years, it is 100 times more potent. Methane is also problematic because after it amplifies warming as methane, it then breaks down into CO2, adding to already high volumes of that gas. Were even a small fraction of this carbon to bubble up from the ocean bottom and reach the atmosphere, it would result in a powerful amplifying feedback to human caused climate change.

Over the past decade, instances of methane hydrate destabilization have been found in the Arctic, off the east coast of the United States, and in other regions around the globe. Many of these events appeared to be new. Of these, methane plumes found in the East Siberian Arctic Shelf were the most disturbing. There, plumes of methane a kilometer across were discovered. Though submerged tundra was also a likely contributor to massive methane plumes discovered on the shelf, hydrates are also known to have formed there.

Now, with oceans heating at a greater rate than the atmosphere, risks for large methane hydrate releases are also increasing.

Most Missing Heat Found, Look to Ice Sheets for Remainder

This new research finds most of the missing heat scientists have been looking for around the globe. And that heat, as previously suspected, ended up in the world’s oceans and, to great extent, in the deep oceans. That said, a much smaller measure of heat is still unaccounted for. It might not be a bad idea to look in the world’s ice sheets — which appear to be decaying at a much faster rate than expected. One speculates that the hearts of the great glaciers are more watery than anticipated and contain much of the remaining heat from human caused global warming not currently located.

Links:

In Hot Water: Global Warming Has Accelerated Over Past 15 Years, New Study of Oceans Confirms

Winter 2013 Shows Increasing Arctic Methane Feedback to Human Caused Warming

Oceans Sponging Up Warmth

Arctic Methane Release Sea Ice Melt Shows Amplifying Feedbacks to Human Caused Climate Change

 

Top Scientists Speak Out On Growing Risk of Methane Emergency

With the Arctic warming so rapidly, risk of a large methane release is a considerable and growing problem. Estimates are that more than 2,000 gigatons of the stuff lay trapped in northern hemisphere permafrost or locked in methane stores called clathrates on the bottom of the shallow Arctic Ocean. As human caused climate change drives rapid sea ice retreat, the ocean warms and mechanical action mixes the water, transporting more and more heat down to the seabed, destabilizing the frozen methane. As the snow line retreats in the warming climate, more permafrost is also laid bear, amplifying the release of land-based methane stores.

On the East Siberian Arctic shelf, a vulnerable region of the Arctic Ocean, perhaps 500 gigatons of methane and methane clathrate rest on or just beneath the sea bed. If just 1% of the  methane store in this single region were released, atmospheric methane would double.

Over the past few years, growing evidence has been accumulated that methane emissions from the Arctic permafrost and seabed are increasing. The East Siberian Arctic shelf produced vast methane emitting formations as large as 1 kilometer in diameter during 2011. Such releases are a potential sign of growing destabilization in the region. And since any major release of Arctic methane would provide a catastrophic amplifying feedback to human caused global warming, concern is growing that we are at increasing risk for just such an event.

In the above video, James Hansen, head of NASA’s GISS division, Natalia Shakhova, a scientist at the International Arctic Research Center, Peter Wadhams, a Professor at Cambridge and resident Arctic sea ice expert, and David Wasdell, a prominent environmentalist, discuss the dangers of Arctic methane release. Hansen and Wadhams are both very heavy hitters and bear listening to. Shakhova is doing cutting-edge research in the field and serves as a witness to the dangerous trend that is unfolding. And Wasdell rounds the discussion out by providing the ecological and climate context in which a large methane release may occur.

The problem is certainly very, very serious and we urgently need to reduce carbon emissions to reduce the risk of a large and catastrophic release.

To follow atmospheric methane, take a look at NOAA’s carbon gasses tracker at Barrow Alaska (CO2, methane, CFCs, etc):

http://www.esrl.noaa.gov/gmd/dv/iadv/graph.php?code=BRW&program=ccgg&type=ts

Links:

https://robertscribbler.wordpress.com/2012/10/26/human-co2-emissions-continue-to-play-russian-roulette-with-clathrate-gun-new-study-shows-east-coast-hydrates-destabilizing/

http://neven1.typepad.com/blog/

http://neven1.typepad.com/files/overshooting-limits-gwj.doc

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