Showing posts with label feedbacks. Show all posts
Showing posts with label feedbacks. Show all posts

Tuesday 1 April 2014

Earthquakes in the Arctic Ocean

Earthquakes in the Arctic Ocean
indications of immiment catastrophic methane eruptions?

1. Methane over Greenland

The image below shows high methane concentrations over Greenland and over the Arctic Ocean.

[ Yellow areas indicate methane readings of 1950 ppb and higher - click on image to enlarge ]
The large yellow areas on this image indicate that the methane entered the atmosphere there. This is especially likely when such large yellow areas keep appearing in the same area over a few days. In the case of the large yellow areas around Novaya Zemlya, the methane is likely to have travelled there underneath the sea ice, from the Gakkel Ridge, to enter the atmosphere where the sea ice was thin or fractured enough for the methane to pass through, as discussed in earlier posts.

As described in the post High methane readings over Greenland, huge temperature swings can hit areas over Greenland over the course of a few days. Temperature anomalies may go down as low as as -20°C one day, then climb as high as 20°C a few days laters, to hit temperature anomalies as low as -20°C again some days later.

This could explain the methane over Greenland. Methane is present in the Greenland ice sheet in the form of hydrates and free gas. These huge temperature swings are causing the ice to expand and contract, thus causing difference in pressure as well as temperature. The combined shock of wild pressure and temperature swings is causing movement and fractures in the ice, and this enables methane to rise to the surface and enter the atmosphere.

To further illustrate this, the image below shows recent temperature anomaly forecasts over Greenland.

[ click on image to enlarge ]
2. What is causing these extreme weather events?

Frigid cold weather in the U.S., torrential rain and flooding in the U.K., and wild temperature swings over Greenland. What is causing these extreme weather events? 

As discussed in many previous posts, the Arctic has become warmer than it used to be and temperatures in the Arctic are rising several times faster than global temperatures. This decreases the temperature difference between the areas to the north and to the south of the Jet Stream, which in turn decreases the speed at which the Jet Stream circumnavigates the globe, making the Jet Stream more wavier and increasing opportunities for cold air to descend from the Arctic and for warm air to enter the Arctic.

3. Did temperature swings also trigger earthquakes?

[ click on image to enlarge ]
These wild temperature swings may be causing even further damage, on top of the methane eruptions from the heights of Greenland. Look at the above map, showing earthquakes that hit the Arctic in March 2014.
Topographic map of Greenland
without the Greenland Ice Sheet.

BTW, above map doesn't show all earthquakes that occured in the Arctic Ocean in March 2014. An earthquake with a magnitude of 4.5 on the Richter scale hit the Gakkel Ridge on March 6, 2014.

Importantly, above map shows a number of earthquakes that occurred far away from faultlines, including a M4.6 earthquake that hit Baffin Bay and a M4.5 earthquake that hit the Labrador Sea. These earthquakes are unlikely to have resulted from movement in tectonic plates. Instead, temperature swings over Greenland may have triggered these events, by causing a succession of compression and expansion swings of the Greenland ice mass, which in turn caused pressure changes that were felt in the crust surrounding the Greenland Ice Sheet.

Glaciers could be the key to make this happen. Glaciers typically move smoothly and gradually. It could be, however, that such wide temperature swings are causing glaciers to come to a halt, temporarily, causing pressure to build up over a day or so, to then suddenly start moving again with a shock. Intense cold can literally freeze a glacier in its track, to be shocked into moving again as temperatures rise abruptly by 40°C or so. This can send shockwaves through the ice sheet into the crust and trigger earthquakes in areas prone to destabilization. The same mechanism could explain the high methane concentrations over the heights of Greenland and Antarctica.

Ominously, patterns of earthquakes can be indicators of bigger earthquakes yet to come.

4. Situation looks set to get a lot worse

This situation looks set to get a lot worse. Extreme weather events and wild temperature swings look set to become more likely to occur and hit Greenland with ever greater ferocity. Earthquakes could reveberate around the Arctic Ocean and destabilize methane held in the form of free gas and hydrates in sediments underneath the Arctic Ocean.

Meanwhile, as pollution clouds from North America move (due to the Coriolis Effect) over the Atlantic Ocean, the Gulf Stream continues to warm up and carry warmer water into the Arctic Ocean, further increasing the likelihood of methane eruptions from the Arctic seafloor.


The above image shows the Gulf Stream off the coast of North America, while the image below shows how the Gulf Stream continues, carrying warmer water through the Atlantic Ocean into the Arctic Ocean.


Feedbacks, such as the demise of the Arctic's snow and ice cover, further contribute to speed up the unfolding catastrophe. Methane eruptions from the seafloor of the Arctic Ocean have become especially noticable over the past half year. The big danger is that this will develop into runaway global warming, as discussed in the recent post Feedbacks in the Arctic.

Furthermore, as-yet-unknown feedbacks may start to kick in. As an example, submarine earthquakes and volcanos could add nutrients into the water that feed methane-producing (methanogenic) microbes. A recent study found that expansion of such microbes could have played a large role in the end-Permian extinction, and that it was catalyzed by increased availability of nickel associated with volcanism. Authors support their hypothesis with an analysis of carbon isotopic changes leading up to the extinction, phylogenetic analysis of methanogenic archaea, and measurements of nickel concentrations in South China sediments.

5. Need for comprehensive and effective action

The situation calls for comprehensive and effective action as discussed at the Climate Plan blog.





Related

- Methane Release caused by Earthquakes
http://arctic-news.blogspot.com/2013/09/methane-release-caused-by-earthquakes.html

- Seismic activity
http://arctic-news.blogspot.com/p/seismic-activity.html

- Climate Plan
http://climateplan.blogspot.com




Thursday 20 March 2014

Feedbacks in the Arctic

This is more a climate report than a weather report; yet, the extreme weather that did hit the U.K. recently and that is forecast to hit large parts of North America next week may make more people realize that action is needed now. So, please share!

At the moment, a large part of Russia is experiencing temperature anomalies at the highest end of the scale, i.e. more than 36°F (20°C) warmer than average past records.


Above image shows the situation as at March 20, 2014. The image below is a forecast for March 22, 2014.


Over the past year, average temperatures over the Arctic Ocean have been much higher than they used to be, as illustrated by the NOAA image below.

Warming in the Arctic is accelerating, in part due to a number of feedbacks such as extreme weather. Temperatures over the Arctic Ocean are expected to rise even further next week. The Arctic as a whole is expected to reach average anomalies as high as 5.3°C next week, while many areas over the Arctic Ocean are expected to be hit by even higher anomalies, as the image below shows.

 [ click on image to enlarge ]
Above image also shows that, at the same time, very low temperatures - with anomalies at the low end of the scale - are expected to hit a large part of North America. The image below shows what temperatures can be expected on March 26, 2014, 12:00 UTC.


As above image illustrates, temperatures over a large part of North America can be expected to be hardly higher than temperatures over the Arctic Ocean mid next week. It is this very difference between high altitude temperatures and lower altitude temperatures that drives the Jet Stream. In the absence of much difference, changes to the Jet Stream are making it easier for cold air to move out of the Arctic and for warm air from lower latitudes to move in. The Polar Vortex is similarly affected, as illustrated by the image below.


At lower altitude, the highest wind speed detected on the image below was 94 km/h (green marker). Strong winds brought a lot of rain from the Atlantic Ocean to the U.K., as has been the case for some time.

[ click on image to enlarge ]
The result is more extreme weather, which can translate into more intense storms, heatwaves, droughts, wildfires and further havoc. Importantly, storms across the Arctic Ocean and higher wind speeds along the edges of Greenland can break up the ice and speed up its exit from the Arctic Ocean. The Naval Research Laboratory animation below shows strong winds pushing the sea ice around and speeding up its exit along the edges of Greenland. 


Despite the cold weather that has hit large parts of North America over the past few months, the water off the coast of North America has not cooled, as illustrated by the image below. The blue and lilac colored areas are in part the result of exit currents carrying cold water out of the Arctic Ocean more rapidly, while the Gulf Stream continues to carry warmer water (brown and red colored areas) into the Arctic Ocean. 

[ Sea Surface Temperatures (SST) - click on image to enlarge ]
The Arctic is especially vulnerable to warming, due to a number of circumstances, including:
- Gulf Stream carrying warmer water into the Arctic Ocean;
- Arctic snow and ice cover is at the verge of collapse;
- Methane is present in large quantities under the seafloor of the Arctic Ocean.
These circumstances and the combined impact of feedbacks such as extreme weather make that, on top of global warming, the Arctic is hit by a second, addtional kind of warming, i.e. accelerating warming in the Arctic.

The joint impact of feedbacks is becoming stronger, as temperatures keep rising in the Arctic and with continued demise of the snow and ice cover. So, let's start with feedback #1, i.e. that, as snow and ice cover decline further, an ever larger part of the sunlight will be absorbed by the Arctic Ocean, rather than to (a) be reflected back into space or (b) be consumed in the process of transforming ice into water. This first feedback will then be amplified by further feedbacks such as storms that can more easily develop in open water. And, as the weather becomes more extreme, stronger storms and heatwaves can be expected to hit the Arctic Ocean, causing further demise of the sea ice, resulting in more heat being absorbed by the Arctic Ocean. Thus, feedbacks can amplify each other, causing warming in the Arctic to accelerate even further. 

One of the most dangerous feedbacks is that, as the Arctic Ocean warms up further and as the Gulf Stream carries ever warmer water into the Arctic Ocean, methane can erupt from the seafloor of the Arctic Ocean in large quantities. Methane eruptions from the seafloor of the Arctic Ocean have become especially noticable over the past half year. The big danger is that this will develop into a third kind of warming, runaway global warming. 

Large amounts of methane are still entering the atmosphere over the Arctic Ocean, which contains very little hydroxyl to start with, so large abrupt releases will deplete the little hydroxyl that is there much faster than elsewhere. Furthermore, the methane will initially be highly concentrated in the atmosphere over the Arctic Ocean, and where the methane does move out of the Arctic, it could warm up the water along the track of the Gulf Stream, causing even warmer water to enter the Arctic Ocean. For years after its release, the methane will act as a powerful greenhouse gas. Unlike the albedo changes, which have the highest impact at the June Solstice when the amount of solar radiation received by the Arctic is higher than anywhere else on Earth, methane prevents heat from radiating out into space throughout the year. 

The interactive diagram below gives an overview of these three kinds of warming and the numerous feedbacks that are accelerating warming in the Arctic, from the earlier post The Biggest Story of 2013.

Hover over each kind of warming and feedback to view more details, click to go to page with further background 
Image Mapemissions cause global warmingArctic warming accelerated by soot, etc.additional warming of Gulf Stream by emissions methane releases escalatePolar vortex and jet stream weaken as Arctic warmssnow and ice decline causing less sunlight to be reflected back into spacemethane releases warm Arctic airas sea ice decline weakens vertical currents, seabed warmsStorms cause vertical mixing of wateraccelerated Arctic warming causes storms that push cold air of the Arcticextreme weather causing storms that push away sea iceextreme weather causing storms that create higher waves, breaking up the sea icestorms creating more wavy waters that absorb more sunlightextreme weather causing fires, etc.weaker polar vortex and jet stream let cold air move out of Arcticextreme weather causing warmer waterssnow and ice decline cause seismic activity that destabilizes hydratesmethane releases prevent sea ice from forming

In conclusion, the situation is dire and calls for comprehensive and effective action, as described at the Climate Plan blog.




Related

- The Biggest Story of 2013
http://arctic-news.blogspot.com/2013/12/the-biggest-story-of-2013.html

- Climate Plan
http://climateplan.blogspot.com

- Changes to Polar Vortex affect mile-deep ocean circulation patterns
http://arctic-news.blogspot.com/2012/09/changes-to-polar-vortex-affect-mile-deep-ocean-circulation-patterns.html

- Diagram of Doom
http://arctic-news.blogspot.com/2012/08/diagram-of-doom.html

- Polar Jet Stream appears hugely deformed
http://arctic-news.blogspot.com/2012/12/polar-jet-stream-appears-hugely-deformed.html

- Methane Levels going through the Roof
http://arctic-news.blogspot.com/2013/11/methane-levels-going-through-the-roof.html

- Ocean heat: Four Hiroshima bombs a second: how we imagine climate change
http://arctic-news.blogspot.com/2013/08/four-hiroshima-bombs-second-how-we-imagine-climate-change.html

- (Three kinds of) Warming in the Arctic
http://arctic-news.blogspot.com/p/warming-in-arctic.html



Feedbacks
  1. Snow and ice decline causing more sunlight to be absorbed by the Arctic Ocean
    http://arctic-news.blogspot.com/2012/07/albedo-change-in-arctic.html
  2. Methane releases warming up Arctic air
    http://arctic-news.blogspot.com/2013/11/methane-levels-going-through-the-roof.html
  3. As sea ice decline weakens vertical currents, seabed warms
    http://arctic-news.blogspot.com/2012/09/arctic-sea-ice-loss-is-effectively-doubling-mankinds-contribution-to-global-warming.html
  4. Storms cause vertical mixing of water
    http://arctic-news.blogspot.com/2012/07/arctic-waters-are-heating-up.html
  5. Accelerated Arctic warming causes storms that push cold air of the Arctic
    http://arctic-news.blogspot.com/2012/08/diagram-of-doom.html
  6. Extreme weather causing storms that push away sea ice
    http://arctic-news.blogspot.com/2012/04/supplementary-evidence-by-prof-peter.html
  7. Extreme weather causing storms that create higher waves, breaking up the sea ice
    http://arctic-news.blogspot.com/2012/08/huge-cyclone-batters-arctic-sea-ice.html
  8. Storms creating more wavy waters that absorb more sunlight
    http://arctic-news.blogspot.com/2012/08/diagram-of-doom.html
  9. Extreme weather causing fires, etc.
    http://arctic-news.blogspot.com/2012/07/how-extreme-will-it-get.html
  10. Weaker polar vortex and jet stream let cold air move out of Arctic
    http://arctic-news.blogspot.com/2012/08/opening-further-doorways-to-doom.html
  11. Extreme weather causing warmer waters
    http://arctic-news.blogspot.com/2013/12/the-biggest-story-of-2013.html
  12. Snow and ice decline cause seismic activity that destabilizes hydrates
    http://arctic-news.blogspot.com/2013/09/methane-release-caused-by-earthquakes.html
  13. Methane releases prevent sea ice from forming
    http://arctic-news.blogspot.com/2013/12/methane-emerges-from-warmer-areas.html