Monday, 18 July 2016

High methane levels in Arctic

High Methane Levels Follow Earthquake in Arctic Ocean

17 July, 2016

In the 12 months up to July 14, 2016, 48 earthquakes with a magnitude of 4 or higher on the Richter scale hit the map area of the image below, mostly at a depth of 10 km (6.214 miles).

As temperatures keep rising and as melting of glaciers keeps taking away weight from the surface of Greenland, isostatic rebound can increasingly trigger earthquakes around Greenland, and in particular on the faultline that crosses the Arctic Ocean.

Two earthquakes recently hit the Arctic Ocean. One earthquake hit with a magnitude of 4.5 on the Richter scale on July 9, 2016. The other earthquake hit with a magnitude of 4.7 on the Richter scale on July 12, 2016, at 00:15:24 UTC, with the epicenter at 81.626°N 2.315°W and at a depth of 10.0 km (6.214 miles), as illustrated by the image below.

Following that most recent earthquake, high levels of methane showed up in the atmosphere on July 15, 2016, over that very area where the earthquake hit, as illustrated by the image below.

Above image shows that methane levels were as high as 2505 ppb at an altitude of 4,116 km or 13,504 ft on the morning of July 15, 2016. At a higher altitude (of 6,041 km or 19,820 ft), methane levels as high as 2598 ppb were recorded that morning and the magenta-colored area east of the north-east point of Greenland (inset) looks much the same on the images in between those altitudes. All this indicates that the earthquake did cause destabilization of methane hydrates contained in sediments in that area.

The image on the right shows glaciers on Greenland and sea ice near Greenland and Svalbard on July 15, 2016. Note that clouds partly obscure the extent of the sea ice decline.

In addition to the shocks and pressure changes caused by earthquakes, methane hydrate destabilization can be triggered by ocean heat reaching the seafloor of the Arctic Ocean.

As discussed in an 
earlier post, as temperatures keep rising, some 1.6°C or 2.88°F warming due to albedo changes (i.e. decline both of Arctic sea ice and of snow and ice cover on land) and some 1.1°C or 2°F temperature rise due to methane releases from clathrates at the seafloor of the world's oceans seems well possible by the year 2026.

The situation is dire and

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