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.
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. Once methane reaches the atmosphere, it can very rapidly raise local temperatures, further aggravating the situation.
Arctic sea ice is already in a very bad shape. The Naval Research Laboratory nowcast below shows that sea ice thickness has fallen dramatically recently.
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 temperature rise will be felt firstly and most strongly in the Arctic.
To illustrate the danger, the image on the right shows smoke arising from wildfires on Siberia, while the image below shows that, on July 18, 2016, levels of carbon monoxide (CO) over Siberia were as high as 32318 ppb, and in an area with CO2 levels as low as 345 ppm, carbon dioxide (CO2) reached levels as high as 650 ppm.
|[ click on images to enlarge them ]|
The image below, from the MetOp satellite, shows high methane levels over Siberia on July 21, 2016.
The image below shows methane levels at Barrow, Alaska.
The image below shows that, while methane levels may appear to have remained stable over the past year when taking measurements at ground level, at higher altitudes they have risen strongly.
The conversion table below shows the altitude equivalents in feet, m and mb.
|57016 feet||44690 feet||36850 feet||30570 feet||25544 feet||19820 feet||14385 feet||8368 feet||1916 feet|
|17378 m||13621 m||11232 m||9318 m||7786 m||6041 m||4384 m||2551 m||584 m|
|74 mb||147 mb||218 mb||293 mb||367 mb||469 mb||586 mb||742 mb||945 mb|
The situation is dire and calls for comprehensive and effective action, as described at the Climate Plan.