High Methane Readings continue over Depth of Arctic Ocean

The image below contains 12 frames, with methane readings recorded over 12 days in the first half of October 2013.

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As discussed in earlier posts at this blog, high methane readings have been recorded recently over the depth of Arctic Ocean. Above image shows that these high readings are continuing. The image below shows that at 469 mb, the altitude at which the highest reading was recorded on the afternoon of October 13, methane shows up very prominently over the Arctic Ocean.

The fact that little methane shows up elsewhere indicates that methane is present at high levels, at times over 2200 ppb, over the depth of the Arctic Ocean, and that these high levels result from methane that originates from hydrates under the seabed.

The image below, with methane readings over the past few days (from October 12 10:00 pm to October 14 11:23 pm), shows high levels of methane over the depth of the Arctic Ocean.

The image below shows methane readings at 586 mb, the altitude at which the highest methane reading was recorded on the afternoon of October 14 (a reading of 2248 ppb). Again, methane is present very prominently over the depth of the Arctic Ocean.

Post by Sam Carana.

 

Methane over deep waters of Arctic Ocean

The image below shows a lot of methane over deeper parts of oceans, in particular the Arctic Ocean.

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Let's zoom in and take a closer look at what's happening.

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As earlier discussed in the post Methane release caused by earthquakes, there has been a lot of seismic activity in the Aleutian Islands region all the way up into Alaska, including an earthquake with a magnitude of 7 on the Richter scale on August 30, 2013, and several more recent earthquakes with a higher magnitude than 6 on the Richter scale.

An earthquake with a magnitude of 4.6 on the Richter scale hit the Laptev Sea on September 28, 2013. Furthermore, there have been several earthquakes in Siberia, while an earthquake with a magnitude of 6.7 on the Richter scale recently hit the Sea of Okhotsk, which occurred at a depth of 359.3 miles (578.24 km). Earthquakes at such a depth can be felt at great distances from the epicenter and can destabilize methane hydrates.

The presence of methane over the deeper parts of the Arctic Ocean has been discussed in a number of post at this blog recently (see under related, below). It should serve as a warning to those who believed that all methane escaping from deep-sea hydrates would be oxidized in the water by microbes before entering the atmosphere.

The IPCC appears to still close its eyes for such scenarios. Look at this screenshot from IPCC AR5 WGI TS.3.7:

Low release this century? Well, the danger may seem low now in many places, but the situation is already very dangerous in the Arctic, where hydroxyl levels in the atmosphere are very low, where water temperatures can show huge anomalies and where seas can be very shallow and at times become super-saturated with methane, to the extent that oxygen depletion in the water prevents methane oxidation. In the case of large abrupt release, waters will soon become super-saturated with methane locally, especially in the shallow parts of the Arctic Ocean. Furthermore, low sea temperatures and the peculiarities of currents create conditions in the Arctic Ocean that are not beneficial to the kind of growth of microbes that would decompose methane in oceans elsewhere.

How much methane are we talking about? One look at the top image shows that there's a huge amount of methane over the Arctic Ocean. On October 3, 2013, a peak reading was recorded of 2283 ppb and that wasn't even the highest recent reading, as illustrated by the graph below.

Where were these large amounts of methane released? The animation below shows methane methane readings of over 1950 ppb on October 3, 2013, on the afternoon only and with readings at only four relatively low altitudes, with methane over the Arctic Ocean dominating the picture.