I want to repost the main reply to Sam as I have realized it is loaded with typos and some may be misleading.
That post was impressive, Sam. I have an 18 acre mountain lake in the North Cascades and watch each year how it goes though an analogy of what the Huttunen paper describes. The lake has a bog at one end and is rather shallow throughout. So, it constantly produces methane. The lake, in the past, has produced a brown bog-born algae bloom (low pH water) and I cured it with half a bag of yard lime spread evenly around the 18 acres. The O2 level drop significantly in the summer and so I have been studying the best ways to oxygenate. This general issue is not "academic" for me, it exists right out my back door and I have studied it extensively. Mixer or bubbles? We will need both and possibly a third option. If I ever go into surgery, I hope the doctor brings more than one scalpel....whether he needs it or not! I will outline an advanced third option concept in a later post. Testing, yes,it is important and I don't think any option should be blown out of the water without testing.....testing is relatively cheap for this concept! I could test any method here at my lake, but, using a world-class aquarium would be better. Or, best, we can use a well-studied ocean site such as the Hydrate Ridge (HR) in the Cascadia convergent margin. This proposed field test can be a short wave test which would have no significant environmental impacts beyond the test. The HR also provides a wide range of different types of vent conditions and biotic layers. "On the one hand, adding oxygen bubbles seems beneficial, given the need for oxidation of methane in the water. Also - as John Nissen said elsewhere - bubbles could form an insulating layer in between an ice-cap and warming water underneath the cap. Thirdly, bubbles could brighten the water, changing albedo and thus reflecting more sunlight back into space." Thanks for bringing up these second order, yet very important aspects. Microbubble/albedo has already been put through the ringer on this forum and I believe it has a reasonable place here. The big issue was not whether it would be effective, but, how can it be deployed. A Methane powered buoy network deploying hydrosols seems like a reasonable approach...to me! Think about the possibility of having the hydrosol equivalent of ice coverage (albedo) in the hot spots pointed out in the Berkeley paper.......during the summer. Initial real world deployment, which is highly focused upon those hot spots, would be ideal. And, we already have the computer models to work with! Thank you, Berkeley. "On the other hand, though, bubbles could disturb a hydrate and accelerate release of methane. Rising bubbles could take more methane along upwards than they help oxidize. Testing could reveal what impact can be expected."The avoidance of oxygenation of the seabed is a point I pointed out in the original post. I realized the importance of maintaining the biotic layer by oxygenating well above the floor and this also prevents disturbing the actual deposits. If you go back to the lecture, it demonstrates how fragile hydrates are and how quickly it decomposes once disturbed. "take more methane along..than help oxidize".....I can not find the lab video from Seitz's work right now, however, I would like to reference it here as a visual aide to address this point. In that, hydrosols do not act as a "normal" bubble do. They tend to have long residency time in the water column. Microbubbles, if assimilated by the larger methane bubbles, would be directly injecting O2 into the larger methane bubble. Whereas, the methane bubble, on its own, is only being oxidized through its surfactant outer film. I believe any test along these lines will show a significant oxidation rate increase due to this process of hydrosol assimilation within the methane bubble. Using pure O2 hydrosols would enhance this. I missed one of your points, an important one. 'bubbles could form an insulating layer in between an ice-cap and warming water underneath the cap". An oxygen enriched gaseous layer could help the surface biota thrive under the ice....more methane oxidation! > Thanks again, Sam. This type of input/questioning is important. Those links are top order information for this effort. Michael > > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
