---------- Forwarded message ---------- From: "Doly Garcia" <[email protected]> Date: Feb 2, 2013 11:15 PM Subject: Two relevant papers on methane hydrates To: (deleted)
> See here the abstract of an interesting study pointing out to methane hydrate releases during the Paleocene-Eocene Thermal Maximum: > > > > http://www.sciencedirect.com/science/article/pii/S0025322712002332 > > > > Unfortunately, I have lost my University of Brighton access (currently negotiating with them on the basis that I’m interested in doing a PhD with them) so I can’t get access to the full article. > > > > I find particularly interesting the last sentence of the abstract: Volume calculations indicate that the amount of gas released in our study area is two orders of magnitude lower than what would be needed to trigger the Paleocene–Eocene Thermal Maximum event suggesting that the anomalies are rather developed as a consequence of global hyperthermal events. > > > > In other words, global warming events may trigger methane hydrate releases, but not in sufficient amounts to create a significant feedback effect. This supports what David Archer said that during the last interglacials, methane hydrates had remained mostly stable. > > > > Another paper on the stability of methane hydrates can be found (in full) here: > > > > http://www.researchgate.net/publication/232659054_Variations_in_BSR_depth_due_to_gas_hydrate_stability_versus_pore_pressure/file/d912f5089286169411.pdf > > A particularly interesting sentence in the conclusions: Our study points out that the Polar Regions are most sensitive to the overpressure conditions from the hydrate point of view. In fact, in the case 3A characterized by low sea bottom temperature, low overpressure condition in the pore space in the free gas influences the hydrate stability at shallow water, where the effect of the climate change is more important, as already pointed out recently by several authors. > > > > The study makes clear that these are areas where methane hydrates are expected to be in metastable conditions, extraordinarily sensitive to changes in environmental conditions. On the other hand, the amount of methane hydrates in such metastable conditions in the world is low in comparison to the total amount of methane hydrates. (Unsurprisingly, since most of the methane hydrates in a metastable condition will have been released already). This again fits with the idea that, in the greater scheme of things, methane hydrates don’t play a big part in global warming events. > > > > Best regards, > > > > Doly > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
