Sentences with phrase «biogenic methane»

Gray areas represent the typical range of thermogenic and biogenic methane taken from Osborn and Mcintosh (18).

Gray areas represent typical ranges of thermogenic and biogenic methane (data from Osborn and McIntosh, ref.

The general trend from 100 BCE to the year 1600 shows a correlation between the increase in the appropriation of land for cultivation and the emission of the biogenic methane.

And as the following study explains could help explain the observed large increase of biogenic methane — which can occur in anaerobic environments.

Using correlations between concentrations of CH4 and carbon monoxide (CO) we estimated total emissions of 30.8 Tg CH4 during the 2008 monsoon season (June — September), 19.7 Tg of which were identified as additional, monsoon - related biogenic methane using the relationship of CH4 to ethane (C2H6).

Detailed studies at the State Hydrology Institute in St. Petersburg allow one to assume that biogenic methane emission in the Russian permafrost zone can not increase by more than 20 %, or at the most 30 %, compared to the current level, which would cause global warming by 0.01 degrees Celsius by 2050.

«A 21st - Century Shift from Fossil - Fuel to Biogenic Methane Emissions Indicated by 13CH4.»

Re: # 9, David, here are a few references on biogenic methane and its sorption in shales and coals.

The results of the two seem to be similar on one end of the spectrum, in that biogenic methane -LRB--60 o / oo) requires about 1000 Gt C.

Proposed hypothe - ses include (i) biogenic methane from gas hydrate dissociation (Dickens et al., 1995,1997); (ii) CO2 from extensive oxidation terrestrial organic carbon (Kurtz et al., 2003; Deconto et al., 2012); (iii) thermogenic methane derived from emplacement of a large 25 igneous province (LIP) in the North Atlantic (Svensen et al., 2010) or combinations of such sources (Sluijs et al., 2007; Panchuk et al., 2008).

Martini, A. M., L. M. Walter, J. M. Budai, T. C. W. Ku, C. J. Kaiser, and M. Schoell, 1998, Genetic and temporal relations between formation waters and biogenic methane: Upper Devonian Antrim Shale, Michigan basin, USA: Geochimica et Cosmochimica Acta, v. 62, p. 16991720.

Kirk Smith's reply to Graham Faichney's well - reasoned letter about the place of biogenic methane in the carbon cycle, and hence...

The team discovered that the human impact on biogenic methane and nitrous oxide emissions far outweighed the human impact on the terrestrial uptake of carbon dioxide, meaning that humans have caused the terrestrial biosphere to further contribute to warming.

The conclusion of the authors: The warming climate triggers not only the natural production of biogenic methane, it can also lead to stronger emissions of fossil gas.

Not exact matches

The main body has been divided into sections dealing with the three major biogenic GHGs including a section concerning carbon dioxide (CO2) emissions and photosynthetic absorption and a section that deals with nitrous oxide (N20), and methane (CH4) emissions (and assimilation in some limited cases).

Such model included meteorological factors like levels of aerosols, anthropogenic and biogenic volatile organic compounds (VOCs), ozone, carbon dioxide, methane, and other items that influence global temperature — the surface albedo among them.

The scientists first added up all biogenic emissions of carbon dioxide, methane, and nitrous oxide, then subtracted out those that occurred naturally prior to human intervention to get to the net amount.

Reading their paper it is easily seen that their conclusion is not convincing because their experimental strategy lacks and fails some simple tests to exclude or include known biogenic sources of methane.

Nor do we adequately understand the relative contributions of microbes (i.e., biogenic methanogenesis), fossil sources, and the dissociation of gas hydrates (an ice - like substance formed by methane and water under pressure).

Preliminary results using carbon dioxide, methane, carbon monoxide, ethane, and soot spectroscopy observations are teasing apart biogenic and thermogenic (i.e., biomass burning and oil and gas production) contributions.

The probability of this kind of methane migration is a function of the number of holes drilled through aquifers into gas bearing zones (both biogenic and thermogenic) and the imperfection of measures to control the upward rush of methane using cement casings to seal off the aquifers — a process that is faulty six percent of the time and more frequently as casings deteriorate with time.

Based on carbon isotope analyses the methane is of biogenic origin.

«We show that methane mixing ratios greater than 10 - 3 are potentially biogenic, whereas those exceeding 10 - 2 are likely biogenic due to the difficulty in maintaining large abiotic methane fluxes to support high methane levels in anoxic atmospheres,» the researchers wrote in their study.

[13][citation needed] The methane in clathrates typically has a biogenic isotopic signature and highly variable δ13C (− 40 to − 100 ‰), with an approximate average of about − 65 ‰.

For the timescale of climate change, perhaps only the prevalence of biogenic gas (methane) as clathrates in permafrost or the cold bottom water sediments represent a significant contributor to catastrophic climate change.

Understanding the origin of this methane, whether it is shallower biogenic or deeper thermogenic gas, is therefore important for identifying the source of contamination in shallow groundwater systems.

S2) are consistent with a deeper thermogenic methane source at the active sites and a more biogenic or mixed methane source for the lower - concentration samples from nonactive sites (based on the definition of Schoell, ref.

High methane concentrations in well - ice - bonded sediments and gas releases suggest that pore - space hydrate may be found at depths as shallow as 119 m. Geochemical and isotopic determinations suggest that the methane hydrate observed in the core hole is biogenic (microbial) in origin.