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Fri Sep 6, 2019, 05:25 PM

Evaluating the Leak Potential of Giant Fossil Fuel Waste Dumps by Modeling Undersea Vents.

The paper I'll discuss in this post is this one: Simulating and Quantifying Multiple Natural Subsea CO2 Seeps at Panarea Island (Aeolian Islands, Italy) as a Proxy for Potential Leakage from Subseabed Carbon Storage Sites.

The cult of anti-nukes can be quite Trumpian in its pride in it's ignorance and overt hypocrisy.

For example, in the United States, over half a century, the United States has accumulated about 75,000 tons of used nuclear fuel in over half a century of operations. If one is unfortunate enough to engage one of these blunderbuss airheads, one can learn that, having learned to be terrified of radioactive atoms while getting a "C" in their 8th grade science classes, they believe that it is impossible to contain this fuel indefinitely.

Nevertheless, these same people will be perfectly OK with embracing the notion that one could - for them the word "could" is equivalent to "is" - contain 35 billion tons of dangerous fossil fuel waste - generated not over half a century but annually indefinitely.

Of course, they don't call these containment sites "dumps" - since it is their habit to misuse language (they probably got "C's" in 8th grade English as well - they call them "sequestration sites."

Since they're not very good at counting, or thinking and because they have a bourgeois disposable mentality, they think in terms of dumps; but let's be clear, every "dump" is dumped on all future generations.

The planet is not a single use container to be trashed by poorly educated bourgeois airheads. It is, rather, a magnificent, rare and sacred place in a largely unconscious universe.

The nation of Norway has gotten very upset about some technetium atoms in the North Sea. Technetium is a very useful and interesting metal that is radioactive in all of its forms and is a fission product from the production of nuclear energy. Regrettably some of it has been dumped rather than used. Hopefully that sort of thing will come to an end.

At no place in North Sea, despite the protests from Norwegians, is the concentration of technetium any where near what it is in the urine of a person recently having undergone a technetium based diagnostic imagining process designed to save their lives, but, no matter.

Norway has made a mountain of money by drilling for oil and gas in the same North Sea in which the Technetium that so upsets them is found.

And just so you don't think they're bad guys and gals, they built a waste dump for the stuff that their product turns into after its used, carbon dioxide. ...A small dump...a, um, "practice" dump...

Of course, these days people literally drop dead in the street from unprecedented high temperatures, or are killed by extreme weather events. Mention this fact to an anti-nuke or the related fact that seven million people die every year from air pollution - that would be 19,000 people today, and I'll bet they'll mutter some idiot chant about Fukushima or Chernobyl, as if these mattered on the scale of the destruction of the entire planetary atmosphere.

Anyway, about the Norwegian dangerous fossil fuel waste dump, here's some stuff from the introductory text to the paper:

Carbon dioxide (CO2) capture and storage (CCS) has been discussed as a potentially key tool in the stringent mitigation required to restrict climate warming to within 2 C relative to preindustrial levels.(1,2) CCS represents the capture of CO2 mainly from large point sources and its injection into subsurface reservoirs, usually at 8002000 m below the seafloor.(1,3−5) In Europe, CO2 storage capacity is chiefly located offshore within sandstone aquifers.(6,7) Currently, this storage capacity lies principally within Norwegian waters, where the multinational energy company Equinor (formerly Statoil ASA) operates the Sleipner CCS facility that has injected ∼1 Mt y1 of CO2 into the Utsira formation since 1996.(8,9) Procedures guide the selection of appropriate subseabed CO2 storage sites,(5,10−12) which have been suggested to present lower risks for human populations in case of accidental leakage compared to terrestrial locations.(13,14) However, there is a need to identify suitable procedures for the monitoring of active and closed marine storage sites to ensure their adequate operation and enable identification and quantification of potential leaks.(15)

Diverse potential scenarios of subsea CO2 leaks have been simulated.(16−20) This includes large CO2 releases resulting from a massive failure of a facility (e.g., a blowout).(19) The high daily release of 10,000 t d1 of CO2 from a point source in the North Sea for a full year was predicted to reduce pH by 0.25 units up to 141 km away from the source, and by >2 units nearer to the source. The magnitude of such releases makes it unlikely that they could remain undetected or ignored for prolonged periods. On the contrary, smaller gas leaks remain largely ignored, such as the release of 570 t d1 of methane at the 22/4b blowout crater in the UK North Sea, more than 20 years after the 1990 accidental blowout,(21,22) or the widespread natural gas seepage resulting from offshore oil and gas activities.(23,24)

In the absence of strong bubble plumes, the high solubility of CO2 leads to its rapid aqueous dissolution from bubbles within a few meters of their emission into the sea as indicated by field and laboratory data, and model simulations.(13,16,20,25−27) Consequently, small CO2 leaks disperse in ambient seawater over short distances(20,28) and are therefore particularly challenging to detect without careful monitoring techniques.(20) For example, a recent study indicated that the detectability of a relatively low leakage rate of gaseous CO2 of 85 kg d1 would be limited to < 30 m horizontal distance from the release source and ≤ 2 m from the seafloor.(20) Nevertheless, such small single-source releases of CO2 were evaluated as largely insignificant in terms of storage performance, and a single leak of this magnitude would therefore not prevent CCS sites from retaining a millennium climate mitigation effect.(20) However, migration pathways within geological formations and overlying sediments may lead to numerous, spatially distributed emission sources under some circumstances.(14,29) There is concern that several small-sized leaks may remain undetected under these conditions. Being able to ensure leak detection and flow rate determination is particularly important for monitoring of storage sites because major leaks may offset the benefits of energy-intensive CCS facilities.(1,30−32)

At present, two alternative, complementary strategies exist to investigate the impact of potential subsea CO2 leaks: experimental releases and natural CO2 seeps. Manmade subsea (bed) experimental releases of CO2 require costly logistics and afford limited distribution of emission source(s).(15,20,33,34) Natural CO2 seepages(13,17,29,35−38) exhibit less-constrained flow rates and may present more spatially distributed emission sources. The seep system offshore Panarea Island (Aeolian Islands, South Italy) is one of the most easily accessible natural seeps(25,29,36,39−42) and was selected for this study as a realistic leakage analogue.

Here, we use field data collected in May 2014 at a natural CO2 seep site covering ∼18,000 m2 offshore Panarea during cruise POS469 of the R/V Poseidon(29,43) to provide insights about the possible geochemical impacts of CO2 leaks from subseabed storage reservoirs. A new simulation tool is developed and validated with field data. This model builds on the existing multiphase bubble and droplet plume model Texas A&M oil spill (outfall) calculator (TAMOC).(44−50) Here, we couple this model to a Lagrangian advection-dispersion model that tracks the movement of dissolved CO2 in the water column and to a model of CO2 speciation in natural seawater (the csys software(51)). Simulations provide a means to evaluate the mass flow rate at CO2 seepage/leakage sites based on observed anomalies in seawater chemistry (e.g., pH or partial pressure of CO2, pCO2). The model is intended to be used as a tool for analyzing field data and to guide sampling during experimental CO2 release experiments and field monitoring of existing and future storage sites.


The authors some details about their study site...

Panarea is the smallest of the seven major islands of the Aeolian volcanic arc situated offshore northern Sicily and western Calabria (Figure 1).(29,52) The ongoing volcanic activity started ∼1.5 Ma ago in this region.(52,53) The offshore CO2 gas seep system at Panarea has been known since historical times.(52) These emanations originate from an underground geothermal reservoir fed by a magmatic body.(36) In this near-shore setting, thermal waters and >90% pure CO2 gas are emitted into the sea at depths ranging from < 10 m to > 300 m below the sea surface...


...and then there's lots of discussion of their modeling tools.

I only have time to post some pictures and captions from the text:



The caption:

Figure 1. (a) Position of the two study sites (station PCTD3 and Bottaro crater) offshore Panarea, and (b) position of Panarea Island offshore Italy in the South-East Tyrrhenian Sea. The position of the ADCP instrument is also indicated. (c) A zoom on station PCTD3 indicates the 130 venting sites identified by video recording. The diameter of the circles is proportional to the number of identified bubble streams per site (up to 10 per site, 294 in total). High-resolution bathymetry offshore Panarea(112) was plotted with ArcGIS 10.2.




The caption:

Figure 2. (a) Observed initial bubble size distribution at Bottaro crater on May 12, 2014 (solid dots) and bootstrap 95% confidence interval (gray area). (d50 = volume median diameter). (b) Evolving average composition of the gas phase from the emission source at a 12 m depth (vent C) to the sea surface, as predicted by TAMOC for all simulated compounds (solid lines = measured initial bubble size distribution, shaded area = 95% confidence interval as defined on panel a, displayed only for CO2), and measured in the field for CO2 (). (c) Fraction of the CO2 released at the emission source remaining within gas bubbles as a function of depth, according to the TAMOC simulation.





The caption:

Figure 3. (ac) Simulated pH map at three time points on May 8, 2014 and (d) observed map of pH calculated for May 8, 2014 at 8:4511:15 am, at 12 m above the seafloor (panels ad). (d) The map was generated from measured data (+ symbols) using ordinary kriging as implemented in the EasyKrig Matlab software (version 3.0, Dezhang Chu and Woods Hole Oceanographic Institution, downloaded from ftp://globec.whoi.edu/pub/software/kriging/easy_krig/V3.0.2-Matlab2016b/ on Jan 28, 2019); based on the variogram, the following parameters were used. Model: general exponential-Bessel, nugget: 0, sill: 1, length: 0.15, power: 2, hole scl: 0, range: 0.95. The reader is referred to Movie S-1 for model predictions at a 10 s time step interval. The spatial extent covered by panel (d) is indicated on panels (ac) by a black rectangle.




The caption:

Figure 4. Average pH over a 24 h period (May 89, 2014, from 8 am to 8 am), at (a) 01 m and (b) 12 m above the seafloor. The solid black line indicates the potential impact limit (ΔpH = 0.15


These waste dumps, the authors conclude, from their modeling exercise are quite prone to leak, where, like all the crap piled up in the quixotic and failed so called "renewable energy" scheme that didn't work, isn't working and won't work, they will be the charge of the same future generations whose resources we are actively squandering on wishful thinking and consumerism.

Nevertheless such dumps will not have as dramatic effect as the 35 billion tons now being dumped every year with no place to put it even while people with no scientific or engineering education prattle on about 75,000 tons of solid used nuclear fuel.

We will kill the entire ocean because, um, um, um, we think that Chernobyl wiped out central Asia and Fukushima wiped out Japan.

Sigh...

The authors conclusions, the bold being mine:

Simulated predictions at station PCTD3 are taken as an indication of potential local CO2 impacts assuming the leaks occur in an undisturbed, pristine environment. Here, changes in pH are assumed to dominate the potential impacts on the local ecosystem in the vicinity of a leak from a storage facility, neglecting the role of CO2 itself in observed toxicity.(1) Previous studies(19,20,105) have argued that environmental impacts are unlikely when the acidification remains below the range of natural variation of pH over the year (assumed <0.15 pH units based on data for the North Sea(20)). Drops in pH (ΔpH) from 0.20.5 pH units have been termed potentially harmful, with ΔpH ≥ 1 pH units identified as significantly harmful.(20) Observations at Panarea Island have reported quantitative and qualitative differences in ecosystem structures at seep sites relative to unaffected sites (ΔpH of 0.10.6), including a 4.5-fold increase in microphytobenthos productivity and a 5-fold decrease in faunal biomass linked with decreased diversity.(89,106) Future ocean acidification resulting from the rising CO2 atmospheric concentrations may drastically alter the carbonate cycle in world oceans (possibly decreased precipitation of carbonate minerals), potentially leading to major environmental community shifts involving calcifying organisms.(107−110)

On a 24 h average basis, an area of 3900 m2 experiences a ΔpH of ≥ 0.2 pH units (Figure 4), calculated for the 01 m bottom water layer, with a rapid decrease of the impacted area at shallower depths (1200 m2 at 12 m above seafloor). On an instantaneous basis, ΔpH can reach up to 2.2 pH units locally, with a maximum area of 6300 m2 experiencing significantly harmful pH drops (ΔpH ≥ 1). During the 24 h period shown in the figure, an average area of 600 m2 (standard deviation: 1300 m2) experienced ΔpH ≥ 1 at any given time. The pH varied over short time scales as a function of time-varying water currents (Movie S-1), and this result may depend on the period within a 28-day tidal cycle. It is likely that marine organisms can survive acute exposure to ΔpH values of this magnitude,(1) and we hypothesized that the 24 h average ΔpH is likely representative of the chronic exposure level.

These local estimates must also be considered in the context of ongoing anthropogenic CO2 emissions: the pH of world oceans is predicted to decrease by up to 0.4 pH units by the end of the 21st century relative to the preindustrial level.(3,111) As a consequence, the local impacts faced by marine communities near such leakages (≤ 1.9 102 km2 experiencing ΔpH ≥ 0.5) would be dwarfed by a change of similar magnitude in the surface waters of world oceans (361 106 km2).(71)


Have a nice weekend.

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