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Danger?

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We are staying just next to lake Kivu right on its banks. Just wanted to know what are the chances of the lake overturning in the near future.

I'm not an expert but from my studies, probably low compared to Lake Nyos or Lake Maroun however there seems to be evidence of routine overturns in Lake Kivu's past (last 5,000 years). I would read this link to get a better feeling: http://www.eawag.ch/research_e/apec/Scripts/Lorke_publication_lake_kivu_2002.pdf
I would caution that any lavaflows or volcanic activity around the lake could be more dangerous than if compared to a 'normal' lake. This being said, volcanic activity is dangerous even without lake overturn so maybe you and your family should prepare a family disaster plan and emergency supply kit. You could try moving to a different area or higher ground, but that doesn't mean you are safe from different type of disasters like flood, earthquakes or other events. I would enjoy the beautiful lake and leave these types of things to God or Allah or whatever. You may also try to organize lake vents like the one in Lake Nyos through community action, local political organizations and international NGO's.
The danger of a lake turnover is ever-present on Kivu, and may be categorised as a moderate but increasing risk. Turnover risk is not constant, but the next one requires either the passage of time (up to 100 years at current rates of accumulation of gas to reach saturation), or a major energetic event such as an in-lake volcanic outburst (several have happened leaving cones on the lake bed), or perhaps a major inflow of lava from an existing live volcano such as Nyiragongo to trigger it. There is a continuous accumulation of carbon dioxide and methane in deep water, with gas accumulation increasing at about 0.5% annually (see EAWAG Schmid et al. reports). This rate of gas accumulation would raise the gas saturation at several levels in the lake to close to 100% by 2100, if such accumulation is not pre-empted by extraction or an earlier turnover. At 100% saturation, at any depth in the lake, gas can spontaneously bubble out of the water, the champagne effect, initiating a likely self-sustaining spout of gas and water ascending to the surface. As such a spout gathers energy, the spout widens to hundreds of metres, perhaps kilometres, drawing in the gas-saturated water from wider and deeper in the gas-saturated zones deep in the lake. In the space of about one day, as much as 360 billion cubic metres of gas could be released (2010 basis), with a greenhouse gas equivalent of 3 billion tons of carbon. This would be a major disaster event, potentially worse that the 2006 Boxing Day tsunami.
While modelling of the actual turnover is currently too simplistic and inaccurate to predict the ferocity of the event and the time to completion, it can be confidently predicted that the following will occur: (1) A gas and water spout erupting from the surface can surge 10-25m above the lake surface causing waves and violent currents that may be of tsunami dimensions and also causing a surge in lake level of up to a couple of metres as the spout widens to maximum. (2) A surge in lake level combined with tsunami-like waves can inundate low lying lake-side villages and causing a surge in lake outflow down the Ruzizi river valley, eventually threatenining Bujumbura on the shores of Lake Tanganyika. (3) Clouds of gas given off at the spout may be clear or opaque (steam-like) and will spread across the lake surface rapidly. Density of the gas cloud, with is an 80% carbon dioxide and 20% methane mix, is probably slightly denser than air (1.33 vs 1.29) so will lie on the lakes surface if calm (but could disperse with a strong wind). The gas cloud may reach a depth of about 300m which can engulf towns and cities such as Goma, Bukavu, Kalehe, Gisenyi, Cyangugu, Kibuye etc. Any person or animal in this cloud would be asphyxiated within minutes. Wind may disperse the gas cloud and reduce casualties. (4) The lake waters will be severely disturbed, with fast flowing currents away from the water/gas spout and inward-flowing deep water dredging up silt and sludge ffrom the lake bottom. Once the surge has retreated the lake depth may have dropped a metre or more and the water will be smelly, brown and virtualy anoxic. The best safety measure is to climb to high-ground well above 300m or to remain in a well-sealed house/room for as long as the cloud takes to disperse. Considering that the lake has not turned over in possible one thousand years, and assuming that the methane can and will be extracted, the risk of a turn-over is about the same as the risk of a new volcano forming in the lake bed but the effects will gradually diminish as the methane content is drawn down over time. George Nowak (talk) 13:04, 1 April 2010 (UTC)[reply]
Add to article, fantastically interesting. 89.217.21.27 (talk) 18:27, 21 March 2015 (UTC)[reply]

The "See also:" links on this page--violation of policy.

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I am concerned that the link to Retreat at Lake Kivu violates Wikipedia policy. It seems to me that the correct location for information about the stand for peace against genocide that this link represents belongs at a Wikinfo page.

The policy that this link violates is Wikipedia is not a soapbox.

I am new to editing wikis, so I will not remove this link immediately. But as I grow used to participating in this community, it is likely that I will remove the link, and seek the removal of its sister page.

Mkitabu 12:31, 8 April 2006 (UTC)[reply]

Sorry, I don't see how the Retreat at Lake Kivu article is soapboxing. Seems like a fairly neutral article but I don't know the forum and what it's about. Perhaps there is some controversy of which I'm unaware. The association between a Lake Kivu article (as a geologic feature) and international forum is a strectch, however may have some limited historical merit. Anyway, I don't care one way or the other about keeping the link in this article, however deleting the Retreat at Lake Kivu article doesn't seem reasonable at all. Revmachine21 13:11, 8 April 2006 (UTC)[reply]

WP:LAKES

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I've added this lake to the WP:LAKES project. Please help to standardize and improve lake-related articles, and feel free to join the project! Em3rald 17:05, 17 June 2006 (UTC)[reply]

size

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This article calls Idjwi the tenth largest inland island while the article on Idjwi claims it is the eighth largest.—Preceding unsigned comment added by 60.231.182.212 (talk • contribs)

I think you've stated the reverse of the situation, but you've edited it the right way. The line at Idjwi is sourced so it takes precedence. - BanyanTree 10:23, 21 August 2007 (UTC)[reply]

Methane is abiogenic

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The methane of this lake is really abiogenic in origin.Agre22 (talk) 23:38, 29 May 2009 (UTC)agre22[reply]

As the article stands, there's no comment on the methane's origin, though as a geologist I'd agree that you're probably right on it being essentially abiogenic. A recent Nature article (http://www.nature.com.libezproxy.open.ac.uk/news/2009/090715/pdf/460321a.pdf, Nature vol460 p321 "A lakeful of trouble" ; no I haven't worked out the syntax of the reference tag yet) implies that some of the methane is from reduction of the volcanic CO2. The test for this would be to examine the isotopic composition of the CO2 and the associated methane ; whether that as been done is not clear, but the article's figures repeat the assertion that the methane is the result of biological reduction of the volcanogenic CO2.
I'll correct the article, pending someone coming up with more detail.
Aidan Karley (talk) 20:43, 22 August 2009 (UTC)[reply]


The methane's origin has been debated with two pathways considered as having the largest potential and contribution. (1) The biogenic route where dead algae, fish, plankton and plant material accumulate on the sediment layer at lake bottom and are anaerobically digested. Through the acetate pathway there is about a 50:50 production of methane and carbon dioxide. The alternate route through Archaea methanogens has been debated where the oxygen in carbon dioxide is stripped out and replaced with hydrogen to create methane is a very interesting and attractive option as it would contribute hugely to a sustainable energy cycle on our planet. There is definitely a contribution of carbon dioxide of volcanogenic origin, but the carbon isotopes signature could then find its way directly into methane via only the second route above. George Nowak (talk) 13:16, 1 April 2010 (UTC)[reply]


@Agre22, A Karley, and George Nowak: Has anyone actually checked to see whether the methane comes from the CO
2 or not? (Carbon-14 radioactivity would be a simple way.) I find it hard to believe that it does. In order to convert CO
2 into methane there would have to be a source of something like hydrogen or hydrogen sulfide. But I haven't heard that there's hydrogen sulfide (which would be converted to sulfur or sulfuric acid). I would guess that the methane is produced from biomass (George's first alternative), and this would produce carbon dioxide rather than consuming it. Eric Kvaalen (talk) 08:54, 10 July 2019 (UTC)[reply]
@Eric Kvaalen, Agre22, and George Nowak: I don't know if anyone has actually considered the question important enough to invest effort into answering. Dealing with the threats of overturning release of the CO
2 probably has priority on the budget.
C-14 in any measurable proportion would tell you that the origin of the carbon has a less than ca.10kyr transit time from the atmosphere. But the absence of detectable C-14 would not tell you if the origin of the carbon was from essentially primordial (origin of the Earth, or the Moon-forming impact) or from 100kyr dead fish.
The C-13:C-12 ratio might suggest how many times the carbon has been through a biological cycle, or possibly which cycles the carbon has been through (photosynthesis has a slightly different effect on these "stable isotope ratios" to methanogenisis, for example). But the interpretation is difficult and at best suggestive rather than diagnostic.
H
2S detection is relatively easy (electrochemical cells, IR spectrophotometry, I've installed and used both ; GC or GCMS would also work) and a very important thing to measure and monitor whenever you're dealing with reduced organics in water. Every time - every damned time - that I present a H
2S safety course at work, whichever nationality I'm presenting to, and in whichever language, I have always been able to find a recent case of a multiple-fatality H
2S incident, in the home country of the people I'm training. Normally I manage to find a multiple-fatality within one family. Most often it's farmers, but the year before I entered the job market it was three distillery workers just 20 miles from my home. Not performing proper monitoring of H
2S levels in the produced water would be criminally culpable.
I've done several jobs in Tanzania since last contributing to that article (which has acquired some inconsistencies since), and am still looking for work in the area, including the Rift valleys. I'm trying to learn Swahili, at least to a level better than ordering a beer. AKarley (talk) 11:12, 17 July 2019 (UTC)[reply]


Thanks and good luck. I've also heard of a lot of cases of people being killed by going into a pit or something which has a lot of carbon dioxide. Eric Kvaalen (talk) 12:39, 17 July 2019 (UTC)[reply]
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