Was pondering this again today; it is so unusual for scientists to speak out in public like this. They have to, though, because of all the risks I mentioned in earlier posts as well as the local civil strife, conflicting economic interests, etc., that make everyone want to look away (Douglas Adams called it an SEP field: Somebody Else's Problem).
But another thought came to me just now. If Lake Kivu did explode, and if it did release all of the CO2 and methane estimated to be down there, could it have global environmental effects in addition to causing a local disaster of literally biblical proportions and severely tightening the global flow of
coltan?
It's
estimated that Lake Nyos released about 0.6 cu km of carbon dioxide when it
exploded in the 1980s., displacing all air for about 16 miles around it, killing almost everyone and every animal.
Per that paper linked earlier in the thread, Lake Kivu contains about 300 cu km of carbon dioxide (not a typo) AND about 60 cu km of methane, which Rwanda is carefully mining to fill some 10% of its power needs right now (have to find that source again but it's a credible one).
I think the Nyos tragedy caught experts by surprise; they've learned a lot about such lakes since then, but there are so many unknowns about what such a disaster at huge Lake Kivu would be like.
Anybody have any thoughts on what climate effects might occur from the sudden release of that much gas -- 300 cu km of CO2 and 60 cu km of methane -- in the general neighborhood of 1.5° S, 29.25° E?
I have no idea how high the column might get. That involves complicated physics and related science, of course, but certainly there would be a need to add heat to take it up high enough to spread out in either hemisphere.
While methane is explosive, would the CO2 prevent ignition?
A submarine landslide could set the lake off, they say (triggered perhaps by a powerful earthquake); let's assume the worst: eruption through fissures in the lake floor. There
are fissures down there (extensions of the ones that erupted in May and that also run through Goma) and there
is magma down there, though it's not moving any more and hopefully is solidifying in place.
But in trying to look at the possible global effects, let's assume the lake floor does erupt. That will add gases of its own as well as heat (with resulting buoyancy increase). The methane layer will be affected first because it's denser than CO2. That's a respectable smothering blanket of carbon dioxide, but with the extra gases injected steadily, increased buoyancy, magma-water interactions, and so forth...
Well.
I'm thinking that the lake eruption column would get very high, possibly up into the stratosphere, and perhaps carrying some sulfur compounds from the fresh magma, but then would quickly subside back down to "normal" altitudes (
Surtseyan type in a lake floor volcanic eruption ).
Not that anyone would be around then to see it.
Just trying to be objective, what effects in terms of local and/or global weather and climate could the sudden but limited addition of that much gas have?
Of course, the millions of people. I'm blocking that out just now, but that is the reason why it's true what that volcanologist tweeted above: no more business as usual. This awful but very real problem must be addressed. Now.
They've been working on it since at least the 1990s. It's too complicated to be solved, but there really needs to be an independent, top-notch, well-funded local observatory monitoring the situation constantly.
