Goma after the 2002 Eruption of Nyiragongo
The activity at Redoubt has captivated a lot of us, but in the grand scheme of things, its eruption are more likely to caused inconvenience and property damage rather than dramatically loss of life (unless something huge and unexpected occurs). However, the same cannot be said if Nyiragongo and/or Nyamuragira (a.k.a. Nyamulagira) in the Congo were to erupt. These volcanoes are close to the city of Goma, a city of nearly 600,000, not including refugees from the fighting in the region. Eruptions of Nyiragongo in 2002 prompted the displacement of 400,000 people as lava flows invaded the city.
Currently, Dieudonne Wafula, lead scientist at the Volcanological Observatory of Goma is reporting that there is increased seismic unrest underneath the volcanoes - mostly centered under Nyamuragira, however activity is seen at both volcanoes. Luckily, right now at least, the lava lake at Nyiragongo is low, which might reduce the damage if an eruption were to take place. The Red Cross is standing-by in case an eruption occurs or evacuations are needed.
Both volcanoes have lava lakes at the summit, and these lava lakes have the potential to drain rapidly, sending fast-moving lava flows into populated area. It is, in fact, one of the few places were lava flows present such a large volcano hazard for people (lava flows are a large problem for property many places as it can't get out of the way). In 1977, the lava lake at Nyiragongo drained catastrophically, sending the basaltic lava down the side of the volcano at nearly 100 km/hr (60 mph), killing 70 people.
Nyiragongo is somewhat unique in the sense that the lava erupted from the volcano is very low in silica, thus very fluid, so when the lava lake breached, this very fluid lava rushed down the volcano at speeds much faster than most lava flows (which you could out-walk). This fluidity was probably amplified by the fact that the lava was all stored in a lava lake, keeping a large volume hot and ready to move. Something like this is not likely to happen at other basaltic volcanoes such as those in Hawai'i. In recent volcano research news, Dr. Asish Basu at Rochester University thinks that this unique nature of the Nyiragongo lavas - their isotopic composition especially - is due to the fact that a new "plume" is reaching the Earth's surface in this part of Africa. It is an interesting theory, but not one that has been robustly analyzed yet. In any case, the activity at Nyiragongo and Nyamuragira are well worth our attention as any major eruption could have dire consequences for the people living in Goma and the eastern parts of the Congo.
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One measure of the threat posed by Nyiragongo is that it is one of the sixteen Decade Volcanoes named by IAVCEI. For those not familiar with the decade volcanoes, they were designated as such to promote study of volcanoes deemed particularly dangerous due to their eruptive history and proximity to population centers.
Good point, Ed. Maybe when I get a chance, I'll write something up on the Decade Volcanoes, or at least a summary of the volcanoes and their significance.
Interesting how the activity at Nyamuragira might affect the activity at Nyiragongo.
I do wish to point out however that Nyiragongo erupts nephelinite with an abundance of minerals from the melilite group. I searched and searched to find a %SiO2 for the lavas but I found nothing, only that they are "mafic" and "less silica-saturated than alkali basalt. I understand that nephelinite is found in abundance in the Great Rift Valley and that it has recently started to mix with the carbonatitic magma of Ol Doinyo Lengai, producing a more viscous and explosive lava that is currently building a cone that now covers all of those bizarre hornitos that existed in its active crater. I'm eagerly awaiting the next chapter in the story of that volcano too.
One more thing - I know that Nyiragongo hosts an active lava lake, but I have not heard the same of Nyamuragira; in fact, having seen recent satellite photos of the volcano published online, there's not even any significant degassing from Nyamuragira. At any rate, it is a shield volcano and Nyiragongo has a stratovolcanic profile (despite its current lava fluidity) indicating that at some point an explosive magma erupted and built a stratovolcano there, but not at Nyamuragira.
I almost feel guilty talking about the crazy geological happenings in the Great Rift Valley, as if the ongoing war is a mere triviality. People have evacuated from places where death at human hands was all but certain to Goma, which has two volcanoes that maybe pose a lesser risk than staying where they were, but a risk nonetheless. Out of the fire and into the frying pan? Hopefully now that Rwandan troops have supposedly dealt with the Hutus in the area and *captured!* the main rebel leader who engaged in vigilantism (and war crimes, depending on who you believe) against those who supposedly were complicit in the Rwandan genocide back in the 1990s, will allow that ongoing war a breath of peace, but...
In a democratic country where people did not lead hand-to-mouth lives, day by day, getting by with what survival skills and resources they had, making use of things we would toss away as garbage, to make it to tomorrow, where fear for your life and the lives of your family was not something you had to deal with regularly...in Canada (my home) for example, a serious natural disaster, say a flood (a typical Canadian disaster), would make people draw closer as a community, sandbagging, donating funds to help build dykes and volunteering to help people who were forced to evacuate their now-destroyed property. And there would be insurance money or government support or both to rebuild and get back to life as usual, without fear. There might be a death toll, but it would be very low.
But if one or both of those volcanoes has a serious eruption, it will add just one more level of chaos to an already chaotic region, and I cannot imagine the consequences. Can volcanoes trigger genocide?
Sorry to go on and on, but putting money into studying how volcanoes work, identifying other precursors to eruptions, etc. has never been more important. With global population expanding, people are forced to live in places prone to natural disasters, there is nowhere else. The last thing this active war zone needs is a volcanic eruption.
Chris - Thanks for the comment! I went back and checked about the lava lake at Nyamuragira and I could be wrong. The statement from the SI/GVP is:
A lava lake in the summit crater, active since at least 1921, drained in 1938, at the time of a major flank eruption. Now, whether that means that the lava lake is there right now, I'm not sure. You have to love these silica-undersaturated volcanoes ... always erupting oddball magmas.
As for the political ramifications of an eruption, that is anyone's guess. I tried to think of a direct example, but I'm coming up blank so far. Any readers got any good examples of political/social upheaval directly related to an eruption?
Could someone tell me if it is possible to follow online the evolution of seismic activity in the Great Lakes region and a good website with some reliable data on volcanic activity in the region? I am planning a visit in the very near future, and I would like to have some more background before I leave.
Kind regards, G.
Thanks for the info. Keep it up Chris.
Interesting how the activity at Nyamuragira might be affecting the activity of its neigbour though they are close in proximity. We are following the outcomes and learn together just incase it breaks the seal abruptly. Thumb up Chris.
I'm pretty certain that the lava lake at Nyamlagira disappeared at the time of the 1938 Tshambene flank eruption and has only made brief reappearances since; Haroun Tazieff would not have invested so much effort over so many years in reaching the Nyiragongo lake if one had existed for sustained periods in the more easily accessible caldera of its neighbour
Any readers got any good examples of political/social upheaval directly related to an eruption?
Mount Pelée in Martinique erupted in 1902. The eruption killed about 30,000 people. Most deaths occurred in Saint-Pierre, a city in Martinique, due to pyroclastic flows. There was an election coming up. The island governor needed the votes of the city residents. So the gov discouraged people from fleeing, even though, in hindsight, there were signs of an impending eruption. It has been a while since I read the story. I can't remember the title or author, but it included a lot of quotes from people on ships, who of course lived to tell the tale.
Vesuvius erupted causing not only the loss of Pompei but the detruction of a complex system of waterways which fed the most valuable agricultural regions of the Roman Empire. What followed was famine and then plague and then the fall of the Roman Empire. Santorini erupted and brought to an end the Minoan civilisation and much of civilised society around the whole Mediteranean. The more worrisome thing is the number of volcanoes which today find themselves surrounded by massive populations, would modern Italy survive a major eruption of Vesuvius, given that 11 million people now live under it? Would modern America survive a reawakened Yellowstone? There are a great many places where a single volcano now has the potential to devastate a country's economy. Volcanoes have this amazing ability to both start and end life.
Do volcanoes produce cheese?
I like sausages
Deftly tight and up on chicken flicks