Sadly, the death toll from the recent eruption rose to at least 20, after 5 people were found choked to death from toxic fumes when they attempted to cross one of the recent and barely cooled down lava flows that had cut through their neighborhood in an area 13 km north of Goma.
What gas exactly caused their death was not mentioned, but one speculation is it could odorless carbon dioxide trapped in depressions on the surface of the flow – the slopes of Nyiragongo are infamous for many fissures and ground vents emanating accumulating sometimes deadly concentrations of the highly toxic gas.
Nature of eruption still unclear
While the eruption is probably over or at least in a pause, it’s still not clear whether the lava erupted was from a sideways fissure connected with the central conduit that drained the lava lake from the volcano’s summit caldera, or from a new lateral conduit tapping a separate reservoir.
During an overflight, the scientists from the Goma Volcano Observatory were not able to see whether the lava lake in the summit caldera was still present or not due to thick cloud cover.
What seems to worry local people almost as much as a potential re-activation of the eruption and new lava flows are frequent earthquakes that have started to occur under the flanks of the volcano since the eruption.
It is hoped that these reflect internal re-adjustments after the dike and the connected reservoir that had caused the eruption had been emptied. A more concerning prospect would be if the tremors are being caused by magma movements underground, something that cannot be ruled out.
„If there is lava in the crater, the fracturing caused by the movement of the earth would represent new activity.“
„If there is no lava in the crater, then these earthquakes are happening because the earth is in the process of refinding its balance.“, the director of the volcano observatory, Kasereka Mahinda said.
According to the Rwanda Seismic Monitor, the quakes had magnitudes of up to 5 and most of their epicenters were located in Cyanzarwe and Rubavu sectors (SE of the volcano). The strongest so far was a 5.1 event under Lake Kivu in the Rubavu district at 08:37 GMT. A 4.5-magnitude quake followed at 11:53 GMT. According to information via AFP, many people are afraid to stay indoors due to the quakes.
It appears that schools and most other public buildings remain closed, and electricity is still down in much of Goma
Link: Volcano death toll rises as aftershocks shake DR Congo (phys.org)