The lava lake in the crater of Nyiragongo volcano in the Democratic Republic of the Congo has existed since at least 1928, pictured here in March 2010.
Image: AP
Warning signs exist for most volcanic eruptions, but not all. A dramatic exception occurred in Africa in 2021
Eearthquakes cannot be predicted. On the other hand, researchers in a related field of geosciences are far more successful. In many cases, they can warn of volcanic eruptions quite accurately. The fact that earthquakes play a decisive role in this may sound ironic at first, but magma movements below a volcano almost always lead to stresses in the earth’s crust, which are discharged in earthquakes. However, the predictability of volcanic eruptions is not a universal law of nature. Again and again there are cases in which mountains of fire eject lava without giving a single measurable sign.
An international research group has now investigated an extremely dramatic case of a sudden, unexpected eruption of the Nyiragongo volcano in East Africa. The almost 3500 meter high Nyiragongo in the east of Congo is fed together with its sister volcano Nyamuragira by the magmas of the Albertinian Rift, the western extension of the East African rift system. Along this large rift in the Earth’s crust, the African continent separates from the Indo-Australian lithospheric plate, and Africa breaks apart. Nyiragongo is a wonderfully cone-shaped stratovolcano less than 20 kilometers north of the Congolese city of Goma. It is one of the most active volcanoes on earth, its crater is constantly filled with a lava lake.