Nyiragongo poses many potential hazards other than lava flows, such as Mazukus (“evil winds” in Swahili), which are low-lying locations with dry CO2 vents, volcanic ash, phreatomagmatic eruptions from the high water table, earthquakes, and the possibility of the degassing of Lake Kivu (Lockwood, 1994).
An Evolving Rift System
If the rift system continues to evolve underneath Lake Kivu and nearby Nyiragongo volcano, there is the possibility that lava may again break out in the city of Goma, or worse yet, underneath Lake Kivu (Reed, 2002). Possible fissures associated with rifting would be more hazardous than any prior volcanic eruption if they cause rollover within the lake. It is important to realize that although Lake Kivu has not overturned recently, the chance of occurrence still exits. It is when even well studied volcanoes depart from their “expected” behavior that hazards take place (Martinelli, 1991). Perfect examples are the catastrophic eruption of Mt. St. Helens in Washington which consisted of a lateral blast never before displayed by the volcano, the eruption of Mt. Unzen in Japan which killed volcanologists Maurice and Katja Krafft as well as many journalists in which a slightly larger than average pyroclastic flow was observed, and the previously described eruption of CO2 gas from Lake Nyos before which a large scale release of gas from a volcanic lake had never been seen.