The first thing to do then is to locate a nearby nasty volcano that would impact the Ethiopian highlands while not necessarily been noticed elsewhere. As it turns out one of the top ten and the only one in Africa is located in the Republic of Congo directly west of Ethiopia. The ash cloud would certainly envelope those same highlands as they are naturally down wind.
At the same time it is noticed that an Alaskan volcano also reduced Nile water levels as well in 1912.
All this argues strongly for proper dating and size estimation of all major volcanos and their correlation with ice core work and climate studies..
7. Mount Nyiragongo – DR Congo
Nyiragongo volcano is one of the most active volcanoes in Africa. It is noted for long active lava lakes which appear in the summit crater. Nyiragongo is one of eight volcanoes in the Virunga Mountains. The volcano is located near the town of Goma in the eastern Democratic Republic of Congo. It is a stratovolcano located inside Virunga National Park. Apparently, nowhere else on the globe does such a steep-sided stratovolcano contain a lake of such fluid lava like Nyiragongo. Nyiragongo’s lava lake has at times been the most voluminous known lava lake in recent history.
Since 1882, it has erupted at least 34 times, including many periods where activity was continuous for years at a time. The last devastating eruption of Nyiragongo occurred on 17th January 17, 2002, when lava flows down the flank of Nyiragongo covered approximately 40% of the town of Goma, rendering at least 120,000 people homeless, displacing most of Goma’s population of 500,000. This volcano is currently active, with Nyiragongo in an eruption that has been ongoing since May 2002. Nyiragongo’s lava lake remains active to this day.
Since January 2009, recurrent seismic swarms have been detected at Rusayo seismic station. The volcanic earthquakes have come mainly from Nyiragongo volcano, which contains an active lava lake. According to a report by scientists from the volcano observatory in Goma the same signs that preceded the 1977 and 2002 eruptions have been identified. Possibly this means another eruption in near future.