Changes in population distribution as a response to volcanic activity in the Western Highlands of Cameroon
by
Sam J Freeth
Geological Hazards Research Unit, University of Wales, Swansea, SA2 8PP, U.K.

In August 1986 a cloud of toxic gas, released from Lake Nyos in the Western Highlands of Cameroon, swept down the valleys to the north leaving more than 1700 dead and dying people in its wake. In the immediate aftermath of the disaster it was obvious that the lake water was still highly charged with gas and within a year or so of the disaster it became apparent that the amount of gas in the lake was recovering at an alarming rate. Recent studies confirm that the amount of gas in the lake is now at, or near, its pre-disaster level and that the lake is now as dangerous as it was prior to the 1986 disaster, however, in 1986-87 such studies were in the future and were dependant on monitoring changes which would only occur with the passage of time. For those working in the area there was a pressing need to decide whether or not the lake was likely to release another toxic cloud in the immediate future and the only way to answer this question was to look at the previous history of the lake. But history, in that part of Cameroon, in the sense of a continuous record of official government reports etc, only goes back to about 1950, and in the sense of intermittent travellers reports, by a further 50 years or so! So any attempt to look into the more remote past would depend partly in an interpretation of oral history and partly on other factors, such as changes in population distribution. Presumably, if a gas disaster, similar to that which occurred in 1986, had occurred fifty or a hundred years previously then the population would have abandoned the area only to return as the memory faded. In case of Lake Nyos it would appear that the valleys to the north had been abandoned at some time in the past and that from 1948 (the date from which we have the first hard evidence) through to 1986 the area was in a recovery phase with people moving in - but people from outside the immediate area rather than local people for whom any residual memory of a previous disaster would have been most potent.

Date received: August 19, 2002