Seismic monitoring of Lake Nyos, Cameroon

摘要: On 21 August 1986 a cloud of dense gas was emitted from Lake Nyos in Cameroon causing death, by asphixiation, 1700 people the nearby villages. An international relief effort initiated and scientific teams number countries were sent to order determine cause release. It agreed that carbon dioxide, which predominant cloud, had deep-seated magmatic origin lake charged with it prior outburst. Uncertainty remained, however, about mechanism its eruption lake; particular, whether overturned response small external trigger or phreatic volcanic occurred. In an attempt resolve this problem following report second ‘eruptive event’ on 30 December 1986, British Geological Survey installed network hydrophones geophones around during February 1987. During six months, regional earthquakes local events, interpreted as rockfalls, detected but no significant crustal found beneath close lake. No clear evidence magma movement other signs activity found, suggesting direct not involved. The lack tectonic seismicity at monitoring period argues against earthquake for wider province, many such cannot be completely ruled out.