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The 1986 Lake Nyos gas disaster in Cameroon, West Africa
OLR (1987) 34 (9)
F. General
87:5286 Sorer, Steven (comment) and L.A. Frank (et al., reply), 1987. [Discussion ofl 'On the influx of small comets into the Earth's upper atmosphere.' Geophys. Res. Letts, 14(2):162-167. The Frank et al. hypothesis that 'holes' in terrestrial ultraviolet dayglow emission are caused by water vapor originating in the breakup of numerous small icy comets is refuted on the grounds that such comets would have been detected optically. Frank et al. disagree: 'Sorer overestimates the detection rates of the proposed small comets with the M.I.T. space surveillance telescope by factors of around 102-103.' (fcs)
F380. Advances in science, reviews (general interest) 87:5287 Brasseur, Guy, 1987. The endangered ozone layer. Environment, 29(1):6-11, 39-45. This in-depth examination of global ozone depletion covers seasonal, latitudinal, and historical trends in stratospheric ozone; measurement methods, ozone chemistry, interactions with other trace gases, predicted long- and short-term variations (various models), and details the unfolding story of the seasonal Antarctic ozone minimum. Several variations of chemical theories (destruction by chlorine, chlorine and bromine oxides, or nitrogen oxides) and dynamical theories (temperature decrease, reduced planetary-scale wave activity, diabatic circulation) are presented, but none are viewed as clearly superior. New data suggest that the ozone hole is more complex than originally believed and may require a combination of chemical and dynamical approaches to explain its origin. Free Univ., Brussels, Belgium. (gsb)
87:5288 Donovan, S.K., 1987. [Report.] Iridium anomalous no longer? Nature, Lond., 326(6111):331-332. The considerable body of data which links an anomalously high concentration of iridium at the Cretaceous-Tertiary boundary with a bolide impact has led to searches for similar evidence of other major geological boundaries where mass extinctions are recognized. Among the sections examined to date, concentrations of iridium have been found at two Ordovician-Silurian localities where the iridium is probably of terrestrial origin and at a PermianTriassic and a Frasnian-Famennian (Upper Devonian) locality, which appear to represent regional
793
depositional variations. Dept. of Geol., Univ. of the West Indies, Mona, Kingston 7, Jamaica. (hbf)
87:5289 Heyning, J.E. and J.L. Chovan, 1987. Wanted dead or alive. The Natural History Museum's Marine Mammal Stranding Program. TERRA, 25(3):1523. The procedures for recovery and examination of live or moribund marine mammals, primarily cetaceans, in the Los Angeles and Orange counties region are described. An example is given of a blue whale that was struck by a container ship. (gsb)
87:5290 Kerr, R.A., 1987. Tracking the wandering poles of ancient Earth. Science, 236(4798): 147-148. New analyses of polar wandering, actually the movements of the Earth about a spin axis fixed with respect to the stars, indicate that the North Pole has moved about l0 m toward eastern Canada since 1900, 5 ° of wander have occurred over the past 90 m.y., and a 10 to 150 shift occurred between 70 and 100 Mya, a rate at least half that of continental drift. Although the cause of these changing rates is not known, it seems inevitable that these motions are associated with a redistribution of mass on or within the Earth. (hbf)
87:5291 Kling, G.W. et al., 1987. The 1986 Lake Nyos gas disaster in Cameroon, West Africa. Science, 236(4798): 169-175. The sudden, catastrophic release of gas from Lake Nyos on 21 August 1986 caused the deaths of at least 1700 people in the northwest area of Cameroon, West Africa. Chemical, isotopic, geologic, and medical evidence support the hypotheses that (I) the bulk of gas released was carbon dioxide that had been stored in the lake's hypolimnion, (2) the victims exposed to the gas cloud died of carbon dioxide asphyxiation, (3) the carbon dioxide was derived from magmatic sources, and (4) there was no significant, direct volcanic activity involved. The limnological nature of the gas release suggests that hazardous lakes may be identified and monitored and that the danger of future incidents can be reduced. ®1987 by AAAS. Dept. of Zool., Duke Univ., Durham, NC 27706, USA.
87:5292 McMenamin, M.A.S., 1987. The emergence of animals. Scient. Am., 256(4):94-102. The Precambrian world consisted of a single, huge continent with retreating glaciers and low levels of
F. General
87:5286 Sorer, Steven (comment) and L.A. Frank (et al., reply), 1987. [Discussion ofl 'On the influx of small comets into the Earth's upper atmosphere.' Geophys. Res. Letts, 14(2):162-167. The Frank et al. hypothesis that 'holes' in terrestrial ultraviolet dayglow emission are caused by water vapor originating in the breakup of numerous small icy comets is refuted on the grounds that such comets would have been detected optically. Frank et al. disagree: 'Sorer overestimates the detection rates of the proposed small comets with the M.I.T. space surveillance telescope by factors of around 102-103.' (fcs)
F380. Advances in science, reviews (general interest) 87:5287 Brasseur, Guy, 1987. The endangered ozone layer. Environment, 29(1):6-11, 39-45. This in-depth examination of global ozone depletion covers seasonal, latitudinal, and historical trends in stratospheric ozone; measurement methods, ozone chemistry, interactions with other trace gases, predicted long- and short-term variations (various models), and details the unfolding story of the seasonal Antarctic ozone minimum. Several variations of chemical theories (destruction by chlorine, chlorine and bromine oxides, or nitrogen oxides) and dynamical theories (temperature decrease, reduced planetary-scale wave activity, diabatic circulation) are presented, but none are viewed as clearly superior. New data suggest that the ozone hole is more complex than originally believed and may require a combination of chemical and dynamical approaches to explain its origin. Free Univ., Brussels, Belgium. (gsb)
87:5288 Donovan, S.K., 1987. [Report.] Iridium anomalous no longer? Nature, Lond., 326(6111):331-332. The considerable body of data which links an anomalously high concentration of iridium at the Cretaceous-Tertiary boundary with a bolide impact has led to searches for similar evidence of other major geological boundaries where mass extinctions are recognized. Among the sections examined to date, concentrations of iridium have been found at two Ordovician-Silurian localities where the iridium is probably of terrestrial origin and at a PermianTriassic and a Frasnian-Famennian (Upper Devonian) locality, which appear to represent regional
793
depositional variations. Dept. of Geol., Univ. of the West Indies, Mona, Kingston 7, Jamaica. (hbf)
87:5289 Heyning, J.E. and J.L. Chovan, 1987. Wanted dead or alive. The Natural History Museum's Marine Mammal Stranding Program. TERRA, 25(3):1523. The procedures for recovery and examination of live or moribund marine mammals, primarily cetaceans, in the Los Angeles and Orange counties region are described. An example is given of a blue whale that was struck by a container ship. (gsb)
87:5290 Kerr, R.A., 1987. Tracking the wandering poles of ancient Earth. Science, 236(4798): 147-148. New analyses of polar wandering, actually the movements of the Earth about a spin axis fixed with respect to the stars, indicate that the North Pole has moved about l0 m toward eastern Canada since 1900, 5 ° of wander have occurred over the past 90 m.y., and a 10 to 150 shift occurred between 70 and 100 Mya, a rate at least half that of continental drift. Although the cause of these changing rates is not known, it seems inevitable that these motions are associated with a redistribution of mass on or within the Earth. (hbf)
87:5291 Kling, G.W. et al., 1987. The 1986 Lake Nyos gas disaster in Cameroon, West Africa. Science, 236(4798): 169-175. The sudden, catastrophic release of gas from Lake Nyos on 21 August 1986 caused the deaths of at least 1700 people in the northwest area of Cameroon, West Africa. Chemical, isotopic, geologic, and medical evidence support the hypotheses that (I) the bulk of gas released was carbon dioxide that had been stored in the lake's hypolimnion, (2) the victims exposed to the gas cloud died of carbon dioxide asphyxiation, (3) the carbon dioxide was derived from magmatic sources, and (4) there was no significant, direct volcanic activity involved. The limnological nature of the gas release suggests that hazardous lakes may be identified and monitored and that the danger of future incidents can be reduced. ®1987 by AAAS. Dept. of Zool., Duke Univ., Durham, NC 27706, USA.
87:5292 McMenamin, M.A.S., 1987. The emergence of animals. Scient. Am., 256(4):94-102. The Precambrian world consisted of a single, huge continent with retreating glaciers and low levels of