Survivor of Lake Nyos disaster recalls his experience

staff_reporter Member Photo

Clipped by staff_reporter

Survivor of Lake Nyos disaster recalls his experience - Africa facing risk of more gas disasters ROBIN...
Africa facing risk of more gas disasters ROBIN McKIE Science Correspondent A YEAR AGO, Sule Umare, a young Cameroon cattle herder, survived a cataclysm that wiped out most of his family and tribe as they lay in their huts. ' We thought that rain was coming, ' he recalled. ' I went out and saw the moon shining. I wondered about how rain could come without clouds : I started exclaiming " Allah Akbar" and then I fell.' Sule was a victim of a tidal wave of carbon dioxide and water particles that swept over his village from nearby Lake Nyos on the evening of 21 August, 1986. The toxic wave contained about 85 million cubic feet of gas and 200,000 gallons of water, and poured into valleys, killing 1,700 people. Only a handful, including Sule, survived West Africa's worst natural calamity. Now, exactly 12 months later, British scientists who investigated the catastrophe revealed that it could have been prevented. They have also warned that other lakes in Cameroon and nearby Nigeria could also erupt with similar death tolls. Seeps up They say the only solution is to build special pipelines and pumps that will stop carbon dioxide building up in the lakes. However, no efforts are being made at present to implement such measures even though they would protect hundreds of thousands of people now at risk from carbon dioxide poisoning. The British team presented its report to the Foreign Office earlier this year. Contrary to speculation at the time, it concluded that the disaster, in the remote highlands of equatorial Cameroon, was not caused by a volcanic eruption of poison gas. 'The problem comes from carbon dioxide that seeps up through the Earth's crust in this part of the world,' said one investigator, geologist Dr Sam Freeth, of University College, Swansea. ' The gas gets dissolved in lakes. In very deep ones, such as Nyos, a great deal of carbon dioxide is forced into solution by the huge pressures at the bottom of the lake.' When this solution nears saturation it becomes unstable, the scientists say. ' Only a slight disturbance in lake conditions would trigger a catastrophic release of gas at this pressure,' Dr Freeth said. ' For instance, a strong wind over the surface could have been sufficient, ' although we may never find the exact trigger of the Nyos disaster.' The overturn of this deep layer of carbon dioxide solution caused the gas to be released as it rose to the surface and the pressure dropped. 'At the surface, the release of gas. transformed the accompanying water into a fine mist and sent a wave of water crashing across the lake,' the report says. ' The water and carbon dioxide swept down the valleys to the north of the lake through Nyos and on to Subum, Cha and Fang, leaving a terrible toll of injury and death in its wake. ' Air contains small amounts of carbon dioxide but at the high concentration found in the Nyos tidal wave it was toxic. The fumes killed victims in villages and market towns over a huge area within a minute, while those who survived often suffered gas burns. Others were injured as they fell. At the time, the disaster was considered to be unprecedented. Yet there had been several warnings. In particular, an identical carbon dioxide eruption occurred at Lake Monoun in Cameroon in 1984 but was not properly investigated because the death toll 37 people was considered low. ' Had a full-scale study been done, we might then have realised the extent of this problem,' said Dr Freeth. 'In fact, there are about 60 or so lakes in Cameroon and Nigeria, any of which might be at risk. Some are too shallow to allow carbon dioxide to build up, but several must be deep enough. Certainly, it is very unlikely that there are not at least half a dozen lakes in this region that do not pose a serious threat to life.' These dangers can be resolved, maintain the scientists. The construction of pumping stations would permit the removal of gas-saturated water layers from the bottom of affected lakes. ' The British Government could do more but there is also a need for some greater international effort to solve this very worrying problem.' IlipiiiKlp A child victim of Cameroon poison mist 1

Clipped from
  1. The Observer,
  2. 16 Aug 1987, Sun,
  3. Page 6

staff_reporter Member Photo
  • Survivor of Lake Nyos disaster recalls his experience

    staff_reporter – 23 May 2018

Want to comment on this Clipping? Sign up for a free account, or sign in