Lakes are de-gassed to avoid mass deaths

Two African lakes that killed 1,800 people in the 1980s may again release deadly amounts of CO2, University of Michigan-Ann Arbor scientists report.

George Kling and colleagues say current preventive efforts are insufficient to prevent another disaster at Lakes Nyos and Monoun in Cameroon.

Since the deadly release of carbon dioxide clouds each lake has been outfitted with a pipe to vent CO2 into the atmosphere.

The researchers explained the CO2 is entering the lakes from magma under the Earth's surface.

The team's 12 years of data indicate both lakes have CO2 saturation values of 80 percent to 90 percent -- indicating each lake's pipe is not enough to dissipate all the gas.

The scientists determined that during the next 10 years, each pipe will only remove approximately 30 percent of the gas, thereby reducing, but not eliminating, the risk of a cloud release.

By modeling past and future CO2 refill rates, the researchers suggest adding an additional pipe to Lake Monoun and four more to Lake Nyos to prevent another disaster.

The research appears in the early online edition of the Proceedings of the National Academy of Sciences.

Copyright 2005 by United Press International