THE city of Goma and the surrounding area of eastern Congo hold many dangers, including armed rebellions, famine and volcanic explosions.
But there is another, more mysterious threat: large reservoirs of methane and carbon dioxide lying deep beneath Lake Kivu's surface and shores. While the methane can be tapped for energy, the gases can also kill.
Dieudonne Masha and a neighbour w
ere walking home along the shores of Lake Kivu after a round of drinking.
As the neighbour tells it, the two were confronted by a pair of soldiers patrolling the area, who asked to see their identity cards. Masha did not have his.
"He decided to make a run for it," said the neighbour, Innocent Rwagatore.
Masha fled to a nearby rocky ditch. When his body was found the next morning, in the place where he had apparently been crouching for hours, there were no signs of violence.
Masha is believed to have died instantly when he hid in an invisible bubble of carbon dioxide, known as a mazuku, or "evil wind" in Swahili.
A freshwater lake split between often warring Congo and Rwanda, Lake Kivu is a hub of commerce that sits in a seismically active region, with lava occasionally flowing into it from nearby volcanoes. The eruption of Mount Nyiragongo near the lake's northern shore in 2002 stimulated new interest in the gas fields beneath its surface: 392 billion cubic yards of CO2 and 78 billion cubic yards of methane slowly building to a saturation point, or potential release. It could take centuries, scientists say, but some experts argue that another eruption of Nyiragongo or nearby Mount Nyamulagira — Africa's most active volcano — could set off a devastating gas release.
Similar events have been recorded at least twice before, on lakes in Cameroon during the mid-1980s. In one case, more than 1,700 people were killed. But Kivu is many hundreds of times bigger, and scientists say the amount of gases trapped underwater is larger.
The lake's rare chemistry has also presented a financial opportunity. The World Bank has earmarked more than $3 million ( for gas extraction that could harvest years of energy for the countries of the African Great Lakes region, and it has been promoted by Rwanda and Congo as a centrepiece of the new and shaky peace between the former enemies. According to Rwanda's minister of energy, nearly 60 companies have come forward expressing interest.
The likelihood of a major gas release remains unknown. Some of the scientists studying the lake have been hired as consultants for big-money deals. But war and a lack of resources also make the lake and volcanoes difficult to monitor closely.
"The problems of the lake are not just chemical, they are political," said Dr Dario Tedesco, a volcano expert who is writing the United Nations' contingency plans for Nyiragongo's next eruption.
Still, the mazukus are a chilling and constant reminder of the power within the earth. According to Dr Tedesco, nearly 100 people like Masha die each year from the CO2 vents along Lake Kivu's northern shore. Stories of people feeling breathless and lightheaded when swimming in the lake are common, which could contribute to the many drownings there. In the aftermath of the Rwandan genocide in 1994, many died from mazukus that sent clouds of gas into jam-packed refugee camps along the lake.
"We've known for a long time," said James Nzumuka, Goma's district mayor. Signs displaying skulls and warning of the mazuku danger are spread around the area, and children have been told to stay away from the lake. Every dry season Goma's children die, not from thirst, but from drowning. From June to August, when the rains stop, so does the regular water supply to many of the city's residents. In a summertime ritual, children go to the lake to fetch buckets of water. Many can't swim.
Such was the case for Marie Bazimuka's son Abu Bakar, 11, who disappeared in July while fetching water from the lake with a friend. His body was found two days later.
"During the dry season, the lake likes to kill people," said Bazimuka. "It's a kind of demon, a devil."
For Goma, which has struggled to form a semblance of a functioning government, keeping track of the deaths is difficult. A calamity division of Goma's police force, which was established last year, reported nine bodies were found in the lake last August; the mayor's office recorded 14. Neither has a record of Abu Bakar's death in July. According to Bazimuka, who said three other children died the same day, most deaths are not reported.
