GOMA, Democratic Republic of Congo — Deep inside the volcano’s crater, a cauldron of scarlet lava spits, bubbles, and boils. Clouds of foul-smelling gas billow up and over the rocky rim.
On a recent morning, park ranger Jean-Bosco Simpeze peered into the angry pit, then turned to face the plain below. The dawn light caught a reminder of previous eruptions — a black carpet of lava, snaking from the mountain base toward Goma, a lakeside city 10 miles away.
The recent, massive gas emissions were not normal, Simpeze noted. “The volcano must be angry again,” he said.
Mount Nyiragongo, inside Congo’s eastern border with Rwanda, erupted almost two years ago. Fountains of lava burst from its flanks and streamed into Goma, the provincial capital of 500,000 inhabitants.
The fiery river cut through the town as if through butter. Neighborhoods burned. Businesses were flooded. Lava crawled across the airport runway and gutted the main cathedral. Remarkably, only about 100 people died.
International scientists now warn that the feisty volcano could blow again at any time. And the next eruption may be much worse.
“It will be a catastrophe — no possibility of escape,” said Jacques Durieux, a French volcanologist with the Goma Volcano Observatory.
The center of eruption has moved since the January 2002 event, he said, shifting south toward Goma along a series of underground fissures. So when the volcano blows, the lava could gush from under the city’s rutted streets, giving residents practically no time to flee.
“We know it will erupt again; we know how and we know where,” Durieux, standing on a mound of lava rock inside the town, said recently. “The only thing we don’t know is when.”
Another, even greater disaster is possible, he added. If the eruption occurs under Lake Kivu, the magma could trigger the release of vast quantities of gas now trapped underwater. A lethal cloud of methane and carbon dioxide would rise, smothering as many as 4.5 million people on the lakeshore in Congo and Rwanda, Durieux said.
Such a calamity is considered a minor possibility in Goma, although it has happened elsewhere. In 1986, a lethal gas emission from Lake Nyos in Cameroon claimed 1,800 lives.
Nonetheless, Durieux said, “I prefer not to think about it.”
Often shrouded in clouds, Nyiragongo is a mystery to specialists as well as locals. One of two active volcanoes along the Virunga Mountains, Nyiragongo has lava flows as fast as 25 miles per hour and its center of eruption is volatile.
In January 2002, members of the Kiza family were watching the distant lava flows from their home on the edge of Goma, when suddenly the ground split open at their feet.
“I was sitting on the crest,” said Furaha Kiza, 13, pointing to the site where her family once lived. “Then the ground started shaking and fire came out.”
Her father, Evarist, who was too sick to run, was swallowed by the lava.
In a future eruption, her family may have more warning. A series of digital seismographs recently installed around the volcano provide a continuous stream of data to the observatory in Goma. Physical and chemical warning signs should allow volcanologists to predict the next eruption about three weeks in advance, Durieux said.
For now, there are more-immediate worries. Satellite images collected by NASA show Nyiragongo is emitting more than 59,000 tons of sulphur dioxide every day, according to Dario Tedesco, a professor of environmental science at the University of Naples currently working at the Goma observatory.
The poisonous plume has withered nearby forests and fields, he said, but also contains large quantities of fluorine, which has seeped into local water supplies. As a result, fluoride levels are more than 10 times the recommended maximum in some villages. Villagers are showing signs of dental fluorosis, a rotting of the teeth caused by the excess.
The effects were clear in Sake, a bustling marketplace about 20 minutes west of Goma. Almost every villager, randomly observed, had brown-stained teeth; many were rotting. Serugendo Dubrae, 40, moaned about his sore molars. “Maybe it’s the water,” he said with a shrug. “I don’t know.”
Despite the threat, Goma continues to grow. At current rates, the city’s population will reach 1 million by 2015. Apart from the villagers perishing in the lava, aid workers worry of a potential cholera epidemic after any future eruption.
But the most obvious step — moving the city entirely — is nearly impossible, Durieux said.
“Never in the history of man has a city evacuated before a natural catastrophe,” he said. “People always come back and rebuild the cities in exactly the same place.”
In Congo, still reeling from five years of civil war, the idea of a dramatic relocation is even more fanciful. Mount Nyiragongo is just one of many hazards, ranging from rapacious gunmen to AIDS, that stalk Goma’s weary inhabitants. Still, some cling to the idea of moving.
Alphonse Kassole, a butcher whose business was destroyed in the last eruption, is leading a campaign to have Goma moved 30 miles along the lakeshore. He has formed a lobby group, the Association for the Relocation of Goma.
“This town has no future. When you build a house here, you can’t be sure your son will be able to live in it,” he said. “But for now, we have nothing better.”