National Geographic : 2011 Apr
• Nyiragongo has an intricate plumbing system, widespread as the roots of a tree, and once the initial seam opened, the pressure blew open vents systemwide, shooting out fountains of molten rock, including in the very center of town. e risk, it turns out, is not just near the city of Goma, but directly beneath it. e lava had steamrolled through forests and neighborhoods. It looked as if a ten-lane high- way had been dropped down the mountain's flanks, right across the city. Though the next eruption will likely follow a similar path, thou- sands of homes, shacks of hand-hewn eucalyptus boards and sheet-metal roofs, have been built directly atop the old ow. Real estate brokers sell tiny lots consisting of nothing but lava rocks enclosed by lava walls for as much as $1,500. And if Goma doesn't have enough to worry about, the thousand-square-mile Lake Kivu conceals an enormous underwater concentration of carbon dioxide and methane. e theory is that a major eruption could release it, spreading a lethal cloud across the city that would spare no one. A er a full day of hiking, Sims and Tedesco reached the barren, wind-wracked summit rim. A long line of porters hauled camping gear, climbing equipment, scienti c instruments, food, and water. From here, the scientists looked into the mouth of the volcano. Crumbly sheer walls ringed by ledges dropped a quarter mile down to a vast, at oor, black with hardened lava. In the middle, contained in a giant soup-bowl-shaped spatter cone, was a stunning sight: a lake of lava. The lake was 700 feet across---one of the largest in the world---with a mesmerizing ka- leidoscopic surface. Black plates were cut by jagged cracks of orange, violently shi ing and roiling. One moment the crust took the form of a shattered windshield, then it coalesced into a jigsaw puzzle, then a ragged map of the world. e lake roared like a jet plane taking o and emitted a thick white plume of dozens of deadly gases. " e whole periodic table is churning in there," Sims said. Even from the rim the scientists could feel the heat. e 1800°F lava exploded from the lake in electric orange geysers, several every min- ute---25 feet high, 50 feet, 100 feet, bursting into evanescent arches of liquid rock morphing from orange to black in midair as they cooled. e lake seemed to breathe, expanding and contract- ing, rising and falling, its surface level changing several feet in a matter of minutes, spectacular and terrifying at once. Sims was awestruck. " ere," he said a er a long silence, pointing down at the lake, "is where I'd really love to get a sample." SIMS IS 50 YEARS OLD, an avid rock climber and former professional mountain guide. He doesn't like cities; he's allergic to crowds. He dresses as if life were one long camping trip. A professor at the University of Wyoming, he lives in Laramie with his wife and two young children. He hasn't owned a TV set in 25 years. Volcano science has never been a safe occupation---more than 20 scientists have died on volcanoes in the past 30 years. Sims carries a scar on his right arm from Sicily's Mount Etna, where his shirt melted into his skin. He's even-tempered and analytical and seemingly never o duty. He once wrote a pa- per on a restaurant tablecloth, scribbling until 3 a.m. en he took the tablecloth home. Tedesco, 51, is ery and fashion conscious, an inexperienced alpinist and an unrepentant epicure. On the Nyiragongo expedition, where every ounce hauled up the mountain was care- fully considered, Tedesco brought a large glass bottle of extra virgin olive oil. He lives with his wife, teenage daughter, ve cats, and three dogs just outside Rome and is a professor at the Sec- ond University of Naples. When he speaks of Nyiragongo, he drops all pretense of scholarly dispassion. "It's no secret that I love Goma," he says. "My greatest fear is to make a big mistake--- not to predict an eruption." Sims led the descent into the crater, anchoring ropes and spidering down walls. e rest of the party followed. Nyiragongo is in the Great Ri Valley, where the African continental plate is be- ing wrenched apart, and microquakes constantly n Society Grant This expedition was funded in part by your National Geographic Society membership.