Living in the Shadow of Vesuvius

V OLCANOLOGY magma will fail and the volcano will erupt On the other hand, the Rabaul caldera is a complicated phenomenon, researchers when exponentially accelerating seismicity looked to have a good head of steam up when say, so prediction will likely remain compli- ECTION or deformation approaches infinite propor- it reawakened in late 1983, says Robert Till- cated even as observations and analyses con- S tions. Applied in hindsight, this method ing of USGS Menlo Park. “You would have tinue to improve. Thus, although volcanolo- would have predicted a number of eruptions made a very precise forecast,” he says, “but it gists can take pride in successful predictions at Mount St. Helens, Redoubt, Izu Shima in would have been wrong.” The populace was that have saved tens of thousands of lives in Japan, Montserrat, and Galeras, Voight says. put on high alert in October 1984, but things recent decades, they cannot become compla- PECIAL Others have also found exponential ac- promptly quieted down. It did not erupt until cent: The science and the technology, while S celeration to be a useful predictor. In the 1994. And in 1997 an intrusion beneath Long impressive, have been tested on only a few September 2002 issue of the Journal of Vol- Valley drove an alarming crescendo of seis- volcanoes during short parts of their lives. canology and Geothermal Research, John micity without reaching the surface. “There are so many unknowns,” says Dan Murray of The Open University in Milton Despite some encouraging developments Miller. “We can’t see the magma chambers Keynes, U.K., and Juan-José Ramirez Ruiz with LP events and runaway activity, many or the plumbing system leading up into the of the Colima Volcano Observatory in Mex- volcanologists remain cautious on predic- volcano.” And characteristics crucial to the ico report that swelling of Colima’s upper tion. “There’s no magic bullet here that will successful ascent of magma such as gas con- cone began accelerating almost a year before allow us to monitor volcanoes,” says Tilling. tent, viscosity, and mechanical resistance to its 20 November 1998 eruption. Applying “Even if monitoring data is good, it can’t [al- ascent vary from volcano to volcano and Voight’s method, successful predictions of ways] distinguish between a large explosive even from one intrusion to the next. It makes the eruption’s timing could have been made event and a magma intrusion without an weather forecasting look like a snap. as early as 25 weeks ahead, they say. eruption.” The rise of magma into a volcano –RICHARD A. KERR NEWS Living in the Shadow of Vesuvius Researchers at the oldest volcanological institute probe the inferno beneath people alive. their feet and wrestle with the politics of civil protection The good news for modern-day Naples is that, so far, there is no sign of such a NAPLES,ITALY—From the snow-capped meters per hour toward the 600,000 people head of steam building under the vol- heights of Mount Vesuvius, the city looks living around the base. These pyroclastic cano—but just to be sure, it is being like a densely woven blanket wrapped flows can blast through stone walls up to 3 watched around the clock by the Vesuvius snugly around the volcano’s slopes. From meters thick and can flash-fry living matter. Observatory. Just shy of 158 years old, the up here, with sunlight glinting off the Beyond this annihilation zone, ash and vol- observatory was the first volcanological broad crescent of the bay and far from the canic rock fragments called tephra shower station ever built. Its recent directors have din of traffic, Naples and its surrounding down over a wide area, quickly accumulat- turned it into an international center of re- towns look peaceful. This tranquillity ing enough material—up to 500 kilograms search and a testing ground for urban vol- makes it all the more difficult to imagine per square meter—to collapse roofs, burying canic risk management. Techniques and the worst-case scenario models developed by ob- that volcanologists be- servatory scientists, often lieve Vesuvius could with international collab- inflict on Neapolitans: oration, are now used a repeat performance across the globe. But not of the A.D. 79 eruption surprisingly, says Grant that famously destroy- Heiken, a volcanologist at ed the Roman towns Los Alamos National of Pompeii and Her- Laboratory in New Mexi- culaneum. co, having responsibility In this scenario, for the most heavily pop- Vesuvius does not ooze ulated volcano in the lava and throw up a few world adds real-world rocks as Hawaiian vol- pressures to the science. canoes do. The pressure Over the past few years, from below just builds while helping the govern- and builds until it goes ment draw up an evacua- off like a bomb, sending tion plan for the area, ob- a superheated column servatory scientists be- of rock, ash, and gases came involved in a bitter 20 kilometers into the dispute, which split the sky. Within hours, this Italian volcanology com- roiling mixture of gas munity, over how much and dust collapses back warning Vesuvius would and roars down the Ring of fire. The urban sprawl of Naples is surrounded by the active volcanoes Vesuvius, give of a major eruption. slopes at up to 240 kilo- Ischia, and the Campi Flegrei. The academic mudslinging CREDIT: GIUSEPPE VILARDO/VESUVIUS OBSERVATORY 2020 28 MARCH 2003 VOL 299 SCIENCE www.sciencemag.org V OLCANOLOGY S PECIAL has subsided, but observatory scientists are tional research collaborations. Apart from the straight geophysics, the continuing to cajole colleagues in Italy and Some long-standing partnerships are al- Neapolitan area supports a better “mar- elsewhere to help them protect the millions of ready bearing fruit. Gasparini and his col- riage” of archaeology and volcanology than people living in Vesuvius’s shadow. leagues are putting the finishing touches on perhaps anywhere else, says observatory S a decade-long Vesuvius project called volcanologist Sandro de Vita. Orsi agrees: ECTION A volcanologist’s paradise … TOMOVES that has produced the clearest Last year, he authored a provocative paper Down in the city, volcanologist Giovanni picture yet of the “deep plumbing” of a vol- arguing that the global impact of the Campi Orsi chain-smokes behind mountains of pa- cano (Science, 26 November 1999, p. 1685). Flegrei eruption 39,000 years ago sparked per on his desk at the observatory. “Vesu- By using a technique called seismic tomog- the transition from Neandertal dominance to vius may be the most famous volcano, but raphy—setting off small explosions and ana- modern Homo sapiens. De Vita and his col- it isn’t the greatest threat to Naples,” says lyzing the waves as they bounce back off dif- league Mauro Di Vito are also studying the Orsi. “People are more aware of it because ferent layers of rock—they are able to locate more recent history of the area, concentrat- it looks like a classic volcano. But the the limestone “floor” beneath Vesuvius, as ing on the coevolution of the volcanoes with Campi Flegrei are far more dangerous,” he well as the location of magma. the cultures of their human inhabitants. Ev- adds, referring to the western side of the The same method is also being used to idence of human activities going back 6000 bay that is pockmarked with years remains frozen in time craters. This was the exit point between layers of mud and of the largest eruption in ash from the frequent erup- Mediterranean history, 39,000 tions. In spite of these period- years ago, which launched at ic catastrophes, the rich mud least 200 km3 of magma—the flats produced by the erup- equivalent of 200,000 solid- tions keep luring large groups stone Empire State Buildings. of farming people back to the That blast caused the area to very same place. collapse into the broad dish- shaped caldera that now cups … And a volcanologist’s the western part of Naples and purgatory the town of Pozzuoli. Just west of Naples, en- The 1 million people at risk sconced within the dense from a Campi Flegrei eruption town of Pozzuoli, lies an enor- would be far more difficult to mous yellow-white crater evacuate. Add to that the vol- called the Solfatara. Enrica canic island of Ischia just off Marotta wrinkles her nose. the western arm of the bay, “Yeah, it always stinks,” she home to 50,000 and host to says. The rotten-egg smell of thousands of tourists in sum- sulfurous gases billowing mer, and it becomes clear that Retired, but not forgotten. After 155 years of vigilance on the volcano’s slopes, from cracks is generated by an Naples has the potential to pro- the original Vesuvius Observatory is now a museum. aquifer interacting with mag- duce a disaster on an epic scale. matic gases several kilometers But for the time being, that possibility seems map the underlying structure of the Campi beneath the surface. Marotta, an observatory remote, and from a researcher’s point of view, Flegrei in a project called SERAPIS. Re- volcanologist, points out two glass bulbs says Orsi, the area has long been “a paradise searchers have now gathered the data, says connected to tubes emerging from the for volcanology.” According to Paolo Gas- project leader Aldo Zollo, a geophysicist at ground. These containers are used to meas- parini, who was director of the observatory the University of Naples, and are beginning ure the amount of carbon dioxide escaping from 1971 to 1983, the first seismometer was to analyze them. But some results are al- from below.

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