Mexico’s Volcano-Watchers Closely Monitor Popo’s Vital Signs
The eruptions have ended--for now. But though the volcano Popocatepetl has settled down into an ashy sulk after a series of Christmas season explosions, there’s no rest for the scientists at Mexico’s National Center for Disaster Prevention.
They are still at their posts, watching the 17,887-foot monster’s every move, as members of their team have been doing every day, 24 hours a day, for more than five years from the center’s headquarters here.
Aided by remote cameras and sensors, five scientists trade off this duty. They work on four-day rotating shifts and monitor every sigh and hiccup emanating from “Popo,” which is about 40 miles southeast of this capital.
Their chief is Roberto Quaas Weppen, director-general of the 10-year-old disaster prevention center. His life has become so entwined with the volcano that he speaks in almost affectionate terms of its “personality” and sometimes refers to it as “my volcano.”
The 53-year-old mechanical engineer has been quite literally in touch with the mountain for years: A computer is programmed to call him automatically on a cell phone if Popocatepetl so much as twitches.
For Quaas and his team, along with scientists at the nearby campus of the National Autonomous University of Mexico, or UNAM, who advise them, Popocatepetl’s eruption last month was their triumphant debut after years of quiet toil. The team’s forecasts of danger were by and large correct, and no lives were lost when the volcano began spewing fire.
Mexico, with limited resources for research, has not often been seen as a scientific beacon. But in this kind of practical science, the nation stands proud. Quaas’ efforts to make the center a model for handling disasters have won praise from scientific observers.
Developed countries may have superior resources, said Bob Tilling, a volcanologist with the U.S. Geological Survey, but they tend to focus on more abstract research. By contrast, he said, countries such as Mexico “do good, solid applied research--they are not thinking about Nobel Prizes and that sort of thing.”
Quaas and his team, working with the USGS, have made Popocatepetl one of the most watched volcanoes in the Western Hemisphere. They have wired it from top to bottom, using such an extensive network of cameras and sensors that Quaas compares the mountain to a hospital patient, its vital signs pulsing continually across computer screens.
“We can’t give it medicine to cure it,” Quaas can’t resist saying. “But we can do preventive medicine.”
Therein lies one of the more difficult problems in science. Volcanologists know just enough to anticipate eruptions before they happen but not enough to be precise. If they recommend evacuations too frequently when no eruptions occur, people may disregard warnings--with deadly consequences.
“It’s not clear whether it is responsible to say that something will erupt--it’s like if someone drops a cigarette in a theater and yells, ‘Fire!’ Well, there isn’t a fire, but there may be one,” said Jon Davidson, a petrologist and volcano specialist with the University of Durham in England.
The complications are heightened in Mexico because the volcano lies in purview of three states and the federal government, and quite a few people living near Popo have been disinclined to heed warnings.
“There is a saying that goes, ‘Exact science is hard science,’ ” Quaas said. “But the science isn’t hard. Working with society is much more difficult.”
Quaas learned this the hard way. When the center was formed in response to the Mexico City earthquake of 1985, he and most of the researchers were thinking of quakes rather than volcanoes. “No one was interested in Popo then,” he said. “It was just a national symbol.”
When the volcano showed signs of awakening in the early 1990s, it was by chance that its rumblings were detected: An earthquake seismograph at UNAM happened to pick up a strange, volcanic palpitation.
In 1994, Quaas had just begun work on a monitoring system for the mountain when Popo jolted awake during the Christmas break, emitting a cloud of ash.
Quaas learned of the eruption from television news. Shortly after, he and the few scientists who had rushed to the center found themselves facing a grim government minister. “The minister said, ‘Are we going to evacuate, yes or no?’ ” Quaas recalled. “Imagine. We didn’t know anything.”
Quaas’ team recommended the evacuation of 20,000 people, but the eruption did not prove severe. They never wanted to repeat that experience. With the help of the USGS, efforts to monitor Popo resumed. Plans were laid, systems designed, equipment installed. Scientists zoomed up the mountain’s slopes on motorcycles and flew over the crater.
Today the mountain is decked with video and infrared cameras, 15 solar-powered seismic stations that constantly transmit data, a Doppler radar to track nighttime emissions of ash and tiltmeters to detect the slightest heaving of the mountain’s sides. The information is beamed to a second-floor laboratory, where it is digested by volcano watchers.
The first test came at 6:19 a.m. Dec. 2. The seismographs began rattling, and alarms went off. The team was thrilled: Its gadgets were performing exactly as hoped, recording the first hiccup of the mountain’s awakening. Popo was again emitting a cloud of ash.
It was the same weekend that the government of new President Vicente Fox was assuming power. The scientists were thrust into the spotlight.
Over the ensuing days, they tracked more blips and burps. Then, nearly two weeks later, the volcano released a cloud of gas and the seismographs began recording something extraordinary: a series of harmonic tremors that created such fine lines that they looked like gray mist on the graph paper. “It was continuously breaking the needles on our machines,” Quaas said.
Authorities evacuated 40,000 nearby residents. A few days later, when it was possible to fly over the crater, scientists saw what they had feared: A lava dome that Quaas said was the size of four soccer stadiums had formed in the crater.
But the mountain’s next trick was unexpected: It grew quiet. The evacuees were waiting to return home. Pressure was mounting; had the volcano watchers given a false alarm? They didn’t think so. To make their case, they took an unusual step: They forecast that the mountain would erupt within a matter of days; they even went so far as to pinpoint a time, Quaas said.
Quaas said this forecast was never made public, and UNAM volcanologist Jose Luis Macias noted that it remains controversial among some scientists. They generally avoid making such specific predictions, said the USGS’ Tilling. But Quaas and others believed that they needed a strong argument for why people should not be allowed to return to their homes.
Popo began erupting right on schedule.
The team had shown its worth to the new government. When, in days that followed, the mountain again grew quiet--this time with Christmas approaching and nerves wearing thin--the scientists were emboldened to make another forecast: This time they said there would be an eruption within three days.
They missed.
The repercussions, Quaas said, were swift and ugly. “There was a lot of pressure,” he said. “People said to us, ‘You failed.’ Some officials tried to discredit us. . . . I was very nervous and upset.”
Fortunately for him, there was no time for complaints. A day later, Popo finally obliged the scientists, its emissions becoming a fountain of fire by Dec. 26. Their timing had been off, but they were not wrong.
Quaas praises all parties for their response during the days of eruptions that followed. But the disaster center was at the heart of the effort. Fifteen minutes after the explosion, new Interior Minister Santiago Creel showed up at the lab, his young son in tow, to watch the readings come in. The center’s Web site received more than 200,000 hits in one day.
Macias, the UNAM scientist, cautions that the center’s efforts, while efficient, have not been perfect and warns against the perils of overconfidence. The social and political complexities of ordering evacuations remain huge, he said. And Popo remains active, still capable of surprises.
