SCIENTISTS
SAY IT IS INEVITABLE THAT THE MIGHTY VOLCANO WILL ERUPT ANEW.
BUT PREDICTING WHEN IT WILL HAPPEN AND FIGURING OUT HOW TO EVACUATE
HUNDREDS OF THOUSANDS OF PEOPLE LIVING ON ITS SLOPES ARE VEXING
CHALLENGES.
By Tom Hundley
Tribune Foreign Correspondent
NAPLES, Italy -- Vesuvius has been quiet for the last 56 years.
Too quiet.
Perhaps if
the great volcano that looms over the city of Naples had let off
a little steam or belched a few tons of ash into the atmosphere
every now and then, Neapolitans would not be so nonchalant about
building their homes in its shadow.
But since
the last significant eruption in 1944, the population living on
the slopes of this live volcano has grown from about 200,000 to
nearly 700,000. About 3 million people live within a 10-mile radius
of Vesuvius's crater.
Scientists
agree on one thing: The volcano that buried Pompeii in 79 AD will
erupt again. When, with how much force and with how much warning
are the subjects of bitter dispute. For Italy's disaster planners,
Vesuvius is an Apocalypse waiting to happen.
An emergency
plan drawn up in 1995 calls for the calm and orderly evacuation
of about 600,000 people. But Neapolitans are notoriously un-calm
and disorderly.
Vesuvius is
under constant surveillance. Seismic probes ring the volcano's
perimeter. Satellites look for ground deformations. Tide gauges
and other instruments in the nearby Bay of Naples check for telltale
fluctuations in the sea level and water temperature. Gravimetric
devices record changes in ground density beneath the surface.
But Vesuvius
is giving no hint of its intentions.
"Nothing.
Absolutely nothing in the last twenty years," said Lucia
Civetta, director of the Vesuvius Observatory, which is responsible
for the round-the-clock monitoring of the volcano.
"Vesuvius
is characterized by long periods of rest that end in explosive
eruptions followed by periods of moderate activity. Now we are
in one of those periods of rest. We don't know how long it will
last," she said.
Civetta, however,
is confident that when Vesuvius is ready to awaken, it will give
at least 15 to 20 days advance notice.
"Vesuvius
is a volcano that does not erupt suddenly without showing signs
of unrest. We know from past history that in the period preceding
an eruption you have a lot of seismic activity and changes in
the water table. These precursors were always evident weeks and
sometimes months in advance," she said.
Franco Barberi,
director of Italy's civil defense department and a volcano expert,
shares Civetta's confidence.
"Ask
any scientist dealing with active volcanoes and he will tell you
that if a volcano is well-monitored, there is no way an eruption
can occur without precursor signs," he said.
But Giuseppe
Luongo, a leading volcano expert at Naples's Frederico II University
and a former director of the Vesuvius Observatory, points out
that while precursor signs may be evident for months, even years
in advance, pinpointing the moment the volcano will blow is tricky.
"From
a scientific standpoint, I think it is impossible to predict an
eruption 15 to 20 days in advance," he said.
"Montserrat?
No prediction. Pinatubo? No prediction. Rabaul? Maybe 12 hours
before the eruption," said Luongo, ticking off the names
of recent eruptions in the West Indies, the Philippines and New
Guinea where scientists have been less than successful in anticipating
volcanic behavior.
The current
eruption of Popocatepetl, the mighty volcano 40 miles southeast
of Mexico City, underscores the limits of science.
Popo, as it
is called, has been spewing and steaming with increasing intensity
for the last six years.
The Mexican
government has built a world-class monitoring network around it,
but even today, as huge molten rocks come hurtling out of its
mouth, scientists cannot say with certainty what is going to happen
next.
Popo also
underlines another problem facing emergency planners. Last week,
Mexican authorities ordered the evacuation of 40,000 people living
near the volcano. About 20,000 have moved into designated shelters;
the others refuse to budge.
The Vesuvius
evacuation plan is based on an eruption of the same magnitude
as the last great one, in 1631. It calls for nearly 700,000 people
to be evacuated to different regions of Italy by train, ferry
and automobile over a one-week period.
But given
the violent seismic activity that is expected to precede an eruption,
would trains still be running and would highways still be passable?
Would there be electrical power and a functioning communications
system? Would mass panic overtake the carefully scripted evacuation?
The tough
call for emergency planners is when to activate the plan.
Sound the
alarm too soon, said Luongo, and you have half the population
of Naples living in far-flung tent cities months, even years,
before an actual eruption occurs. Too late--well, Pompeii was
buried in less than 48 hours. The pyroclastic flow of a major
eruption would spill down the slopes and reach the coastal plane
in six minutes, wiping out everything in its path.
"It's
impossible to evacuate 700,000 people under such circumstances.
An evacuation is not a solution," Luongo said.
He suggested
a long-term relocation program that would gradually reduce the
population living on the slopes.
"In 20
or 30 years, you could reduce the population by half, but it is
necessary not to waste one more year, because every year brings
us closer to the probability of an eruption," he said.
The post-World
War II population explosion in Naples has fueled a parallel explosion
in illegal housing construction, much to the benefit of the Neapolitan
branch of the Mafia known as the Camorra.
Most of this
illegal construction is found along the coastal plane at the base
of Vesuvius. In recent years it has crept up the slopes to within
a mile and a half of the volcano's crater.
Finding the
political will to halt the illegal construction and move people
out of harm's way "is easy to say, very difficult to accomplish,"
civil protection chief Barberi said.
"You
are dealing with very high levels of organized crime. Year after
year, in spite of specific laws, people continue to build illegal
houses, even in the national park where it is strictly forbidden,"
he said.
The coastal
town of Torre del Greco, at the foot of Vesuvius, has been buried
by lava flows three times in 300 years, most recently in 1794.
That eruption wiped out half the town's population. But after
each catastrophe, the Torre del Greco has been rebuilt. Its bell
tower was built on top of the previous one.
At the end
of World War II, Torre del Greco had a population of 20,000. Today
it has mushroomed to over 100,000 and become part of greater Naples'
urban sprawl.
Mayor Romeo
del Giudice admits that his town had not done much in the way
of emergency preparation until October 1999 when it was jolted
by a harmless earthquake. Many feared it was a sign that Vesuvius
was beginning to stir.
The tremor
turned out to be a false alarm, but spurred Torre del Greco officials
to crack down on illegal construction and to launch a community
education program.
"We want
people to understand that it is not like we are living on top
of a bomb," del Giudice said. "We can co-exist with
the volcano, but everything depends on our behavior when the eruption
begins."
The plan calls
for Torre del Greco residents to be evacuated by ferry to Sicily.
Del Giudice said most residents would prefer to be evacuated closer
to home. He is not sure how they will react when the time comes.
"Scientists
might be able to predict a volcanic eruption, but it is much harder
to predict human behavior."
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