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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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