Volcano near Rome
July 2016 – ROME, Italy – The
country of Italy, home to one of the most famous volcanic disasters in
history, is showing signs that another massive eruption is brewing,
according to a new study published in the journal Geophysical Research Letters.
Almost 2,000 years after the burial of Pompeii and nearby Herculaneum
during the eruption of Mt. Vesuvius in 79 A.D., an ancient volcano near
Rome is rumbling to life, say scientists. About 19 miles away from the
heart of Rome, an ancient volcanic district called the Colli Albani is
stirring. The Colli Albani, a 9-mile-long semicircle of hills on the
outskirts of Rome, last erupted 36,000 years ago, so geologists had
classified it as extinct – until about 20 years ago.
In the early 1990s, the area around the
Colli Albani Volcanic District began showing geological indicators of a
future explosion: ground levels shifted, steam vents opened, and
earthquakes shook the hills around the site. Since that time, scientists
have used these symptoms, along with satellite data and information
about the volcano’s previous eruptions, to evaluate the risk that the
Colli Albani poses to the surrounding region.
The increase in earthquakes (many of
which occurred during an “earthquake swarm” between 1991 and 1995) and
ground level changes in the region indicate the presence of a magma
bubble forming beneath the earth near Colli Albani, pushing upwards
until it can erupt. Using historical data, researchers determined that
Colli Albani is not extinct, as was long believed – it merely operates
on a 31,000-year cycle of dormancy and wakefulness. And when the volcano
is awake, scientists say, it is dangerous.
Over the last 200,000 years, scientists
say that the region surrounding the Colli Albani has risen by 164 feet,
and it continues to rise by nearly an inch per year, indicating that
the magma bubble is still growing. For thousands of years, the magma
bubble has been trapped by pieces of land that have now begun sliding
against each other. If those pieces shift enough, Colli Albani will
erupt.
When conditions are right (or, from a
human perspective, terribly, terribly wrong), Colli Albani can produce
eruptions similar to the one that destroyed Pompeii and Herculaneum in
79 AD. Like Vesuvius, Colli Albani could erupt with a towering cloud of
burning ash and showers of heated “lava bombs” that could damage or
destroy nearby towns. Past eruptions have also seen swift streams of
lava, scientists say, where Roman suburbs now cluster. A future eruption
could devastate them. Rome itself would be safe from such an eruption
in all but the very worst of circumstances. If the wind is blowing in
the right direction, it could steer an ash cloud from Colli Albani
towards the heart of the city.
The good news, according to
researchers, is that time is on Rome’s side. The study’s lead author,
Fabrizio Marra, a volcanologist at the National Institute of Geophysics
and Volcanology in Rome, told the American Geological Union that he does
not expect the Colli Albani to erupt for another 1,000 years. “We
expect for sure some initial stages which may not be so explosive,” said
Dr. Marra, “but it may evolve in time.” –Christian Science Monitor
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