The
extinct craters in Pozzuoli are part of an enormous
chain, now undersea, which runs out to the south on
the seabed in the direction of Sicily. The entire sea
between the Bay of Naples and Sicily thus contains its
own "Ring of Fire," so-called in analogy to the
mammoth ring of active volcanoes that perch on the
perimeter of the great Pacific tectonic plate.
Mt. Vesuvius has four undersea cousins to the south:
Palinuro, Vavilev, Marsili, and Magnaghi. The last
three were discovered in the 1950s…At present, there
is some concern about the state of "dormancy" of
Marsili. It is 3,000 meters high with the cone
reaching to 500 meters from the surface of the water.
Satellite cones of recent origin have been detected on
Marsili.
Newspapers and
recent comments on geology websites have been giving some
attention to one of the “four undersea cousins” of
Vesuvius; to wit, Mt. Marsili. No one has quite shouted
“Thar she blows!” but comments include everything from the
cautionary “This is active” to the alarmist “This thing
could erupt at any time!”
Mt. Marsili (named for Italian naturalist Luigi F. Marsili
[1658-1730] is a pretty good candidate for the best answer
to the question, “What is the largest active European
volcano?” depending, of course, on how you define
“European” (mainland? islands? undersea?) and “active”
(when was the last eruption?). Those are quiz-show
quibbles, though. Even Etna is on an island (Sicily) as
are the smaller still very active volcanoes* of
Stromboli, Vulcano, and Lipari in the Aeolian archipelago
just above Sicily; Vesuvius is dormant (or just snoozing a
bit) and the Solfatara sulphur pit in Pozzuoli is a
volcano only to geologists, and what do they know? (I
mean, these are the guys who tell you the world is older
than 7,000 years!)
*update from July 4, 2019: Stromboli erupted yesterday (image
shown). The Italian National Institute
of Geophysics and Volcanology (INGV) called it
a "paroxysmal eruption,"high-pressure magma exploding from a
shallow, underground reservoir. Such eruptions
are rare, but Stromboli is one of the most active
volcanoes on the planet and has been erupting almost
continuously since 1932. This does not keep
tourists from scaling the 3,000 ft/c.1000 mtr summit
(about the height of Mt. Vesuvius in Naples). One small
inhabited area, Ginostra was overtaken by fire, ash and
cinders. Dozens were evacuated by motor launches and
ferries sent from other Aeolian islands. Thirty tourists
jumped into the sea for safety. There was one
fatality, unfortunately: a young man resident in
Sicily, in training to become an officer in the
merchant marine, and on the island to hike and climb
Stromboli. He was killed by falling stones.
In any event, Marsili is a seamount volcano (that is,
submerged) in the same Aeolian volcanic arc as the islands
mentioned above. Marsili is right above those islands and
175 kilometers (109 miles) south of Naples (see map,
above). Be glad you can’t see this thing; the seamount is
3,000 meters tall (almost 10,000 feet), about the same as
Etna. The long axis of the volcanic structure (really two
adjacent mounts) is NNE-SSW; the base is 70 km by 30 km (
43 x 25 miles). The cone reaches to fewer than 500 meters
from the surface of the water. Marsili is described as a
fragile-walled structure, made of low-density and unstable
rock, fed by an underlying shallow magma chamber. Although
older reports said there had been no eruptions in historic
times, the Italian National Institute of Geophysics and
Volcanology announced in 2010 that Marsili could erupt "at
any time," and might experience a catastrophic collapse.
Vast amounts of magma would be released in an undersea
eruption and a landslide that might trigger destructive
tsunamis on the Italian coast. That report was a few years
ago and made some headlines. Of course, "at any time" to a
writer of headlines (motto: Scare the crap out of
people today!) means tomorrow or the day
after; anything beyond that is old dead junk. Thus, they
have jumped on a more recent report from an oceanographic
study by the National Interuniversity Consortium for Sea
Sciences; the report says that studies of sediment and
fossil remains show that the volcano has indeed been
active in historic times—within the last 3,000-5,000
years. At least, says the report, Marsili should be moved
“up” into the class of volcanoes such as the smaller ones
in the Aeolians.
The good news is that while gloom-and-doom seers see vast
devastation, you are free to see a new island rising,
roaring up Atlantis-like from the deep. No one will have
to be evacuated, and think of all the new land available
for time-share condos. Call me a dreamer.
update: January 18,
2014 - This note from good friend and
geologist, Peter Humphrey:
Wonder if they have a 3-axis seismometer
down there with a cable to a surface buoy for satellite
uplink! Is this guaranteed Italian territory if it
surfaces --or the first drunken fisherman who plants a
flag? We have never seen a volcano surface outside
of 12 nautical miles, though the Japanese did lose an
old one to drowning. Rather than losing that
exclusive economic zone, they sent out an armada of
giant concrete jax to keep it above water!
Likewise, this would receive its own EEZ.*
*note: Friend Peter is
referring to EEZ-Exclusive Economic Zone (EEZ), a seazone
prescribed by the United Nations Convention on the Law of
the Sea; the convention grants special rights over the
exploration and use of marine resources, including energy
production from water and wind. The EEZ stretches 200
nautical miles from a nation's coast-line. Not so fast,
you say; the Med-bounding nations are so close to
one another that every EEZ would overlap every other EEZ.
Hmmmm, maybe that is why until quite recently no nation
with a Mediterranean coast line has bothered to claim an
EEZ. They would just have a war. Recently, some countries
have proclaimed such things as Ecological Protection Zones
to protect their marine resources. Italy did that in 2006,
so I think we could keep Peter's "first drunken fisherman"
from raising a private flag over the new island sovereign
nation of Marsilonia & Guido's Pizzeria by claiming
that a sea-mount volcano is by definition a marine
resource and though beyond Italy's 12-mile limit, is well
within the extended purview of an ecological protection
act. Since Marsilonia is a physical extension of the
volcano, the island, too, is protected. The island
would be part of Italy.Quod erat demonstrandum
ipso facto et cetera.
That area
of the "Ring of Fire" has at least one comic-opera-type
episode connected with it. During the night of June 27,
1831, a small island surfaced off the coast of Sciacca,
near Agrigento in southern Sicily. English, French and
Neapolitan vessels raced to the scene to claim the
island. The Neapolitans won and hoisted the flag of the
Kingdom of the Two Sicilies, naming the new acquisition
"Ferdinandea" for their King Ferdinand. Unfortunately
for the bureaucrats and would-be colonizers, the island
disappeared a few months later. Fortunately for
21st-century scuba divers, however, the island didn't
sink that far, and now a good-sized underwater nature
reserve thrives about 30 feet below the surface. The
"Ferdinandea" episode made the papers in the summer of
2002 due to recent rumblings and small "seismic events"
in the area. Active fumaroles are venting from the
slopes of the sunken island. Is the island about to
resurface? Probably not, say local geologists — but
these are the same people who call earth- and seaquakes
"seismic events." Time will tell.