On Monday, Italy’s Stromboli volcano fired ash hundreds of feet into the air and launched a pyroclastic flow tumbling down its slope, according to Italy’s Istituto Nazionale Geofisica e Vulcanologia (INGV).
The sparsely inhabited volcanic island, one of seven islands that make up the Aeolian archipelago off Sicily’s northern coast, is among the most active volcanoes in the world and has been spewing glowing lava from its crater consistently for at least 2,000 years—earning it the nickname the “lighthouse of the Mediterranean,” wrote Giannella M. Garrett for National Geographic in 2019.
This latest eruption was larger and more violent than Stromboli’s typical volcanic activity, reports Stephanie Pappas for Live Science. The plume of ash and subsequent pyroclastic flow—something like an avalanche of superheated ash, lava fragments and gas flowing downhill—were caught on tape by INGV cameras.
Stromboli’s usual low-energy eruptions are so consistent that volcanologists actually refer to similar volcanism as Strombolian activity. But, as with this latest eruption, Stromboli has been known to occasionally buck that trend in events known as Strombolian paroxysms.
A paper published last month in the journal Scientific Reports catalogued 180 of the Italian volcano’s paroxysms over the last 140 years. Though researchers still don’t fully understand the geophysical processes that drive Stromboli’s most destructive activity, statistical analysis of the timing of the paroxysms may help quantify the probability of a powerful eruption at a given time.
According to a statement, the researchers found that paroxysms often occur in clusters. The team estimates that there is a 50 percent probability that a second Stromboli paroxysm will follow the first explosion within 12 months, and a 20 percent chance that it will occur less than two months later. But there is also a 10 percent probability that the volcano will resume its normal programming for more than ten years following a paroxysm.
These odds are borne out by this latest high-intensity eruption, which triggered a collapse in the crater area and showered the island with ash, according to Volcano Discovery. Another more powerful than usual eruption occurred just six days prior, and the summer of 2019 was marked by several large explosions—one of which resulted in the death of a hiker who was struck by ejected debris lower on the volcano’s flanks, per Smithsonian’s Global Volcanism Program. Following 2019’s deadly eruption, hikers and tour groups were barred from treading higher than 950 feet up the volcano’s slope, according to National Geographic.
Per Live Science, it’s unclear whether the recent cluster of paroxysms represents the start of a trend towards increased average activity or will prove to be an isolated bout of more intense eruptions.
Fortunately, as of this writing there have been no reported damages to the homes of the few hundred people who reside on the island following this latest eruption.