[Rockhounds] Two supervolcanoes, a world apart, have the attention of scientists

[Kreigh Tomaszewski]

Two long-dormant “supervolcanoes” on two separate continents appear to be
stirring to life. Well, maybe.

In recent months, more than a thousand minor earthquakes have rattled the
area around the Campi Flegrei volcano in southern Italy, stoking fears that
it may soon erupt again after nearly five centuries. Some 6,000 miles away,
scientists have for decades recorded similarly small earthquakes and
instances of ground deformation at the Long Valley Caldera, a volcano in
eastern California that sits adjacent to Mammoth Mountain.

But does all this seismic unrest really portend a volcanic eruption
<https://www.nbcnews.com/video/lava-spews-into-the-air-after-volcano-erupts-in-southwest-iceland-187614789745>?
It sort of depends on whom you ask.

Most experts say there is no immediate threat of an eruption at either Long
Valley or Campi Flegrei. Both volcanoes are calderas — sprawling
depressions created long ago by violent “super-eruptions” that essentially
collapsed in on themselves — which are often more challenging to forecast
compared to the large mountain-shaped features that people typically
imagine when they think of volcanoes.

Seismic unrest can be a sign that a volcano is waking up, but the full
story is much more complex.

https://www.nbcnews.com/science/science-news/supervolcanoes-earthquakes-flegrei-long-valley-caldera-rcna121781