I’m interested to hear what information and opinions folks can share about this situation. Some reports are showing over 10k earthquakes in less than three weeks. I’ve done my best to collect information and there seems to be a division as to whether the cause is magmatic or tectonic. (thus I put this in IMHO instead of FQ)
There is obviously steam spurting out from the sides of the hills, so I don’t understand how it could be merely tectonic. It stands to reason that magma could be released by tectonic movement. Why not simply say “It’s both”?
As I understand it (and it’s been a while since the last time I was in that area, so I may be misremembering some details), there are only a few active volcanic spots in the islands. One of them is on Santorini, yes, but the caldera is submerged. More broadly, the more common geological activity in this region tends to be tectonic. When all the old volcanoes went extinct, an “arc” fault zone was left behind, which is where these tremors are generally found. So if they’re seeing steam, it’s probably a safe bet to assume something is happening with those faults, and not with the few remaining volcanoes.
(hang on, let me google something)
Okay, here’s an article that sort of confirms what I was remembering, but goes into a lot more detail. It’s also got an excellent map pinpointing the measured centers of the tremors.
There’s a clear cluster, and it’s away from the island proper. This points to something happening at, or under, one of the faults.
Could magma emerge? Sure, anything’s possible. This is a geologically complex area, and any time something major happens like this, we learn new stuff.
But the above seems to be why the experts are leaning — not confidently asserting, but leaning — toward tectonics over volcanics.
I’m interested to learn more, though, and will happily read more expert replies.
The last eruption at Santorini occured about 60-70 years ago, the spire that was created then is still observable. You can swim in a certain area inside the interior of the island where the water is about 105 degrees F, due to the thermal heat from the magma flow under the surface.
A second “seismic swarm” has begun in Italy. Close (by geological standards) and related. These plates are on the move, and they are showing their stress at magmatic points. Danger! Danger, Will Robinson!!
