Then Santorini blew.
I was reminded of that today, as newspapers tells us that the Yellowstone caldera is rising. I liked the Ars Technica summary:
Yellowstone rechargesIf Yellowstone were to erupt there are a lot of things Americans could stop worrying about.
It's important to emphasize that, even though this activity is clearly significant, it's not a sign that you should stop saving for retirement. "Although the geodetic observations and models do not imply an impending volcanic eruption or hydrothermal explosion, they are important evidence of ongoing processes of a large caldera that was produced by a supervolcano eruption." For now, it appears that Yellowstone is just reminding us that it's worth paying attention to.
Happily, there's no sign of that happening anytime soon:
...The team is quick to reassure that no eruption looms; there are no seismic harbingers. Instead, earthquake activity in the valley has dropped by half to fewer than 1000 tremors a year. Somehow, faster uplift and fewer earthquakes are related to what's going on some 80 kilometers below Yellowstone, where a plume of magma fuels the area's famous geothermal activity...Basically we're seeing the giant inhale. Eventually he'll gently exhale.
Just as long as doesn't sneeze.