The Long Valley Caldera, located in California, experienced a mini-swarm of earthquakes on Thursday. While none of the quakes were above 3.0 on the Richter scale, the fact that at least nine measurable ground-shakers occurred in such a condensed period of time was enough to cause a slight rise of alert-levels for the area.
The caldera has experienced various swarms of earthquakes since May 1980, when a strong swarm included four quakes hitting at 6.0 of greater; this event caused a substantial dome-shaped ground-rise a 10 inches (25 centimeters) in the region. While activity since then has been sporadic it has also been persistent, causing scientists to monitor the caldera closely.
Long Valley is ranked a 'seven' on the Volcanic Explosivity Index [VEI] scale. This marks it as an ultra-Plinian volcano, one level below super-volcanoes like the well-known Yellowstone Caldera.
Observation: As is apt to happen in my world, events follow ideas. The fact this came about one day after my article on Plan and Prep, The Sevens - Ultra-Plinian Volcanoes, was posted... yeah, that is odd to say the least. Click on the link to learn more about VEI 7 volcanoes, and why we should be concerned about them - SB.