California Supervolcano Alert 🌋 A new earthquake swarm is shaking Mammoth Lakes, and USGS CalVO lists ongoing volcanic unrest signals in the Long Valley Caldera, a 20-mile-wide volcanic system capable of very large eruptions in geologic time. The last true super-eruption here (the Bishop Tuff, ~767,000 years ago) was roughly 600 times larger than 1980 Mount St. Helens. The magma system still exists, and the caldera continues to release toxic CO₂ at Horseshoe Lake, which has killed trees by suff