Entire Volcano in California is "Moving" – Quakes May Signal Trouble When people think of California, they may think of Earthquakes. Most folks don't even know there are volcanoes there, but there are. At least two: Lassen Peak and the much larger Long Valley Caldera near Mammoth Lakes. In 1915, Lassen Peak erupted and wrecked a huge portion of the state. Over the last 100 days, the much larger Long Valley Caldera has begun acting-up. And what it's doing has Geologists at the US Geological Survey "concerned." The Caldera – the mouth of the Volcano – is . . . . moving. According to scientific instruments monitored by the United States Geological Survey (USGS) the area in vicinity of the Long Valley caldera is deforming and moving rapidly compared to previous records. How sure are they? "95% (confidence interval), the (data) ensemble is significant" The data is showing on a recent timespan that the amount of movement is causing STATISTICALLY SIGNIFICANT STRAIN in the rock in the area.