Plot comparing caldera deformation

Vertical deformation measured at three caldera systems: Yellowstone, Wyoming (red), Long Valley, California (green), and Campi Flegrei, Italy (blue).  Triangles show data collected by leveling, and circles by GPS.  All three calderas have gone up and down over time, but the scale of change at Campi Flegrei dwarfs that at Long Valley and Yellowstone.  Campi Flegrei data courtesy of Prospero De Martino (INGV-OV).