Whats a hydrothermal explosion?
Hydrothermal explosions occur when water that feeds Yellowstone’s geysers and hot springs is explosively flashed to steam, breaking rocks and throwing them into the air. Small hydrothermal explosion events occur every few years at Yellowstone, mostly in the geyser basins, and usually pose little hazard. There is geologic evidence for a few large hydrothermal explosions, some leaving craters thousands of feet across near Yellowstone Lake and in other areas of the park. Such large explosions have not occurred within the last several thousand years. Two classic papers discuss evidence for hydrothermal explosions at Yellowstone, both in the geyser basins (Muffler et al., 1971) and beneath Mary Bay in Yellowstone Lake (Wold et al., 1977).
