Most volcanoes form at the boundaries of Earth's tectonic plates, which are huge slabs of crust and upper mantle that fit together like puzzle pieces. Think of these plates as massive rafts floating ...

California has seven active volcanoes, each with a unique eruption history, categorized by type and threat level. The USGS monitors these volcanoes, providing information to authorities and the public ...

Is there anything more spectacular than a towering lava fountain? Think about what it is: glowing red molten rock being shot into the sky, potentially hundreds or thousands of feet. As ubiquitous and ...