When individuals hear volcanoes, they tend to envision blazing eruptions blasting into the air. However, volcanoes can also collapse sideways, with their sides, or flanks, collapsing. Such a collapse ...

The type of volcanic eruption and the variety of volcano that forms depends in large part on the composition of the magma at the time of the eruption. Please read the background information about the ...

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 ...