Scientists have uncovered a massive ancient geological feature beneath the Midwestern United States — a billion-year-old rift ...

The Mount St. Helens eruption anniversary prompts investigation into the California earthquakes: eruption history, threat ...

Over the Sierra crest — about 150 miles to the east of Manteca, Oakdale, and Turlock — is one of the world’s largest active ...

Geoscientists have discovered a magma cap at Yellowstone National Park that is likely playing a critical role in preventing a ...

Non-explosive eruptions over the last half-million years produced the large, shield-shaped Medicine Lake Volcano. A shallow, but wide caldera basin containing its namesake lake is at the summit ...