One of the most explosive volcanoes in U.S. history began its eruption with a trickle, not a blast. Mount St. Helens' gas-laden magma oozed into the cone before the mountain finally erupted in 1980.

For much of 2025, an underwater volcano off the Oregon coast was treated as a geological ticking clock, with forecasts suggesting it could erupt at almost any moment. Instead, the year is ending ...