Mt. St. Helen

When Mount St. Helens erupted on May 18, 1980, huge quantities of volcanic ash were blown into the atmosphere. This satellite image was taken less than eight hours after the eruption. The ash cloud had already spread as far as western Montana. Volcanic ash has little long-term impact on global climate because it settles quickly from the air. A more significant factor affecting climate is the quantity of sulfur dioxide gas emitted during an eruption.