Alaska Century Old Ash Cloud

This Aug. 20, 2010 photo provided by the U.S. Geological Survey shows the lava dome named Novarupta marks the 1.2 mile (2 km) wide vent of the 1912 Novarupta-Katmai eruption. While western U.S. states were suffering from hazy red skies from wildfires, Alaska was dealing with an air quality problem born a century ago. Strong southerly winds picked up loose ash from a 1912 volcanic eruption, sending an ash cloud about 4,000 feet into the sky. (Peter Kelly/U.S. Geological Survey via AP)