Iceland's volcano has been much in the news lately, but you probably have not seen this photo of a plume of volcanic ash rising into the air. This is an old photo, and the volcanic activity is not new. Krakatoa exploded on August 27, 1883, and last year I wrote about Simon Winchester's book Krakatoa: The Day the World Exploded, which I read when it was first published in 2003. That eruption in Indonesia was one of the most catastrophic ever witnessed in recorded history, with some of the tremendous explosions from the island of Krakatoa being heard 2,200 miles (3,540 kilometers) away in Australia. Read more of my thoughts here.