The world's largest acidic geyser has begun erupting again in Yellowstone after slumbering for over five years, the national park said Monday. MAMMOTH HOT SPRINGS, Wyo. - The world's largest acidic geyser has begun erupting again in Yellowstone after slumbering for over five years, the national park said Monday. Echinus Geyser, located in the back basin of the Norris Geyser Basin at Yellows... [2063 chars]