Is the World's Largest Volcano Getting Ready to Erupt?

No volcano on Earth is as large as Mauna Loa on the big island of Hawai'i. The giant edifice rises from sea level to over 13,700 feet ... but that is only the top of the volcano. If you count the parts of Mauna Loa below the Pacific Ocean, it towers over 29,000 feet from bottom to top -- as tall as Mount Everest. Yet, for anyone under 40, Mauna Loa is seen as a quiet volcano. The last eruption ended in 1984 and since then, Kīlauea has been the star of the Hawaiian volcanoes. However, signs at Mauna Loa suggest that things could be changing.