Volcano were proposed for volcano behavior before the modern understanding of the Earth's mantle structure as a semisolid material was developed. For decades after awareness that compression and radioactive materials may be heat sources, their contributions were specifically discounted. Volcanic action was often attributed to chemical reactions and a thin layer of molten rock near the surface. Volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. Earth's volcanoes occur because its crust is broken into 17 major,
Mud volcano abyssal plains. Most liquid and solid material is released during eruptions, but seeps occur during dormant periods. The mud is rich in halite (rock salt). First-order estimates of mud volcano emissions have been made (1 Tg = 1 million metric tonnes). Dozens of mud volcanoes can be found on the Taman Peninsula of Russia and the Kerch Peninsula of Crimea along with the south-western portion of Bulgaria near Rupite. In Italy, they are common in the northern front of the Apennines and in Sicily. On August 24, 2013, a mud volcano appeared in the centre of the via Coccia di