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,
Tenorio Volcano National Park Dantas Trail, which winds up the volcano and passes through forested terrain before eventually reaching the peak. Tenorio Volcano National Park Tenorio Volcano National Park () is a National Park in the northern part of Costa Rica, which forms part of the Arenal Tilaran Conservation Area. The jewel of the National Park is the volcano, from which it receives its name. The Tenorio Volcano was made part of the National Park in 1995 and is located about 26 miles northeast from the town of Fortuna in the Guanacaste Province. Tenorio Volcano consists of four volcanic peaks and two craters. One