short note on volcanicity
Answers
Answer:
volcanicity (countable and uncountable, plural volcanicities) The quality or state of being volcanic. The level of power of a volcano.
Explanation:
A volcano is a mountain that has lava (hot, liquid rock) coming out from a magma chamber under the ground, or did have in the past. Volcanoes[1] are formed by the movement of tectonic plates.
Mount St. Helens erupting on May 18, 1980
Spectacular and beautiful Koryaksky volcano on the Kamchatka peninsula, eastern Russia
The Earth's crust is broken into 17 major, rigid tectonic plates. These float on a hotter, softer layer in its mantle.[2] Volcanoes are often found where tectonic plates are moving apart or coming together. Volcanoes can also form where there is stretching and thinning of the crust's plates, e.g., in the East African Rift.[3] Volcanoes are usually not found where two tectonic plates slide past one another.
Volcanism away from plate boundaries is caused by mantle plumes. These so-called "hotspots", for example Hawaii, are thought to arise from upwelling magma from the core–mantle boundary, 3,000 km deep in the Earth.
Most volcanoes have a volcanic crater at the top. When a volcano is active, materials come out of it. The materials include lava, steam, gaseous sulfur compounds, ash and broken rock pieces.