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Schematic of the internal structure of a typical cinder cone. A cinder cone (or scoria cone [1]) is a steep conical hill of loose pyroclastic fragments, such as volcanic clinkers, volcanic ash, or scoria that has been built around a volcanic vent.
The internal structure of Earth are the layers of the Earth, excluding its atmosphere and hydrosphere. The structure consists of an outer silicate solid crust , a highly viscous asthenosphere , and solid mantle , a liquid outer core whose flow generates the Earth's magnetic field , and a solid inner core .
Augustine Volcano (Alaska) during its eruptive phase on January 24, 2006. A volcano is commonly defined as a vent or fissure 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.
The vast majority of the world's active volcanoes occur along plate boundaries, with the Pacific plate's Ring of Fire being the most active and widely known. Some volcanoes occur in the interiors of plates, and these have been variously attributed to internal plate deformation [15] and to mantle plumes.
A diagram of the internal structure of Earth. The lithosphere consists of the crust and upper solid mantle (lithospheric mantle). The green dashed line marks the LAB. The lithosphere–asthenosphere boundary (referred to as the LAB by geophysicists) represents a mechanical difference between layers in Earth's inner structure.
[75] [27] The central shield volcano is the oldest, built mostly from 22 to 18 Ma but with a later phase from 17.5 to 13 Ma. The southern shield volcano formed from 21 to 14 Ma. The northern shield volcano was built mainly from 17 to 12 Ma. [76] These shield volcanoes erupted mostly basaltic and trachybasaltic lava flows. [27]
A tuff ring is a related type of small monogenetic volcano that is also produced by phreatic (hydrovolcanic) explosions directly associated with magma brought to the surface through a conduit from a deep-seated magma reservoir. They are characterized by rims that have a low, broad topographic profiles and gentle topographic slopes that are 25 ...
A stratovolcano, also known as a composite volcano, is a typically conical volcano built up by many alternating layers of hardened lava and tephra. [1] Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and explosive eruptions. [2] Some have collapsed summit craters called calderas. [3]