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A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. [1] Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and periodic intervals of explosive eruptions and effusive eruptions, although some have collapsed summit ...
Some of the eruptive structures formed during volcanic activity (counterclockwise): a Plinian eruption column, Hawaiian pahoehoe flows, and a lava arc from a Strombolian eruption. Several types of volcanic eruptions —during which material is expelled from a volcanic vent or fissure —have been distinguished by volcanologists.
In essence, fractional crystallization is the removal of early formed crystals from an originally homogeneous magma (for example, by gravity settling) so that these crystals are prevented from further reaction with the residual melt. [3] The composition of the remaining melt becomes relatively depleted in some components and enriched in others ...
Magma that cools slowly within a magma chamber usually ends up forming bodies of plutonic rocks such as gabbro, diorite and granite, depending upon the composition of the magma. Alternatively, if the magma is erupted it forms volcanic rocks such as basalt , andesite and rhyolite (the extrusive equivalents of gabbro, diorite and granite ...
Before the eruption, Aniakchak was a 2,300 meters (7,500 ft) high [117] deeply eroded stratovolcano [118] with two separate magma bodies, one andesitic and the other rhyodacitic, under Aniakchak at least 4.1–5.5 kilometers (2.5–3.4 mi) in depth. [63] These two magma bodies had evolved independently in the time before the eruption. [119]
A magma chamber is a large pool of liquid rock beneath the surface of the Earth. The molten rock, or magma, in such a chamber is less dense than the surrounding country rock, which produces buoyant forces on the magma that tend to drive it upwards. [1] If the magma finds a path to the surface, then the result will be a volcanic eruption ...
VEI. 5. Impact. Buried the Roman settlements of Pompeii, Herculaneum, Oplontis, and Stabiae. Deaths. 1,500–3,500, possibly up to 16,000 [1][note 1] Of the many eruptions of Mount Vesuvius, a major stratovolcano in Southern Italy, the best-known is its eruption in 79 AD, [2][3] which was one of the deadliest in history.
Phreatomagmatic eruptions are volcanic eruptions resulting from interaction between magma and water. They differ from exclusively magmatic eruptions and phreatic eruptions. Unlike phreatic eruptions, the products of phreatomagmatic eruptions contain juvenile (magmatic) clasts. [1] It is common for a large explosive eruption to have magmatic and ...