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A volcanic plug, also called a volcanic neck or lava neck, is a volcanic object created when magma hardens within a vent on an active volcano. When present, a plug can cause an extreme build-up of high gas pressure if rising volatile -charged magma is trapped beneath it, and this can sometimes lead to an explosive eruption.
Volcanic lightning is an electrical discharge caused by a volcanic eruption rather than from an ordinary thunderstorm. Volcanic lightning arises from colliding, fragmenting particles of volcanic ash (and sometimes ice ), [ 1 ] [ 2 ] which generate static electricity within the volcanic plume , [ 3 ] leading to the name dirty thunderstorm .
After magma is generated, it will travel across the crust and lead to the formation of magma conduits and chambers. In continental crust, partial melting occurs when a portion of the solid rock melts into felsic magma. [4] Rocks in the lower crust and the upper mantle are subject to partial melting.
Rhyolite is an extrusive igneous rock, formed from magma rich in silica that is extruded from a volcanic vent to cool quickly on the surface rather than slowly in the subsurface. It is generally light in color due to its low content of mafic minerals, and it is typically very fine-grained or glassy. [5]
The English designation Agathla is derived from the Navajo name aghaałą́ meaning 'much wool', apparently for the fur of antelope and deer accumulating on the rock. [3] The mountain is considered sacred by the Navajo. Agathla Peak is an eroded volcanic plug consisting of volcanic breccia cut by dikes of an unusual igneous rock called minette.
Super volcano is the term used to describe volcanoes that have gradually over time built up immense amounts of magma and could wreak havoc if ejected onto the planet's surface. And in the heart of ...
When felsic domes form, they are emplaced within and on top of the conduit. [16] If a dome forms and crystallizes enough early in an eruption, it acts as a plug on the system, [16] denying the main mechanism of degassing. If this happens, it is common that the eruption will change from effusive to explosive, due to pressure build up below the ...
Civil defense personnel are on high alert, blocking access to the road leading to the mountain, and flying in a helicopter over the lava floes to monitor volcanic activity.