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A volcano needs a reservoir of molten magma (e.g. a magma chamber), a conduit to allow magma to rise through the crust, and a vent to allow the magma to escape above the surface as lava. The erupted volcanic material (lava and tephra) that is deposited around the vent is known as a volcanic edifice, typically a volcanic cone or mountain. [2] [22]
Hotspot volcanoes are considered to have a fundamentally different origin from island arc volcanoes. The latter form over subduction zones, at converging plate boundaries. When one oceanic plate meets another, the denser plate is forced downward into a deep ocean trench.
Often, a volcano may have a deep magma chamber many kilometers down, which supplies a shallower chamber near the summit. The location of magma chambers can be mapped using seismology : seismic waves from earthquakes move more slowly through liquid rock than solid, allowing measurements to pinpoint the regions of slow movement which identify ...
Plinian eruption: 1: ash plume; 2: magma conduit; 3: volcanic ash fall; 4: layers of lava and ash; 5: stratum; 6: magma chamber 1822 artist's impression of the eruption of Mount Vesuvius in 79, depicting what the AD 79 eruption may have looked like, by the English geologist George Julius Poulett Scrope.
A diagram of a destructive plate margin, where subduction fuels volcanic activity at the subduction zones of tectonic plate boundaries. In 1841, the first volcanological observatory, the Vesuvius Observatory, was founded in the Kingdom of the Two Sicilies. [1]
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.
Diagram of the geological process of subduction. ... From the Seafloor to the Volcano's Top Video about the work of the Collaborative Research Center (SFB) ...
The latter may be directly accessible in the eroded portions of active volcanoes or, more commonly, in extinct eroded volcanoes. The general aim of Volcano-Tectonics is to capture the shallower and deeper structure of volcanoes, establishing the overall stress-strain relationships between the magma and the host rock, to ultimately understand ...