Search results
Results from the WOW.Com Content Network
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]
A fissure vent, also known as a volcanic fissure, eruption fissure or simply a fissure, is a linear volcanic vent through which lava erupts, usually without any explosive activity. The vent is often a few metres wide and may be many kilometres long. Fissure vents can cause large flood basalts which run first in lava channels and later in lava ...
Deposits near the source vent consist of large volcanic blocks and bombs, with so-called "bread-crust bombs" being especially common. These deeply cracked volcanic chunks form when the exterior of ejected lava cools quickly into a glassy or fine-grained shell, but the inside continues to cool and vesiculate. The center of the fragment expands ...
A volcanic crater is an approximately circular depression in the ground caused by volcanic activity. [1] It is typically a bowl-shaped feature containing one or more vents. During volcanic eruptions , molten magma and volcanic gases rise from an underground magma chamber , through a conduit, until they reach the crater's vent, from where the ...
A volcanic fissure and lava channel. A fissure vent, also known as a volcanic fissure or eruption fissure, is a long volcanic vent through which lava erupts. Fissure vents are connected to deep magma reservoirs and are typically found in and along rifts and rift zones. [14] They are commonly associated with shield volcanoes.
A fumarole (or fumerole) [1] is a vent in the surface of the Earth or another rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcanic activity , but fumarole activity can also precede a volcanic eruption and has been used for ...
Volcanic gases are gases given off by active (or, at times, by dormant) volcanoes. These include gases trapped in cavities in volcanic rocks, dissolved or dissociated gases in magma and lava, or gases emanating from lava, from volcanic craters or vents. Volcanic gases can also be emitted through groundwater heated by volcanic action.
A volcanic field is an area of Earth's crust that is prone to localized volcanic activity. The type and number of volcanoes required to be called a "field" is not well-defined. [ 1 ] Volcanic fields usually consist of clusters of up to 100 volcanoes such as cinder cones .