Volcanic Features
The most common perception of a volcano is of a conical mountain, spewing lava and poisonous gases from a crater at its summit. This describes just one of many types of volcano, and the features of volcanoes are much more complicated. The structure and behavior of volcanoes depends on a number of factors. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater, whereas others present landscape features such as massive plateaus. Vents that issue volcanic material (lava, which is what magma is called once it has escaped to the surface, and ash) and gases (mainly steam and magmatic gases) can be located anywhere on the landform. Many of these vents give rise to smaller cones such as Puʻu ʻŌʻō on a flank of Hawaii's Kīlauea. Other types of volcano include cryovolcanoes (or ice volcanoes), particularly on some moons of Jupiter, Saturn and Neptune; and mud volcanoes, which are formations often not associated with known magmatic activity. Active mud volcanoes tend to involve temperatures much lower than those of igneous volcanoes, except when a mud volcano is actually a vent of an igneous volcano.
Read more about this topic: Extinct Volcanoes
Famous quotes containing the words volcanic and/or features:
“Each of us, even the lowliest and most insignificant among us, was uprooted from his innermost existence by the almost constant volcanic upheavals visited upon our European soil and, as one of countless human beings, I can’t claim any special place for myself except that, as an Austrian, a Jew, writer, humanist and pacifist, I have always been precisely in those places where the effects of the thrusts were most violent.”
—Stefan Zweig (18811942)
“The features of our face are hardly more than gestures which force of habit made permanent. Nature, like the destruction of Pompeii, like the metamorphosis of a nymph into a tree, has arrested us in an accustomed movement.”
—Marcel Proust (1871–1922)