Volcano | Definition, Types, & Facts | Britannica
2024年10月7日 · volcano, vent in the crust of Earth or another planet or satellite, from which issue eruptions of molten rock, hot rock fragments, and hot gases. A volcanic eruption is an awesome display of Earth’s power. Yet, while eruptions are spectacular to watch, they can cause disastrous loss of life and property, especially in densely populated ...
Volcanic eruption | Description, History, Mythology, & Facts
A volcanic eruption is an eruption of molten rock, hot rock fragments, and hot gases through a volcano, which is a vent in a planet’s or satellite’s crust. Volcanic eruptions can cause disastrous loss of life and property.
Volcanism | Examples, Effects, & Facts | Britannica
Volcanism, any of various processes and phenomena associated with the surficial discharge of molten rock, pyroclastic fragments, or hot water and steam, including volcanoes, geysers, and fumaroles.
Volcano - Eruptions, Types, Magma | Britannica
2024年10月7日 · The different types of volcanic activity can best be understood by making comparisons, and in this section two specific eruptions are compared—the 1991 eruption of Mount Pinatubo (a classic example of explosive volcanism) and the 1984 eruption of Mauna Loa (illustrative of effusive volcanism).
Volcanology | Eruptions, Magma, Lava | Britannica
Volcanology, discipline of the geologic sciences that is concerned with all aspects of volcanic phenomena. Volcanology deals with the formation, distribution, and classification of volcanoes as well as with their structure and the kinds of materials ejected …
volcano - Students | Britannica Kids | Homework Help
Volcanoes occur mainly near the boundaries of the tectonic plates that make up Earth’s surface layer. They form along belts of tension, where plates diverge, and along belts of compression, where plates converge. Nearly 1,900 volcanoes are active today or are known to have been active in historical times.
Volcano - Eruptions, Cone, Magma | Britannica
2024年10月7日 · Volcano - Eruptions, Cone, Magma: Stratovolcanoes such as Mayon Volcano in the Philippines, Mount Momotombo in Nicaragua, and Ol Doinyo Lengai in Tanzania are steep cones built by both pyroclastic and lava-flow eruptions.
volcano - Kids | Britannica Kids | Homework Help
When a volcano erupts, hot gases and melted rock from deep within Earth find their way up to the surface. This material may flow slowly out of a fissure, or crack, in the ground, or it may explode suddenly into the air. Volcanic eruptions may be very …
Volcano - Calderas, Magma, Eruptions | Britannica
2024年10月7日 · Volcano - Calderas, Magma, Eruptions: Most calderas—large circular or oval depressions more than 1 km (0.6 mile) in diameter—have been formed by inward collapse of landforms after large amounts of magma have been expelled from underground.
What Causes a Volcano to Erupt? | Britannica
Volcanic eruptions are among the most stunning phenomena in the natural world. Volcanoes erupt because of the way heat moves beneath Earth ’s surface. Heat is conveyed from the planet’s interior to its surface largely by convection —the …