Which best describes a volcano?
A volcano is a hole in Earth’s surface through which magma (called lava when it reaches Earth’s surface), hot gases, ash, and rock fragments escape from deep inside the planet. The word volcano also is used to describe the cone of erupted material (lava and ash) that builds up around the opening.
Which words identify stages of volcanic activity?
Answer: Answer: Active, dormant and extract are the stages of volcanic activity. Volcano is a natural disasters and when the rocks of the mountain expel out in the form of molten lava, gases and heat due to the development pressure, it can called as volcanic explosion.
What event causes a volcanic eruption?
Volcanoes erupt when molten rock called magma rises to the surface. Magma is formed when the earth’s mantle melts. Melting may happen where tectonic plates are pulling apart or where one plate is pushed down under another. Magma is lighter than rock so rises towards the Earth’s surface.
What is the most dangerous part of a volcanic eruption?
The most dangerous part of a volcano is the actually gasses that they all give off with all the smoke and ash.
Does earthquake cause volcanic eruption?
Sometimes, yes. A few large regional earthquakes (greater than magnitude 6) are considered to be related to a subsequent eruption or to some type of unrest at a nearby volcano. However, volcanoes can only be triggered into eruption by nearby tectonic earthquakes if they are already poised to erupt.
Do tectonic plates cause volcanoes?
Most of the world’s volcanoes are found around the edges of tectonic plates, both on land and in the oceans. On land, volcanoes form when one tectonic plate moves under another. When enough magma builds up in the magma chamber, it forces its way up to the surface and erupts, often causing volcanic eruptions.
Why was Wegener’s theory accepted?
The main reason that Wegener’s hypothesis was not accepted was because he suggested no mechanism for moving the continents. He thought the force of Earth’s spin was sufficient to cause continents to move, but geologists knew that rocks are too strong for this to be true.