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Volcano - Wikipedia


A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava ... Erupting volcanoes can pose many hazards, not only in the immediate vicinity of the eruption. ...

What causes a volcano erupt?


A volcano begins as melted rock (magma) which rises from deep inside the earth toward the surface. As the gas-filled magma rises ...

Why are there volcanoes? Why do they erupt? | Volcano World ...


Volcanoes erupt because of density and pressure. The lower density of the magma relative to the surrounding rocks causes it to rise (like air bubbles in syrup).

How Do Scientists Know a Volcano Is About to Erupt? - Live Science


Oct 25, 2010 ... Mount Merapi is expected to erupt at any moment, and Indonesian officials ... " Rising magma causes solid rock to break, sending earthquake ...

What causes Volcanoes? - Geoscience Australia


Volcanic activity frequently occurs at the boundaries of the Earth's tectonic plates ... An eruption can be preceded by hundreds of small earthquakes know as ...

Just Ask: What Makes Volcanoes Erupt? | PBS NewsHour


Nov 30, 2010 ... It's time for our weekly Just Ask feature, where the experts tackle your questions on science and technology. John Eichelberger, a volcano ...

What makes a volcano erupt? | Reference.com


Volcanoes erupt due to pressure that the weight of the rocks puts on the magma and forces it to the surface out any available vent or exit provided to it.

Volcanoes - Weather Wiz Kids weather information for kids


Eruptions can cause lateral blasts, lava flows, hot ash flows, mudslides, avalanches, falling ash and floods. Volcano eruptions have been known to knock down ...

Volcanoes and volcanic eruptions - BBC


A secondary school revision resource for GCSE Geography covering key facts about volcanoes and volcanic eruptions.

Volcanic Eruptions | Scholastic.com


How many volcanoes erupt every day? ... How does a volcano build up the pressure to erupt? The magma ... How can you tell if a volcanic eruption might occur?

More Info

What causes a volcano to erupt and how do scientists predict ...


When a part of the earth's upper mantle or lower crust melts, magma forms. A volcano is essentially an opening or a vent through which this magma and the ...

What Causes A Volcanic Eruption? | IFLScience


Jan 6, 2016 ... What causes the world's explosive volcanic eruptions, like the 1980s ... gas bubbles form from the magma in a process known as vesiculation, ...

How It Happens | Volcanic Eruptions - Video - NYTimes.com


Jan 5, 2015 ... The eruption of a volcano can be one of the planet's most destructive events — spewing huge amounts of rock, gas and ash that can kill people.