Volcanoes

A:

A volcano erupts when the pressure of a subterranean pool of magma becomes great enough to crack the earth's crust. Whether the eruption results in a violent explosion or a slow seepage depends on several different factors, according to How Stuff Works.

See Full Answer
Filed Under:
  • What Is the Pacific Ring of Fire?

    Q: What Is the Pacific Ring of Fire?

    A: The Pacific Ring of Fire is the name for a horseshoe-shaped region of high seismic and volcanic activity surrounding the Pacific Ocean Basin. In addition to volcanoes, the area encompasses major fault zones. It spans 25,000 miles and touches a number of island chains, as well as four continents.
    See Full Answer
    Filed Under:
  • What Is a Main Vent in a Volcano?

    Q: What Is a Main Vent in a Volcano?

    A: The main vent of a volcano is the outlet chamber in the Earth's crust that allows hot magma to reach the surface. While secondary vents may form to alleviate the pressure caused by a magma chamber, the main vent is responsible for giving volcanoes their familiar cone shape.
    See Full Answer
    Filed Under:
  • What Conditions Make for a Violent Volcanic Eruption?

    Q: What Conditions Make for a Violent Volcanic Eruption?

    A: According to the Oregon State University Department of Geosciences, a volcanic eruption may become violent if pressure builds up inside the volcano for any reason. An explosive eruption is much more dangerous than a steady flow of magma and can spread ash and pyroclastic material over a wide area. The eruption of Mount Saint Helens in 1980 was a textbook example of a violent, explosive volcanic eruption.
    See Full Answer
    Filed Under:
  • How Was Mount Kilimanjaro Formed?

    Q: How Was Mount Kilimanjaro Formed?

    A: Mount Kilimanjaro is a stratovolcano that formed as the plates below it dropped and porous basalt rock magma erupted through the surface of the ocean. The magma and other debris formed layers with each eruption, eventually rising high enough to bring Mount Kilimanjaro to its height of 19,341 feet.
    See Full Answer
    Filed Under:
  • What Do Volcanologists Do?

    Q: What Do Volcanologists Do?

    A: Volcanologists study the processes of volcano formation and their eruptive activity. In addition to studying current volcanic activity, they also study the eruptions of volcanoes throughout history.
    See Full Answer
    Filed Under:
  • What Is the Closest Volcano to Denver, Colorado?

    Q: What Is the Closest Volcano to Denver, Colorado?

    A: There are no active volcanoes near Denver, Colorado. Nearby extinct volcanoes are located 2 hours from Denver in the Central Colorado volcanic field. These include the Grizzly Peak and Mount Aetna cauldrons and Bonanza and Marshall Creek calderas. The Central Colorado Volcanic Field is located in Park and Teller counties.
    See Full Answer
    Filed Under:
  • Are Volcanoes Mountains?

    Q: Are Volcanoes Mountains?

    A: While many volcanoes are mountains, it is possible for a volcano to erupt from a vent in any type of land form. Over time, volcanoes become mountains by depositing their discharge around them in ever-increasing layers. Not all mountains are volcanoes.
    See Full Answer
    Filed Under:
  • Can Lava Melt Concrete?

    Q: Can Lava Melt Concrete?

    A: Concrete is a composite material, so it has no single melting point of its own. Each of the different components of concrete, primarily sand, gravel and cement, has a melting point of its own. Rather than melt concrete, molten lava causes it to rapidly decompose.
    See Full Answer
    Filed Under:
  • What Causes Volcanic Eruptions?

    Q: What Causes Volcanic Eruptions?

    A: Volcanic eruptions occur when magma builds up beneath the Earth's crust and forces its way to the surface. Natural vents in the crust allow magma passage to the surface, and eruptions occur when the magma that forms is less dense than the material above it, causing it to flow upward. In some cases, this flow is slow and steady, but it can also be rapid and violent.
    See Full Answer
    Filed Under:
  • When Will Yellowstone Erupt?

    Q: When Will Yellowstone Erupt?

    A: Predicting when the next eruption will occur is difficult; however, the National Science Foundation estimates the next major eruption shouldn't happen for at least another one million years. The next eruption may dump several inches of ash over a large portion of the United States and could change Earth's climate.
    See Full Answer
    Filed Under:
  • What Are Some Examples of Extinct Volcanoes?

    Q: What Are Some Examples of Extinct Volcanoes?

    A: Some examples of extinct volcanoes include Aconcagua in Argentina, Mount Kenya in Kenya, Mount Ashitaka in Japan and Mount Buninyong in Australia. Extinct volcanoes have been inactive for a long period of time and are considered unlikely to erupt again.
    See Full Answer
    Filed Under:
  • What Is a Magma Chamber?

    Q: What Is a Magma Chamber?

    A: A magma chamber is a structure made up of solidified crystal mush and molten rock located below the surface of the Earth. When a magma chamber solidifies and cools, it is known as a pluton.
    See Full Answer
    Filed Under:
  • Why Are There Volcanoes?

    Q: Why Are There Volcanoes?

    A: Volcanic vents allow the Earth to release built up gases from the heat and pressure emanating from its core. Magma rises towards the surface, and as the pressure builds the magma seeks outlets through which to flow. The higher the pressure build-up, the greater the volcanic explosion.
    See Full Answer
    Filed Under:
  • What Damage Do Volcanoes Cause?

    Q: What Damage Do Volcanoes Cause?

    A: Volcanoes cause physical damage to structures and buildings, wildlife, local vegetation and the atmosphere, as well as posing health risks. Residences within the vicinity of a volcanic eruption often receive timely notice before an eruption occurs. This reduces the likelihood of danger to humans.
    See Full Answer
    Filed Under:
  • What Are the Different Parts of a Volcano?

    Q: What Are the Different Parts of a Volcano?

    A: The main parts of a volcano include the summit crater, the magma chamber, the central vent and the edifice. While volcanoes vary considerably in terms of size and shape, most land volcanoes have structural similarities.
    See Full Answer
    Filed Under:
  • How Many Super Volcanoes Are There in the World?

    Q: How Many Super Volcanoes Are There in the World?

    A: The Earth has approximately 20 known supervolcanoes, according to James Morgan, who write for the BBC News. What constitutes a "supervolcano" is not clearly defined, so the term is avoided in the literature, but it is often used in reference to two distinct phenomena.
    See Full Answer
    Filed Under:
  • What Are the Positive and Negative Effects of Volcanoes?

    Q: What Are the Positive and Negative Effects of Volcanoes?

    A: Volcanoes have the capacity to produce widespread destruction by covering cities and towns with ash and lava. However, volcanic eruptions also create islands, and the minerals in volcanic ash stimulate plant growth.
    See Full Answer
    Filed Under:
  • What Is an Extinct Volcano?

    Q: What Is an Extinct Volcano?

    A: An extinct volcano is one that has not erupted in at least 10,000 years and is not expected to erupt in the future, according to Oregon State University. There can be confusion between dormant and extinct volcanoes, but the difference between the two is that a dormant volcano may erupt even if it is in the distant future.
    See Full Answer
    Filed Under:
  • Where Is Mount Kilimanjaro Located?

    Q: Where Is Mount Kilimanjaro Located?

    A: Mount Kilimanjaro is located in Tanzania. It is a dormant volcano comprising three volcanic cones, and is the highest peak in Africa.
    See Full Answer
    Filed Under:
  • What Is a Mudflow on a Volcano Called?

    Q: What Is a Mudflow on a Volcano Called?

    A: Mudflow on a volcano is called lahar and is typically caused by heavy rains during or after volcanic eruptions. Lahars can also occur when nearby ice or snow melts, carrying ash and rock debris down a volcano's slopes.
    See Full Answer
    Filed Under:
  • What Is the Most Destructive Volcano in the World?

    Q: What Is the Most Destructive Volcano in the World?

    A: To humans, the most destructive volcano in the world is Mount Tambora in Indonesia. This volcano created the most powerful eruption in known history and killed 100,000 people along the way. Its eruption was 100 times more powerful than Vesuvius.
    See Full Answer
    Filed Under: