Volcanoes

A:

An active volcano is one that has had at least one eruption in the past 10,000 years. An active volcano can be dormant or erupting.

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 country has the most active volcanoes?

    Q: What country has the most active volcanoes?

    A: Indonesia has 147 volcanoes, 76 of which are still active making it the world's most active volcano country. The country consists of a chain of more than 13,000 islands that are spread out over an area similar in size to the continental United States.
    See Full Answer
    Filed Under:
  • What is the oldest volcano in the world?

    Q: What is the oldest volcano in the world?

    A: Mt. Etna is considered the oldest volcano in the world. Its first recorded eruption took place around 1500 B.C.E. Since that date, the volcano is believed to have erupted an additional 190 times.
    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 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 country has the most volcanoes?

    Q: What country has the most volcanoes?

    A: Indonesia has the most volcanoes, with 76 volcanoes that have erupted within historical times. The Smithsonian Institution has 141 Indonesian entries in its volcano database; this includes volcanoes which have yet to erupt.
    See Full Answer
    Filed Under:
  • How do volcanoes affect the environment?

    Q: How do volcanoes affect the environment?

    A: An erupting volcano emits gases and dust particles that can cause profound changes in weather and climate throughout the world. Volcanism also affects the environment by producing acid rain and making ocean water warmer.
    See Full Answer
    Filed Under:
  • Where is Krakatoa located?

    Q: Where is Krakatoa located?

    A: Krakatoa is a volcanic island located in the Sunda Strait between Java and Sumatra in Indonesia. The island measures 3 miles wide by 5 1/2 miles long.
    See Full Answer
    Filed Under:
  • What is an active volcano?

    Q: What is an active volcano?

    A: An active volcano is one that has had at least one eruption in the past 10,000 years. An active volcano can be dormant or erupting.
    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:
  • 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:
  • When did Mount Saint Helens erupt?

    Q: When did Mount Saint Helens erupt?

    A: Mount St. Helens' most significant eruption in modern times occurred on March 20, 1980. It was followed by additional eruptions between Dec. 7, 1989 to Jan. 6, 1990, Nov. 5, 1990 to Feb. 14, 1991, Oct.11, 2004, Mar. 8, 2005, and between Jan. 16, 2008 to July 10, 2008.
    See Full Answer
    Filed Under:
  • What is the top of a volcano called?

    Q: What is the top of a volcano called?

    A: The top of a volcano is called the crater. A volcano is shaped like an inverted cone, and the tip of the cone is the crater. The crater is the opening of the vent in a volcano through which the molten magma or the lava is ejected.
    See Full Answer
    Filed Under:
  • What is an ash cloud?

    Q: What is an ash cloud?

    A: An ash cloud is a large cloud of smoke and debris that forms over a volcano after it erupts. Ash clouds consist of several elements, including ash, gases, dust, steam, rock fragments and other materials that come from inside the volcano and combine in the air above the crater.
    See Full Answer
    Filed Under:
  • How does a volcano form?

    Q: How does a volcano form?

    A: A volcano forms when a vent in the Earth's crust allows magma to well up from below. The magma fills a void underneath the surface, and when it builds up enough pressure, it bursts through to the surface. As the magma cools, it hardens into rock, and multiple eruptions may build up the mountainous form of a volcano.
    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: The negative effects of volcanoes include the destruction of man-made and natural environments and the death of human, animal and plant life. On the other hand, volcanoes generate geothermal energy and produce nutrients that result in fertile soil.
    See Full Answer
    Filed Under:
  • How are inselbergs formed?

    Q: How are inselbergs formed?

    A: Inselbergs, or isolated rock hills or mountains, are formed by erosion and long-term weathering. A type of disintegration landform, inselbergs are steep sided and rise abruptly from a gently sloping terrain or level surrounding plain. Their formation may be initiated by a volcanic process that causes a body of relatively erosion-resistant hard rock inside a body of softer rock to rise, which eventually erodes to expose the inner hard-rock portion.
    See Full Answer
    Filed Under:
  • What are the names of some dormant volcanoes?

    Q: What are the names of some dormant volcanoes?

    A: Mount Fuji and Mount Ranier are both names of dormant volcanoes. Dormant volcanoes are those that have not recently erupted but are still expected to at some point in time.
    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 causes a volcano to erupt?

    Q: What causes a volcano to erupt?

    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:
  • 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: