What Are Volcanoes and How Are They Formed?

00:06:53
https://www.youtube.com/watch?v=R_pDKyg5YKY

Zusammenfassung

TLDRThe video explains the phenomenon of volcanic eruptions, detailing the processes beneath the Earth's crust and the relationship with tectonic plates. It highlights the locations of active volcanoes, particularly along tectonic plate boundaries, and introduces the concept of hot spot volcanoes. The different types of volcanoes are outlined, including composite and shield volcanoes, emphasizing their structures and eruptive behaviors. The video concludes by illustrating how volcanoes are indicators of dynamic geological processes beneath the surface of the Earth.

Mitbringsel

  • 🌋 There are over 600 active volcanoes on Earth.
  • 🌍 90% of the most powerful eruptions occur in the Pacific Ring of Fire.
  • 🧱 Composite volcanoes have a conical shape and are mostly found on destructive plate margins.
  • 🌀 Shield volcanoes have gentle slopes and are typically less violent.
  • ✨ Hot spot volcanoes form away from tectonic boundaries, like the Hawaiian Islands.
  • 💨 Eruptions can eject lava, volcanic bombs, ash, and gas.
  • 📉 The lithosphere is broken into tectonic plates that move like puzzle pieces.

Zeitleiste

  • 00:00:00 - 00:06:53

    The video discusses the phenomenon of volcanic eruptions, highlighting their destructive power and prevalence around the world. It mentions that there are over 600 active volcanoes with around 50 eruptions annually, while also referencing the existence of dormant and extinct volcanoes. The narrator explains that a volcano is a rupture in the Earth's crust and introduces key concepts about the lithosphere and tectonic plates, which play a crucial role in volcanic activity.

Mind Map

Video-Fragen und Antworten

  • What is a volcano?

    A volcano is a rupture in the Earth's crust that allows gas and molten rock to escape from inside the planet.

  • Where are most volcanoes located?

    Most volcanoes are found along tectonic plate margins.

  • What is the Ring of Fire?

    The Ring of Fire is a region where 75% of the world's active volcanoes are located, surrounding the Pacific Plate.

  • What are hot spot volcanoes?

    Hot spot volcanoes form away from tectonic plate boundaries when rising magma melts through the plate above, like the Hawaiian Islands.

  • What are the two main types of volcanoes?

    The two main types of volcanoes are composite volcanoes and shield volcanoes.

  • What materials are ejected during a volcanic eruption?

    Materials ejected include lava, volcanic bombs, ash, and gas.

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Untertitel
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Automatisches Blättern:
  • 00:00:05
    dramatic volcanic eruptions happen
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    all around the world humans are left in
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    both
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    fear and awe of these fiery powerful and
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    highly dangerous events
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    today there are over 600 active
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    volcanoes on earth
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    with at least 50 eruptions occurring
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    each year
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    but did you know there are many other
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    volcanoes out there that are
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    extinct or dormant
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    what is going on under the surface to
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    cause such a destructive event
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    to answer this question we must first
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    understand what a volcano is
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    [Music]
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    a volcano is essentially a rupture in
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    the earth's crust
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    the earth's rocky outermost layer that
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    lies on top of its hotter
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    inner layers
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    the earth's crust and the upper mantle
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    form the lithosphere
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    the lithosphere is broken up into slabs
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    known as tectonic plates
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    and they fit together like puzzle pieces
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    to make up the surface of the earth
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    most volcanoes are found along these
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    tectonic plate margins
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    either at a destructive or constructive
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    plate margin
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    both of these margins allow gas and
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    molten rock to escape from inside the
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    planet to the surface
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    at a destructive or convergent plate
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    margin
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    an oceanic tectonic plate which is a
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    plate mostly covered by the sea
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    and a continental plate which is mostly
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    covered by land
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    move towards each other
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    the denser oceanic plate sinks under the
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    continental plate
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    melting down into the earth's mantle
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    [Music]
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    this melting releases gases that make
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    their way through the crust above
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    and erupt through the surface
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    at a constructive or divergent plate
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    margin
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    the two plates move apart really slowly
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    less than five centimeters per year but
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    over time
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    this allows extremely hot magma to rise
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    up from deep within the planet
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    magma rises and fills the gaps created
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    by the plates moving away from each
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    other
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    and eventually new crust is formed
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    magma at the margin can sometimes
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    explode through this new crust
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    creating a volcanic eruption
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    many of these constructive margins are
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    found under the ocean
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    if you map the locations of volcanoes
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    you'll see that 75 of the world's active
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    volcanoes are along the margin of the
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    pacific plate
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    volcanologists refer to this as the ring
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    of fire
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    since 1850 approximately 90 percent of
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    the 16 most powerful volcanic eruptions
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    on earth
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    have occurred within the pacific ring of
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    fire making it one of the most dangerous
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    places on earth
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    however there are places on earth where
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    a volcano can
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    form away from tectonic plate boundaries
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    we call these
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    hot spot volcanoes
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    they form when rising magma from deep
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    within the planet
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    melts through the tectonic plate above
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    and begins to build up
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    an example of this is the hawaiian
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    islands
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    which are all made of a mixture of
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    extinct and active volcanoes that have
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    broken through the middle of the pacific
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    plate
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    now that you know where volcanoes form
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    let's learn about their different types
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    there are two main types composite
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    volcanoes
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    and shield volcanoes
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    the majority of volcanoes are composite
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    volcanoes
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    these are commonly found on destructive
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    plate margins
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    and have a distinctive conical shape
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    let's slice a composite volcano in half
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    to learn more about it
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    at the bottom of a composite volcano
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    lies a magma chamber
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    which is like a hot bubbling furnace
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    magma enters the chamber from the
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    earth's mantle
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    and collects here until pressure builds
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    causing gases to expand
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    and water to become steam
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    eventually the pressure becomes so high
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    that an explosion
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    or volcanic eruption occurs
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    most of the magma moves through the main
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    vent and exits the volcano through the
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    crater
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    some magma also makes its way through
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    secondary events and out through
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    secondary cones
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    craters can eject four different types
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    of materials into the atmosphere
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    these include lava which is the name for
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    magma that has reached the surface of
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    the earth
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    pieces of rocks called volcanic bombs
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    thick ash and gas
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    with every eruption the lava that
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    travels out of the crater
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    cools and solidifies along with ash to
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    form
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    alternate layers of ash and lava
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    composite volcanoes are also known as
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    strata volcanoes
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    because strato means layers
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    shield volcanoes on the other hand are
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    usually found on constructive plate
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    margins or at hot spots
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    they have gentle sloping sides caused by
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    runny lava
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    flowing quicker and covering longer
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    distances before it solidifies
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    they usually erupt less violently as
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    compared to composite volcanoes
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    volcanoes reflect the movements of
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    earth's major tectonic plates
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    and are signs of activity occurring
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    under the earth's surface
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    this gives us evidence that the earth is
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    not just a static and rigid rock
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    but one full of dynamic and powerful
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    forces
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    you
Tags
  • volcano
  • eruption
  • tectonic plates
  • magma
  • Ring of Fire
  • composite volcano
  • shield volcano
  • hot spot
  • active volcano
  • geological activity