Earthquakes 101 | National Geographic

00:05:01
https://www.youtube.com/watch?v=_r_nFT2m-Vg

الملخص

TLDRThe video provides an overview of earthquakes, detailing their causes, predominant regions, and measurement techniques. It explains that earthquakes are primarily linked to the movement of tectonic plates, with significant occurrences in areas like the circum-pacific belt. It mentions the moment magnitude scale as a preferred method for measuring earthquakes and highlights the historical Valdivia earthquake of 1960 as the most powerful recorded. Lastly, the video underscores adaptation strategies adopted by communities to mitigate damage from earthquakes.

الوجبات الجاهزة

  • 🌍 Earthquakes are prominent in specific regions around the world.
  • ⚡ Pressure from tectonic plate movement causes earthquakes.
  • 📏 The moment magnitude scale is preferred for measuring quakes.
  • 🌊 The 1960 Valdivia earthquake generated a devastating tsunami.
  • 🏗️ Communities design earthquake-resistant buildings.
  • 🔍 Seismographs record seismic activities through oscillation lines.

الجدول الزمني

  • 00:00:00 - 00:05:01

    The video discusses the occurrence of earthquakes around the world, highlighting that while they are recorded on all continents, most happen in three main regions: the mid-atlantic ridge, the alpide belt, and the circum-pacific belt. Earthquakes are primarily caused by stress in the Earth's crust due to the movement of tectonic plates, which can become stuck and accumulate pressure, eventually leading to a release of energy that results in seismic activity. Seismographs are used to record these events, measuring their strength primarily via the moment magnitude scale, which is logarithmic and does not have an upper limit. The video also mentions the 1960 Valdivia earthquake in Chile, the most powerful recorded, and discusses how communities in earthquake-prone areas implement protective measures to mitigate damage and educate the public. Despite their destructive nature, earthquakes also contribute to the geological diversity of the planet.

الخريطة الذهنية

فيديو أسئلة وأجوبة

  • What causes earthquakes?

    Earthquakes are caused by pressure from stress in the Earth's crust, primarily due to the movement of tectonic plates.

  • Where do most earthquakes occur?

    Most earthquakes occur in three main regions: the mid-atlantic ridge, the alpide belt, and the circum-pacific belt.

  • How are earthquakes measured?

    Earthquakes are measured using seismographs, and the moment magnitude scale is preferred for its ability to measure high magnitudes globally.

  • What was the largest recorded earthquake?

    The largest recorded earthquake was the Valdivia earthquake in 1960, measuring about 9.5 in magnitude.

  • How do communities prepare for earthquakes?

    Communities prepare by designing buildings to sway rather than break and conducting public education and drills.

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الترجمات
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التمرير التلقائي:
  • 00:00:00
    [Music]
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    from above the planet appears eerily
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    still but every mountain range and every
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    chasm on its face is a scar with many
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    telling a story of when the earth
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    rumbled to life earthquakes occur around
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    the world they've been recorded on all
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    seven continents but most quakes take
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    place in just three regions the
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    mid-atlantic ridge an underwater line
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    that runs down the Atlantic Ocean the
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    alpide belt which stretches from the
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    Mediterranean to Southeast Asia and the
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    circum-pacific belt which traces along
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    the edges of the Pacific Ocean and is
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    where about 80% of all earthquakes occur
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    these areas experience the most
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    earthquakes due to what lies beneath the
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    surface
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    earthquakes are the result of pressure
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    specifically pressure caused by extreme
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    stress in the Earth's crust that stress
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    can be caused by volcanic activity or
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    even man-made activities in certain
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    areas
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    however most earthquake inducing stress
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    is caused by the movement of tectonic
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    plates tectonic plates are constantly
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    moving either against away along or
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    underneath each other but sometimes
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    their edges may catch and stick the
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    plates however continue to move or at
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    least attempt to energy from this
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    attempted movement fields around the
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    edges sticking point creating immense
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    pressure until the edges are forced to
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    let go and the plates slip this causes a
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    sudden and powerful release of energy so
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    powerful that it breaks the Earth's
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    crust this fracturing emits shockwaves
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    through the ground and causes intense
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    vibrations or quakes in fact the world's
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    most earthquake-prone regions are where
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    the most geologically active plates meet
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    [Music]
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    earthquakes or any seismic activity are
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    recorded by seismographs when the ground
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    shakes seismographs oscillate drawing a
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    jagged line to reflect this movement the
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    more extreme the earthquake the greater
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    the height of the jagged line these
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    recorded motions are then used to
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    measure the earthquake strength or
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    magnitude while several scales of
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    magnitude exist the one seismologist
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    prefer is the moment magnitude scale it
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    has no upper limit and it measures
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    earthquakes logarithmic ly this means
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    that each magnitude on its scale is ten
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    times greater than the one before it
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    unlike the now rarely used Richter scale
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    the moment magnitude scale can be
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    applied globally and can measure quakes
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    of the highest magnitudes the largest
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    recorded earthquake occurred near
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    Bolivia Chile in 1960 nestled within the
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    circum-pacific belt the Valdivia
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    earthquake was the most powerful in a
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    series of quakes that struck the region
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    measuring at a magnitude of about 9.5 in
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    addition to causing devastating tremors
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    on land the earthquake also generated a
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    deadly tsunami reaching up to 80 feet
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    high the tsunami raced across the
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    Pacific Ocean
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    hitting faraway countries like the
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    Philippines and Japan in fact data from
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    seismographs showed that the shock waves
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    emitted by the Valdivia earthquake
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    continued to shake the entire planet for
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    days some earthquake prone areas have
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    adapted various ways to protect their
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    communities buildings and bridges are
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    designed to sway rather than break when
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    an earthquake occurs the public is
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    educated on how to protect themselves
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    during a seismic event and government
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    officials enact drills to ensure the
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    protection of their people earthquakes
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    can leave behind incredible devastation
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    but these same forces have also created
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    magnificent features with each adding
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    character to a planet so unique
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    [Music]
الوسوم
  • earthquakes
  • seismology
  • tectonic plates
  • moment magnitude scale
  • Valdivia earthquake
  • circum-pacific belt
  • earthquake preparedness
  • seismographs
  • tsunami
  • geological activity