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  1. Earthquakes do occur in Antarctica, but not very often. There have been some big earthquakes--including one magnitude 8.1 --in the Balleny Islands (between Antarctica and New Zealand). The boundary between the Scotia Plate and the Antarctic Plate just grazes the north tip of the Antarctic Peninsula (look "northwest" from the Pole toward South ...

    • Overview
    • Causes of earthquakes

    Over the centuries, earthquakes have been responsible for millions of deaths and an incalculable amount of damage to property. Depending on their intensity, earthquakes (specifically, the degree to which they cause the ground’s surface to shake) can topple buildings and bridges, rupture gas pipelines and other infrastructure, and trigger landslides, tsunamis, and volcanoes.  These phenomena are primarily responsible for deaths and injuries. Very great earthquakes occur on average about once per year.

    What are earthquake waves?

    Earthquake waves, more commonly known as seismic waves, are vibrations generated by an earthquake and propagated within Earth or along its surface. There are four principal types of elastic waves: two, primary and secondary waves, travel within Earth, whereas the other two, Rayleigh and Love waves, called surface waves, travel along its surface. In addition, seismic waves can be produced artificially by explosions.

    How is earthquake magnitude measured?

    Magnitude is a measure of the amplitude (height) of the seismic waves an earthquake’s source produces as recorded by seismographs. Seismologist Charles F. Richter created an earthquake magnitude scale using the logarithm of the largest seismic wave’s amplitude to base 10. Richter’s scale was originally for measuring the magnitude of earthquakes from magnitudes 3 to 7, limiting its usefulness. Today the moment magnitude scale, a closer measure of an earthquake’s total energy release, is preferred.

    Where do earthquakes occur?

    Earth’s major earthquakes occur mainly in belts coinciding with the margins of tectonic plates. This has long been apparent from early catalogs of felt earthquakes and is even more readily discernible in modern seismicity maps, which show instrumentally determined epicentres. The most important earthquake belt is the Circum-Pacific Belt, which affects many populated coastal regions around the Pacific Ocean—for example, those of New Zealand, New Guinea, Japan, the Aleutian Islands, Alaska, and the western coasts of North and South America. It is estimated that 80 percent of the energy presently released in earthquakes comes from those whose epicentres are in this belt. The seismic activity is by no means uniform throughout the belt, and there are a number of branches at various points. Because at many places the Circum-Pacific Belt is associated with volcanic activity, it has been popularly dubbed the “Pacific Ring of Fire.”

    Britannica Quiz

    April Showers to March’s Lions and Lambs

    A second belt, known as the Alpide Belt, passes through the Mediterranean region eastward through Asia and joins the Circum-Pacific Belt in the East Indies. The energy released in earthquakes from this belt is about 15 percent of the world total. There also are striking connected belts of seismic activity, mainly along oceanic ridges—including those in the Arctic Ocean, the Atlantic Ocean, and the western Indian Ocean—and along the rift valleys of East Africa. This global seismicity distribution is best understood in terms of its plate tectonic setting.

  2. Oct 18, 2022 · Earthquakes occur when vast amounts of energy are released from Earth 's crust in the form of seismic waves. The waves radiate outwards from the source of the stress, known as the hypocenter, and ...

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  4. Feb 6, 2023 · Most earthquakes occur at fault zones, where tectonic plates —giant rock slabs that make up Earth's upper layer—collide or slide against each other. These impacts are usually gradual and ...

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  5. en.wikipedia.org › wiki › EarthquakeEarthquake - Wikipedia

    An earthquake is the shaking of the surface of Earth resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes may also be referred to as quakes, tremors, or temblors. The word tremor is also used for non-earthquake seismic rumbling . In its most general sense, an earthquake is any seismic event ...

  6. A normal (dip-slip) fault is an inclined fracture where the rock mass above an inclined fault moves down (Public domain.) An earthquake is what happens when two blocks of the earth suddenly slip past one another. The surface where they slip is called the fault or fault plane. The location below the earth’s surface where the earthquake starts ...

  7. Let’s look at the mechanisms behind this. 1. The plates do not always move smoothly past each other at faults. 2. Sometimes plate edges get stuck because of friction but the rest of the plate keeps moving, very slowly. 3. The energy and pressure that move the plates get stored up at the edges. 4.

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