Section outline

  • General

    Collapse all Expand all

  • 地震震级

    Destruction from the 2010 Chile earthquake, showing a car crushed under rubble.

     

    How do scientists measure earthquakes?
    ::科学家如何测量地震?

    This 8.8 magnitude   in Chile in 2010 caused over 500 deaths and thousands of injuries. Earthquakes and the damage they cause can be measured in a few different ways. One way is to describe the damage. The other way is to measure the  energy  of the quake.
    ::2010年智利的8.8级地震造成500多人死亡,数千人受伤,地震及其造成的破坏可以用几种不同的方式衡量,一种是描述损害,另一种是测量地震的能量。

    Earthquake Intensity
    ::地震强度

    The ways seismologists measure an earthquake have changed over the decades. Initially, they could only measure what people felt and saw: the intensity. For this, they used the Mercalli scale.
    ::地震学家测量地震的方式在过去几十年中发生了变化。 最初,他们只能测量人们的感知和所见:强度。为此,他们使用了默卡利尺度。

    Mercalli Scale
    ::Mercalli 比例缩缩

    Early in the 20th century, earthquakes were described in terms of what people felt and the damage that was done to buildings. The  Mercalli intensity scale  describes earthquake intensity.
    ::20世纪初,人们用人们的感受和对建筑物的破坏来描述地震。 默卡利强度尺度描述地震强度。

    There are many problems with the Mercalli scale. The damage from an earthquake is affected by many things. The type of ground a building sits on is very important to what happens to that building in a quake. Different people experience an earthquake differently. Using this scale, comparisons between earthquakes were difficult to make. A new scale was needed.
    ::Mercalli 规模有许多问题。 地震的破坏会受到许多事情的影响。 建筑的地面类型对于地震中建筑物发生的情况非常重要。 不同的人经历地震的经历不同。 使用这个规模,很难对地震进行比较。 需要一个新的规模。

    Earthquake Magnitude
    ::地震磁度

    For decades scientists have had equipment that can measure earthquake magnitude. The earthquake magnitude is the energy released during the quake.
    ::数十年来,科学家们拥有测量地震规模的设备。 地震规模就是地震期间释放的能量。

    The Richter Magnitude Scale
    ::较富有的磁度缩放

    Charles Richter developed the  Richter magnitude scale  in 1935. The  Richter scale  measures the magnitude of an earthquake's largest jolt of energy. This is determined by using the height of the waves recorded on a  seismograph .
    ::查尔斯·里希特在1935年开发了里氏级。里氏级测量地震最大的能量震荡。这是用地震仪上记录的海浪高度决定的。

    The Richter scale is logarithmic. The magnitudes jump from one level to the next. The height of the largest wave increases 10 times with each level. So the height of the largest   of a magnitude 5 quake is 10 times that of a magnitude 4 quake. A magnitude 5 is 100 times that of a magnitude 3 quake. With each level, thirty times more energy is released. A difference of two levels on the Richter scale equals 900 times more released energy.
    ::Richter 规模是对数尺度。 大小从一个级别跳到另一个级别。 最大波的高度每层增加10倍。 因此, 5级地震中最大的高度是4级地震的10倍。 5级是3级地震的100倍。 每级释放的能量是30倍。 里氏级中两个等级的差异等于释放的能量的900倍。

    The Richter scale has limitations. A single sharp jolt measures higher on the Richter scale than a very long intense earthquake. Yet, this is misleading because the longer quake releases more energy. Earthquakes that release more energy are likely to do more damage. As a result, another scale was needed.
    ::里氏级具有局限性。 一次强震比一场长期的强烈地震更能测量里氏级。 然而,这具有误导性,因为更长时间的地震释放出更多的能量。 释放出更多能量的地震可能会造成更大的破坏。 因此,需要另一种规模。

    The Moment Magnitude Scale
    ::动作磁度缩放

    The  moment magnitude scale  is the favored method of measuring earthquake magnitudes. It measures the total energy released by an earthquake. Moment magnitude is calculated by two things. One is the length of the   break. The other is the distance the ground moves along the fault. Japan's Tōhoku earthquake in 2011 had a magnitude of 9.0 ( Figure   ).
    ::时间尺度是测量地震规模的优选方法。 它测量地震释放的总能量。 时间尺度由两件事计算。 一是断裂的长度。 另一是断层的距离。 2011年日本的天井地震规模为9. 0( 图 ) 。

    Aerial view of earthquake and tsunami damage in Japan, 2011, showing devastation.

     

    Earthquake and tsunami damage in Japan, 2011. The Tōhoku earthquake had a magnitude of 9.0.
    ::2011年日本地震和海啸破坏情况,

    Summary
    ::摘要

    • Mercalli intensity scale depends on many factors other than the amount of energy released in the earthquake. These factors include the type of rock in the region. They also include the quality of the structures built in the area.
      ::Mercalli强度尺度取决于地震所释放的能量以外的许多因素,其中包括该区域的岩石类型,也包括在该地区建造的结构的质量。
    • The Richter scale is a logarithmic scale that measures the largest jolt of energy released by an earthquake.
      ::Richter规模是一个对数规模,用来测量地震所释放的最大能量的振动。
    • The moment magnitude scale is a logarithmic scale that measures the total amount of energy released by an earthquake.
      ::时空规模是一个对数尺度,用来测量地震释放的能量总量。

    Review
    ::回顾

    1. Under what circumstances might the Mercalli intensity scale be useful today? Why was it replaced by the Richter and then the moment magnitude scales?
      ::Mercalli的强度尺度今天在什么情况下有用? 为什么它被里氏取代,然后是时态的尺度?
    1. Why do scientists prefer the moment magnitude scale to the Richter scale?
      ::为什么科学家更喜欢时空星级 而不是里氏级呢?
    1. In 2011 there was a 5.8 magnitude quake that struck Virginia and a 9.0 quake that struck Japan. How might a 5.8 quake rate on the Mercalli scale in Virginia? How might a 5.8 magnitude quake rate on the Mercalli scale in Japan?
      ::2011年,有5.8级地震袭击了弗吉尼亚州,9.0级地震袭击了日本。 弗吉尼亚州Mercalli规模的Mercalli规模的5.8级地震率如何? 日本Mercalli规模的5.8级地震率如何?

    Explore More
    ::探索更多

    Use the resource below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    1. What was the magnitude of the 2010 Haiti earthquake?
      ::2010年海地地震的规模有多大?
    1. What does magnitude mean?
      ::规模意味着什么?
    1. How much larger is each earthquake magnitude?
      ::每个地震规模有多大?
    1. What is the difference between two magnitudes?
      ::两个星级之间有什么区别?
    1. What was the largest earthquake ever measured?
      ::有史以来最大的地震量测到什么?