地震波
Section outline
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Are seismic waves like ocean waves?
::地震波像海浪吗?Yes, in some ways. Ocean waves travel at the interface between the sea surface and the atmosphere . They have all the features that all waves have. Some seismic waves also travel at an interface. Which ones?
::是的,在某些方面。海洋波浪在海面和大气之间的界面上移动。它们具有所有波的特征。有些地震波也在界面上移动。哪些?Seismic Waves
::地震波Seismic waves are the energy from . Seismic waves move outward in all directions away from their source . Each type of seismic wave travels at different speeds in different materials. All seismic waves travel through , but not all travel through liquid or gas. Geologists study seismic waves to learn about earthquakes and the Earth’s interior.
::地震波是来自地震的能量。地震波从源头向外向外向外移动。 每一种地震波以不同速度以不同材料运行。 所有地震波都通过,但并非全部通过液体或气体。 地质学家研究地震波以了解地震和地球内部。Wave Structure
::波动结构Seismic waves are just one type of wave. Sound and light also travel in waves. Every wave has a high point called a crest and a low point called a trough . The height of a wave from the center line to its crest is its amplitude . The horizontal distance between waves from crest to crest (or trough to trough) is its wavelength ( Figure ).
::地震波只是一种波。 声音和光也会在波中移动。 每波都有一个高点, 叫做山顶, 叫做海沟。 从中线到其顶峰的海浪高度是它的振幅。 从海峰到海脊( 或海脊到海脊)之间的水平距离是波长( 图示 ) 。The energy from earthquakes travels in waves, such as the one shown in this diagram.
::地震产生的能量在波浪中流动,如本图所示。Types of Seismic Waves
::地震波类型There are two major types of seismic waves. Body waves travel through the Earth’s interior. Surface waves travel along the ground surface. In an earthquake, body waves are responsible for the sharp jolts. Surface waves are responsible for the rolling motions that do most of the damage in an earthquake.
::地震波有两大类。 体波穿过地球内部。 地表波沿着地面移动。 在地震中,体波是震动的源头。 地面波是地震中造成震动的源头。 地面波是地震中造成大部分破坏的滚动动动因素。Body Waves
::身体波浪Primary waves (P-waves) and secondary waves (S-waves) are the two types of body waves ( Figure ). Body waves move at different speeds through different materials.
::第一波(P波)和第二波(S波)是两种类型的身体波(图)。P-waves are faster. They travel at about 6 to 7 kilometers (about 4 miles) per second. Primary waves are so named because they are the first waves to reach a seismometer . P-waves squeeze and release rocks as they travel. The material returns to its original size and shape after the P-wave goes by. For this reason, P-waves are not the most damaging earthquake waves. P-waves travel through solids, liquids, and gases.
::脉冲速度更快。 它们以每秒大约6至7公里( 约4英里) 的速度行走。 初波之所以如此命名, 是因为它们是到达地震计的第一波波。 P波挤压和释放岩石。 材料恢复到P波经过后原有的大小和形状。 因此, P波并不是破坏性最大的地震波。 P波通过固体、液体和气体流动。S-waves are slower than P-waves. They are the second waves to reach a seismometer. S-waves move up and down. They change the rock’s shape as they travel. S-waves are about half as fast as P-waves, at about 3.5 km (2 miles) per second. S-waves can only move through solids. This is because liquids and gases don’t resist changing shape.
::S-波比P-波慢,它们是到达地震计的第二波。S-波向上和向下移动。S-波随着移动而改变岩石的形状。S-波大约是P-波的一半,每秒大约3.5公里。S-波只能通过固体移动。这是因为液体和气体不会抵制改变形状。P-waves and S-waves are the two types of body waves.
::波浪和S波是两种身体波。Surface Waves
::水面波浪Love waves and Rayleigh waves are the two types of surface waves.
::爱浪和雷利海浪是两种地表海浪。Surface waves travel along the ground outward from an earthquake’s epicenter . Surface waves are the slowest of all seismic waves. They travel at 2.5 km (1.5 miles) per second. There are two types of surface waves. Love waves move side-to-side, much like a snake. Rayleigh waves produce a rolling motion as they move up and backward ( Figure ). Surface waves cause objects to fall and rise. They also cause objects to sway back and forth. These motions cause damage to rigid structures during an earthquake.
::地表波从地震中心沿地面向外移动。地表波是所有地震波中最慢的。 地表波以每秒2.5公里( 1.5英里) 的速度移动。 地表波有两种类型。 爱波在侧侧移动, 类似于蛇。 雷利海浪在向上和向后移动时会产生滚动( 图 ) 。 地表波导致物体下降和上升, 也使物体向回移动。 这些运动在地震期间对僵硬结构造成损害 。Summary
::摘要- Body waves travel through the body of a planet. Surface waves travel along the surface.
::体波穿过一个行星的身体 地表波沿着表面移动
- There are two types of body waves: P-waves travel fastest and through solids, liquids, and gases; S-waves only travel through solids.
::身体波有两种:P波速度最快,通过固体、液体和气体;S波只通过固体。
- Surface waves are the slowest, but they do the most damage in an earthquake.
::地表波是最慢的,但地震造成的破坏最大。
Review
::回顾- Draw a set of waves and label the parts: crest, trough, amplitude, wavelength.
::绘制一组波和标注部件: 顶部、 槽、 振幅、 波长 。
- Compare and contrast P-waves and S-waves.
::与P波和S波的对比和对比。
- Describe the motions of surface waves.
::描述表面波浪的移动
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。- What are body waves?
::什么是身体波浪?
- Which waves move the fastest?
::哪个海浪移动最快?
- What are the S-waves? Describe them.
::S波是什么?
- What happens to body waves as they move through the Earth?
::当身体波浪穿过地球时会怎样?
- What are the two types of surface waves?
::这两类地表波是什么?
- Describe how surface waves travel.
::描述地表波的移动情况。
- Body waves travel through the body of a planet. Surface waves travel along the surface.