The location below the earths surface where the earthquake starts is called the hypocenter, and the location directly above it on the surface of the earth is called the epicenter. They can pass through solids, liquids and gases easily. This animation produced in conjunction with kqeds quest series, walks viewers through an easy to understand, playful introduction to earthquake basics and various different seismic waves. Such waves correspond to ripples of water that travel across a lake. Normal fault animation k blind thrust fault animation k. Animations of seismic ray propagation and phase recordings from. Seismic waves earthquakes discovering geology british. By studying the animation and the paper model, students will come to understand that. One, because theyre interesting by themselves, but theyre also really useful for figuring out what the actual composition of the earth is. Three seismic waves the energy of all three types of waves is passed from one rock particle to another in the same way one domino hits another and then another in a line of falling dominoes. Science briefs about new earthquake research written for nonscientists. Search, discover and share your favorite earthquake gifs. The report is intended to help students and others visualize what causes earthquake shaking and some of the possible results of the shaking. Usgs resources and links to outside educational resources.
Primary waves or p waves are the fastest moving waves, traveling at 1 to 5 miles per second 1. Software to download usgs earthquake hazard program. The destructive power of hurricanes, typhoons and cyclones. The animations below illustrate both the propogation of the wave as well as the motion of particles as the wave passes. These seismic waves cause backandforth, sidetoside, and upanddown motions in the earth. This article is about waves that travel through the earth. P waves, also called compressional waves or primary waves, move through material by squeezing and stretching the material in the same direction as the wave is moving. A seismogram is the graph output from a seismograph, which is used to determine the epicenter of an earthquake. Seismic wave animations for the p, s, rayleigh and love waves have been created using a 3d grid shown in figure 1. The following animation helps to understand the motion of each type of wave. Earthquakes can range in size from those that are so weak that they cannot be felt to those violent enough to toss people around and destroy whole cities. Seismic wave motions4 waves animated incorporated research. Fun and educational resources including science fair ideas and earthquake science you can understand.
The third general type of earthquake wave is called a surface wave, reason being is that its motion is restricted to near the ground surface. As a p wave travels, the green dots vibrate back and forth a parallel or b perpendicular to the direction of wave travel. Earthquakes shake the ground because fault rupture releases vibrations that radiate in the form of seismic energy. Seismic waves are fundamentally of two types, compressional, longitudinal waves or shear, transverse waves. Seismic waves is a browserbased tool to visualize the propagation of seismic waves from historic earthquakes through earths interior and around its surface. Locating earthquakes, datalogging and software once we know the distance to an earthquake from three seismic stations, we can determine the location of the earthquake. This model shows how forces, faults, and friction interact as elastic energy is slowly stored when the rubber back stretches and then is rapidly released as the block jerks during an earthquake. How they are formed and what happens during an eruption. The lines represent pwaves radiating out from the earthquake. All wave types are designed to propagate in the x direction illustrated in figure 1 and parallel to the earths surface. By carefully examining these seismic wave fronts and their propagation, the seismic waves tool illustrates how earthquakes can provide evidence that allows us. For each spherical harmonic degree l and azimuthal order number m, the l,m response function is deternined subject to jumps in.
Easytouse controls speedup, slowdown, or reverse the wave propagation. Use the movie controls to examine the motion of the waves. Chapter 2 section 2 earthquakes and seismic waves quizlet. These earthquake waves, also called body waves, come in two distinct forms. Hash is a fortran 77 code that computes doublecouple earthquake focal mechanisms from p wave first motion polarity observations, and optionally sp amplitude ratios. Animation of the singleblock earthquake machine, a mechanical model of the earthquake process using a wood block, sandpaper, and rubber bands. What i want to do in this video is talk a little bit about seismic waves. A longitudinal p wave has the ability to move through solid rock and fluid rock.
The compressional waves are the first to reach the earthquake recording station as they travel 1. The tectonic plates divide the earths crust into distinct plates that are always slowly moving. Earthquake body waves are divided into two types called primary p waves and secondary s waves. These motions are what people sense during a earthquake. Waves of energy that travel through the earths layers, and are a result of earthquakes, volcanic eruptions, magma movement, large landslides and large manmade explosions. Maple programming help maplesoft software for mathematics. Seed was designed for use by the earthquake research community, primarily for the exchange between institutions of unprocessed earth motion data.
Primary and secondary waves are known as body waves, and these waves penetrate the interior of the earth, whereas surface waves do not penetrate the earth. We focus on building operational software that allows us to account for complex eew scenarios while at the same time making warnings faster and more accurate see below. Earthguide online classroom types of earthquake waves. A type of seismic wave that moves the ground up and down or side to side. Which type of earthquake wave is a compressional wave. Seismic waves radiate outward from an earthquakes epicenter like ripples on water. Through the body of the earth these are called pwaves for primary because they are fastest and swaves for secondary since they are slower. How earthquakes at sea can trigger devastating waves. Besides the rupturemodeling software, a numerical method and the corresponding code for computing the seismic waves excited by the rupture is needed. Seismic waves can cause earthquakes and have destructive capability. Seen from this vantage point, theres a certain beauty to mother nature in action.
Waveform data formats seed standard for the exchange of earthquake data format. Animations were generated using a combination of the gmt, imagemagick, and povray software packages. The wave front is the instantaneous boundary between the seismic waves in the earth material, and the material that the seismic energy has not yet reached. Why does the earth shake when there is an earthquake. See at a glance up to seven days of global earthquake activity with this desktop earthquake monitor. An earthquake is what happens when two blocks of the earth suddenly slip past one another. Among the many types of seismic waves, one can make a broad distinction between body waves, which travel through the earth, and surface waves, which travel at the earths surface 4850.
An earthquake generates a series of seismic waves that travel through the interior or near the surface of the earth. S waves, also called shear waves or secondary waves, move materials at right angles to the wave direction. The faster of these body waves is called the primary or p wave. Seismic waves are fundamentally of two types, compressional, longitudinal waves or shear. Each wave has a characteristic speed and style of motion. Waves rippling across the pacific, as if a stone were thrown into a calm pond. Initially, two types of waves radiate from the focus. Primary waves or pwaves these are compressional waves, also known as longitudinal waves and are the first seismic waves to arrive at a location on the earth. The point beneath the earths surface where rock breaks under stress and causes an earthquake. The farther away an earthquake is, the greater the time between the arrival of the p waves and the s waves.
Video of the shifting rock in an earthquake causes vibrations called seismic waves that travel within earth or along its surface. Animated guides to the worlds most devastating phenomena. The shadow zone results from s waves not shown in animation being stopped entirely by the liquid core and p waves being bent refracted by the liquid core. Chilean earthquake waves in animation open culture. Flash was acquired by macromedia from futurewave software. A tsunami forms when energy from an earthquake vertically jolts the seabed by several metres, displacing hundreds of cubic kilometres of water. Earthquake shaking and damage is the result of three basic types of elastic waves. The wave animations illustrate wave characteristics and particle motion as listed in table 1. The p wave, also called the primary wave, is the fastest seismic wave.
Locating earthquakes earthquakes british geological. The different colors of the lines represent the velocity of the waves. Analysis of the earths internal structure is made possible. Large waves begin moving through the ocean, away from the earthquake s epicentre. However, where a free surface is present like the earthair interface these two types of. When body waves reach the free surface of the earth some of their energy is converted into complex surface waves that are trapped near the surface of the earth and produce generally lower frequency ground motions. Sep 08, 2008 animated guides to the worlds most devastating phenomena. An earthquake generates seismic waves that penetrate the earth as body. Earthquakes are concentrated along these plate boundaries. Draw a circle around each station with a radius equal to its distance from the earthquake. Seed is an international standard format for the exchange of digital seismological data.
When the plates fracture or slip, energy is released as seismic waves source. The different wave types have different travel velocities and modes of vibration. This poster combines a visualization of ground motion resulting from the february 21, 2008 m 6. This simulation shows the motion of p and s waves generated by a single earthquake. Its motion is the same as that of a sound wave in that, as it spreads out, it alternately pushes compresses and pulls dilates the rock. Youve seen my video on the actual layers of the earth, and seismic waves are crucial to actually realizing how people figured out. Earthquake early warning research at the sed the sed is involved in developing and testing different eew algorithms in switzerland and around the world. Seismic waves radiate outward from an earthquake s epicenter like ripples on water. This report illustrates, by means of a computer animation, how an earthquake occurs and what types of damage may result. Both p and s waves penetrate the interior of the earth while surface waves do not. Codes for earthquake rupture and groundmotion simulation cers have software packages as listed below.
Seismic wave demonstrations and animations purdue university. The animations below illustrate both the propogation of the wave as well as the. For ocean waves sometimes called seismic sea waves, see tsunami. The field also includes studies of earthquake environmental effects such as tsunamis as well as diverse. P waves, also called compressional waves or primary waves, move through material by squeezing and stretching the material in the same direction as the wave.
Seismic waves viewer incorporated research institutions. Visualizing seismic waves for teaching and research. A longitudinal p wave has the ability to move through solid rock and fluid rock, like water or the semiliquid layers of the earth. Examine p and s waves moving through earths interior. When body waves reach the free surface of the earth some of their energy is converted into complex surface waves that are trapped near the. Data analysis and seismogram interpretation gfzpublic. The shadow zone is the area of the earth from angular distances of 104 to 140 degrees that, for a given earthquake, that does not receive any direct p waves. Surface waves in earthquakes can be divided into two types. Zoom and spin your way around the globe while viewing earthquakes in three dimensions. Mercalli scale a scale that rates earthquakes according to their intensity and how much damage they cause at a particular place.
It pushes and pulls the rock it moves through in the same way sound waves push and pull the air. Some of the wave energy reflects off the boundary between the mantle and core. When consulting the seismogram, pwaves always appear before swaves, as they travel faster and can travel through three states of matter as opposed to one. Ray paths and wavefronts were drawn using the taup toolkit.
Types of seismic waves and how they are recorded britannica. Body waves a body wave is a seismic wave that moves through the interior of the earth, as opposed to surface waves that travel near the earths surface. When an earthquake hits, the first thing you feel is the primary wave p wave. How and why the earth moves and different types of quake. As they travel through rock, the waves move tiny rock particles back and forth pushing them apart and then back together in line with the direction the wave is traveling. When an earthquake hits, the first thing you feel is the primary wave. Hash is designed to produce stable highquality focal mechanisms, and tests the solution sensitivity to possible errors in the firstmotion input and the computed takeoff angles. This animation is a way to visualize an earthquake as it travels outwards from its starting point through the earth viewed from above at left. The point on earths surface directly above an earthquakes focus.
P primary waves, s secondary waves and surface waves, which arrive at seismic recording stations one after another. Both are known as body waves, because they move through earths interior. An earthquake is the shaking of the surface of the earth, resulting from the sudden release of energy in the earths lithosphere that creates seismic waves. The seismic waves in this animation were computed using a grid of more than 100,000 synthetic seismograms computed across a grid of mantle locations for a 600kmdeep earthquake. A type of seismic wave that forms when p and s waves reach earths. Hash is a fortran 77 code that computes doublecouple earthquake focal mechanisms from pwave first motion polarity observations, and optionally sp amplitude ratios. The three types of seismic waves are primary waves, secondary waves and surface waves. They solve the seismic wave equation in a spherically layered isotropic medium using a decomposition into spheroidal and toroidal motions. If you download any of these animations you implicitly agree to give proper credit to the authors. Large waves begin moving through the ocean, away from the earthquakes epicentre. This animated footage gives you a more global view of the chilean earthquake in action.