When the plate bends downward, some of the rocks in the plate break. The larger the earthquake, the bigger the waves. Mud and Adobe Houses during Earthquakes, 3. Commonly, seismic wave is composed of two major waves namely body waves and surface waves. Lost your password? It is here from Michoacn state, part way up the Pacific coast, all the way down to southernmost Oaxaca that bending earthquakes could occur. When P- and S-waves reach the surface of the Earth, most of their energy is reflected back. Peak amplitude (peak ground acceleration, PGA) is physically intuitive. That means the capital could see another large quake. You might think that a skyscraper would be more dangerous than a smaller office building, but in fact, the opposite is often true. Diego Melgar does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment. On August 14, 2021, a magnitude 7.2 earthquake struck the southwest region of Haiti and killed over 2,000 people. But when the flexing becomes too strong, it will splinter violently. Across 1. ground bending. Local uplifts of the ground and water waves moving upstream gave the illusion that the river was flowing upstream. It runs through . Ground shaking move buildings from side to side and up and down. This setup continues for about 125 miles or so. The motor that rotates the drum at constant speed forms the timer. There, beneath thousands of feet of water, we see high, narrow ridges and deep valleys that run lengthwise in a northwest-to-southeast direction. These findings are a step forward in understanding Mexicos complex geology. S-waves are slower than P-waves, and speeds are typically around 60% of that of P-waves in any given material. A .gov website belongs to an official government organization in the United States. P waves propagate through the Earth with a speed of about 15,000 miles per hour and are the first waves to cause vibration of a building. The path that a wave takes between the focus and the observation point is often drawn as a ray diagram. Lutheran World Relief in . More than 51,000 people died in Turkey and neighboring Syria in the 7.8-magnitude earthquake that struck southern . The first principal earthquake, M7.5, occurred at about 2:15 am (local time) in northeast Arkansas on December 16, 1811. Select a countryland IslandsAfghanistanAlbaniaAlgeriaAndorraAngolaAnguillaAntarcticaAntigua and BarbudaArgentinaArmeniaArubaAustraliaAustriaAzerbaijanBahamasBahrainBangladeshBarbadosBelarusBelauBelgiumBelizeBeninBermudaBhutanBoliviaBonaire, Saint Eustatius and SabaBosnia and HerzegovinaBotswanaBouvet IslandBrazilBritish Indian Ocean TerritoryBritish Virgin IslandsBruneiBulgariaBurkina FasoBurundiCambodiaCameroonCanadaCape VerdeCayman IslandsCentral African RepublicChadChileChinaChristmas IslandCocos (Keeling) IslandsColombiaComorosCongo (Brazzaville)Congo (Kinshasa)Cook IslandsCosta RicaCroatiaCubaCuraaoCyprusCzech RepublicDenmarkDjiboutiDominicaDominican RepublicEcuadorEgyptEl SalvadorEquatorial GuineaEritreaEstoniaEthiopiaFalkland IslandsFaroe IslandsFijiFinlandFranceFrench GuianaFrench PolynesiaFrench Southern TerritoriesGabonGambiaGeorgiaGermanyGhanaGibraltarGreeceGreenlandGrenadaGuadeloupeGuatemalaGuernseyGuineaGuinea-BissauGuyanaHaitiHeard Island and McDonald IslandsHondurasHong KongHungaryIcelandIndiaIndonesiaIranIraqIsle of ManIsraelItalyIvory CoastJamaicaJapanJerseyJordanKazakhstanKenyaKiribatiKuwaitKyrgyzstanLaosLatviaLebanonLesothoLiberiaLibyaLiechtensteinLithuaniaLuxembourgMacao S.A.R., ChinaMacedoniaMadagascarMalawiMalaysiaMaldivesMaliMaltaMarshall IslandsMartiniqueMauritaniaMauritiusMayotteMexicoMicronesiaMoldovaMonacoMongoliaMontenegroMontserratMoroccoMozambiqueMyanmarNamibiaNauruNepalNetherlandsNetherlands AntillesNew CaledoniaNew ZealandNicaraguaNigerNigeriaNiueNorfolk IslandNorth KoreaNorwayOmanPakistanPalestinian TerritoryPanamaPapua New GuineaParaguayPeruPhilippinesPitcairnPolandPortugalQatarRepublic of IrelandReunionRomaniaRussiaRwandaSo Tom and PrncipeSaint BarthlemySaint HelenaSaint Kitts and NevisSaint LuciaSaint Martin (Dutch part)Saint Martin (French part)Saint Pierre and MiquelonSaint Vincent and the GrenadinesSan MarinoSaudi ArabiaSenegalSerbiaSeychellesSierra LeoneSingaporeSlovakiaSloveniaSolomon IslandsSomaliaSouth AfricaSouth Georgia/Sandwich IslandsSouth KoreaSouth SudanSpainSri LankaSudanSurinameSvalbard and Jan MayenSwazilandSwedenSwitzerlandSyriaTaiwanTajikistanTanzaniaThailandTimor-LesteTogoTokelauTongaTrinidad and TobagoTunisiaTurkeyTurkmenistanTurks and Caicos IslandsTuvaluUgandaUkraineUnited Arab EmiratesUnited Kingdom (UK)United States (US)UruguayUzbekistanVanuatuVaticanVenezuelaVietnamWallis and FutunaWestern SaharaWestern SamoaYemenZambiaZimbabwe, By registering, you agree to the Terms of Service and Privacy Policy .*. An earthquake is a shaking of the ground caused by the sudden breaking and shifting of rock beneath the Earth's surface. <<069051B711A4B046AAC99523C7ADE6EA>]>> Surface waves decay more slowly with distance than body waves which travel in three dimensions. The closer you are to the epicenter, the stronger the shaking. Secondary waves (S-waves) are shear waves that are transverse in nature. An earthquake of the strength reported on Monday is capable of causing widespread and heavy damage in urban areas. Bending moment of piles on piled raft foundation subjected to ground deformation during earthquake in centrifuge model test Authors: Junji Hamada Takenaka Research & Development Institute. 0000007065 00000 n Now, as working seismologists, we have discovered that the 2017 earthquake, called Puebla-Morelos, was fundamentally unlike its 1985 predecessor. This kind of rare Mexican quake typically has a relatively lower magnitude than the more common Pacific coast variety. It moves the ground surface up A seismograph, which is also known as seismometer, is an instrument used to detect and record earthquakes. The mode 0S1 does not exist because it would require a change in the center of gravity, which would require an external force. Assistant Professor of Geophysics, University of Oregon, Professor, Universidad Nacional Autnoma de Mxico (UNAM). The New Madrid fault system was responsible for the 1811-12 New Madrid earthquakes, an intense intraplate earthquake series that began with an initial earthquake of moment magnitude 7.5-7.9 on December 16, 1811, and was followed by a moment magnitude 7.4 aftershock on the same day.. No damages but a seismic seiche propagating . That catastrophe marked an entire generation of Mexicans, including ourselves, back when we were just kids. But the tectonic plates bend, we learned, is only half of the story behind central Mexicos shaking. Oops! surface waves Grasp one of its legs while covering your head with your other arm. It is measured with a Richter Magnitude scale. If an earthquake lasts longer and its extent is high, this may cause health issues like heart issues, panic attacks, and depression in survivors. Earthquake swarms are a type of such sequence of earthquakes. It can result from an earthquake (or generally, a quake), volcanic eruption, magma movement, a large landslide, and a large man-made explosion that produces low-frequency acoustic energy. 50 30 The alignment between texture and plate is not perfect but theyre off angle by just 20 to 30 degrees. Subway tunnels in LA are also lined with 12-inch thick concrete walls capable of bearing additional stress caused by ground movement during an earthquake. It may be due to volcanic eruptions, tectonic plates moving, cave formation in a small area, or explosions. They were by far the largest east of the Rocky Mountains in the U.S. and Canada. endstream endobj 51 0 obj <> endobj 52 0 obj <> endobj 53 0 obj <>/ColorSpace<>/Font<>/ProcSet[/PDF/Text/ImageC]/ExtGState<>>> endobj 54 0 obj <> endobj 55 0 obj <> endobj 56 0 obj <> endobj 57 0 obj <> endobj 58 0 obj <> endobj 59 0 obj <>stream Earthquakes create distinct types of waves with different velocities. P-wavesare the fastest type of seismic wave. Think of a sturdy piece of wood. When an earthquake occurs, seismographs near the epicenter are able to record both P and S waves, but those at a greater distance no longer detect the high frequencies of the first S wave. The 2011 Tokohu earthquake is known as one of the most devastating in recent times. The drum, pen and chart paper constitute the recorder. At most subduction zones, after one tectonic plate slides beneath a neighboring plate, it continues on a diagonal downward dive and sinks deep into the Earths mantle. time, but today, digital instruments using modern computer technology are more And when they hit near Mexico City, as September 2017 demonstrated, the consequences can be devastating. A mild tremor preceding the violent shaking movement of an earthquake 6 down 2 Across 1. The meizoseismal area was characterized by general ground warping, ejections, fissuring, severe landslides, and caving of stream banks. Structures like dams, nuclear power stations, bridges, tunnels, pipelines, roads, etc., are at high risk of ground rupture. In California, the Pacific and North American plates creep past each other in opposite directions, about 1.5 inches per year. During the shaking, stresses are produced in the ground leading to ground rupture. An earthquake is the sudden shaking of the earth that releases the energy in the earth's lithosphere, causing the creation of seismic waves. These data are used for determining some large scale structures of the Earth interior. Seismologists, too, are still studying the September 19 earthquake, trying to better understand whats happening underneath Mexico City. (Note: During an earthquake, do not hide under the staircase because it is one of the weakest parts of the building.). Interference of Rayleigh waves results in spheroidal oscillation S while interference of Love waves gives toroidal oscillation T. The modes of oscillations are specified by three numbers, e.g., nSlm, where l is the angular order number (or spherical harmonic degree, see Spherical harmonics for more details). 0000004710 00000 n Because that is the assumed life of a building. Since shear waves cannot pass through liquids, this phenomenon was original evidence for the now well-established observation that the Earth has a liquid outer core, as demonstrated by Richard Dixon Oldham. Most of the uplift occurred during prehistoric earthquakes. Seismic wave propagation is a ground motion phenomenon that relates to the passage of body waves, including compression waves and shear waves, radially from the source of earthquake energy release (hypocenter) into the surrounding rock and soil medium. They travel more slowly than seismic body waves (P and S). 9 What I Need To Know After performing the activities, . Determine design bending moment at the base. In large earthquakes, surface waves can have an amplitude of several centimeters.[7]. Like a sheet of plywood, a tectonic plate is more resistant to pressure when bent against the grain. The propagation velocity of a seismic wave depends on density and elasticity of the medium as well as the type of wave. Body waves travel through the interior of the Earth. Now, as working seismologists, we have discovered that the 2017 earthquake, called Puebla-Morelos, was fundamentally unlike its 1985 predecessor. This article will discuss 9 effects of earthquake-like Ground Shaking, Liquefaction, Ground Rupture, Flood, Tsunami, etc. Under such circumstances, the bent plate can more easily snap and break from continued tectonic movement. As P-waves travel, the surrounding rock is repeatedly compressed and then stretched along direction of energy transmission. About 37 mi (60 km) long, it lies mainly along the western base of the hills on the east side of San Francisco Bay. This setup continues for about 125 miles (200 km) or so. Table of Contents: . Major earthquakes typically occur along the Pacific coast. Universidad Nacional Autnoma de Mxico (UNAM), magnitude 7.1 earthquake struck Mexico City, shook the capital city again on February 16, 2018, magnitude 8.1 earthquake that killed at least 10,000 people in and around Mexico City, it is bent across a large, continuous swath of central and southern Mexico, Global Multi-Resolution Topography Data Synthesis. Rocks crack and slip past each other causing seismic waves that make the surface of the earth vibrate. The bonding stone is found to be effective as in Jammu Kashmir earthquake of August 24, 1980. Nuttli also noted that about eighteen hundred earthquakes of about M3.0 to 4.0 during the same period. The ground shaking may also cause landslides, mudslides, and avalanches on steeper hills or mountains, all of which can damage buildings and hurt people. In total, Otto Nuttli reported more than 200 moderate to large aftershocks in the New Madrid region between December 16, 1811, and March 15, 1812: ten of these were greater than about 6.0; about one hundred were between M5.0 and 5.9; and eighty-nine were in the magnitude 4 range. (NASA/JPL-Caltech/ESA/Copernicus) This buckles and bends the tectonic plate, a bit like a piece of wood, or a strip of thick rubber. Some of those affected by the huge quake have been e-mailingBBC News Online telling of their ordeals. [8] They are slower than body waves, roughly 90% of the velocity of S waves for typical homogeneous elastic media. The USGS Earthquake Hazards Program is part of the National Earthquake Hazards Reduction Program (NEHRP), established by Congress in 1977, and the USGS Advanced National Seismic System (ANSS) was established by Congress as a NEHRP facility. Ground shaking move buildings from side to side and up and down. As with other earthquakes, much of the damage was caused by buildings collapsing with people inside them, making earthquake-proof buildings a must. A seismic wave is a wave of acoustic energy that travels through the Earth or another planetary body.It can result from an earthquake (or generally, a quake), volcanic eruption, magma movement, a large landslide, and a large man-made explosion that produces low-frequency acoustic energy. Seismologists worldwide are still far from being able to predict where, when and how the next big one will strike. 0000006022 00000 n A daily update by email. 0000002679 00000 n Then, underneath Puebla state just south of Mexico City at a depth of about 30 miles below ground, the subducted plate abruptly changes direction once more. Think of a sturdy piece of wood. Earth, reflecting and refracting at each interface. A foreshock is a small earthquake that occurs before an earthquake's more intense shaking motion. Not all seismic waves are the same. This is good news for cities like Morelia, in Michoacn, where we believe the plates fabric runs almost perpendicular to the direction of the plates break the wrong setup for a strong earthquake. Large waves (seiches) were generated on the Mississippi River by seismically-induced ground motions deforming the riverbed. That means the capital could see another large quake. A strong correlation exists between modern seismicity and the uplift, indicating that stresses that produced the uplift may still exist today. The September 19 quake actually occurred on the 32nd anniversary of the magnitude-8.1 earthquake that killed at least 10,000 people in and around Mexico City in 1985. 0000002436 00000 n At teleseismic distances, the first arriving P waves have necessarily travelled deep into the mantle, and perhaps have even refracted into the outer core of the planet, before travelling back up to the Earth's surface where the seismographic stations are located. Robert Stoneley, 1929 2008.. Obituary of his son with reference to discovery of Stoneley waves. 0000004675 00000 n For spherically symmetric Earth the period for given n and l does not depend on m. Some examples of spheroidal oscillations are the "breathing" mode 0S0, which involves an expansion and contraction of the whole Earth, and has a period of about 20 minutes; and the "rugby" mode 0S2, which involves expansions along two alternating directions, and has a period of about 54 minutes. . One year has passed since a magnitude 7.1 earthquake struck Mexico City, toppling 40 buildings and killing over 300, but the memory remains fresh. When water-saturated granular material like sand loses its strength temporarily, it gets converted into a liquid state from solid, and hence liquefaction takes place. When the plate bends downward, some of the rocks in the plate break. Lake St. Francis, in eastern Arkansas, which was formed by subsidence during both prehistoric and the 1811-1812 earthquakes, is 64 kilometers long by 1 kilometer wide. Together, these instruments measure shaking across Mexico. This is often the basis for designing structures buried underground for smaller levels of acceleration than those above the ground. But it is bad news for neighboring Puebla and Oaxaca. As you move farther from the earthquake fault, the intensity of the shaking decreases. However, shaking strong enough to alarm the general population (intensity greater than or equal to V) occurred over an area of 2.5 million square kilometers. What our new study can do, we hope, is help Mexicans nationwide understand whats happening beneath their feet. Most of Alaska's mainland felt . But that doesnt mean the shaking above ground feels weak. The best way to shelter in place is to drop, cover, and hold on. Harbour Wave. Detailed info, map, data, reports, updates about this earthquake: Unconfirmed earthquake or seismic-like event: 17 mi northwest of Great Bend, Barton County, Kansas, USA, Thursday, Feb 23, 2023 at 3:36 pm (GMT -6) - 31 user experience reports It is also called Tidal Wave. After the bent tectonic plate snaps, seismic waves emanate outwards from the breaking point, causing the Earth to tremble. It dives almost vertically downward, plunging itself deep into the Earths mantle. hXMs6WHu""&kC)f#6I !5'Znzq^K&v!$_Rg [1[8S,F]|20V-RM$,[*}]("Ux"rQ[?6fc@Vb(&~?l+pV)O !nr%L A design level earthquake is the one that has the probability of exceedance of 2% in 50 years. COVER your head and neck (and your entire body if possible) underneath a sturdy table or desk. Science Journalist. extension that engages the longitudinal . Sometimes landslide is so big that it nearly destroys the hill completely. That catastrophe marked an entire generation of Mexicans, including ourselves, back when we were just kids. In the epicentral area the ground surface was described as in great convulsion with sand and water ejected tens of feet into the air (liquefaction). The magnitude-7.8 earthquake near Gaziantep that struck south-eastern Turkey and neighbouring Syria on 6 February , and the large aftershocks that followed, destroyed thousands of buildings and claimed tens of thousands of lives.. Clean-up of the wreckage of a collapsed building in Diyarbakr, Turkey. You will receive a link and will create a new password via email. If you use a cane: DROP, COVER, and HOLD ON or sit on a chair, bed, etc. 0000005859 00000 n Country Dense arrays of nearby sensors such as those that exist in California can provide accuracy of roughly a kilometer, and much greater accuracy is possible when timing is measured directly by cross-correlation of seismogram waveforms. After the bent tectonic plate snaps, seismic waves emanate outwards from the breaking point, causing the Earth to tremble. But then, just as it begins to jut underneath the Mexican mainland, the plate which is made of dense, heavy rocks reverses course. High-resolution images of the ocean bottom off Mexicos Pacific shore reveal that the seafloor terrain is rugged in a very organized fashion. If using a walker carefully get as low as possible. Friction between . In a rigid structure, all points in it move with the ground by the same amount, and hence experience the same maximum acceleration of PGA. Liquefaction of soil is one of the alternative effects of ground shaking. Your submission has been received! Only five earthquakes have struck this region in the past century . %%EOF Ground failure estimates from a 6.0 magnitude quake in India in 2021 USGS Using satellite imagery, the USGS was able to map more than 23,000 landslides that were triggered by the strong shaking. A large event felt on the East Coast that is sometimes regarded as the fourth principal earthquake of the 1811-1812 sequence. In the earth, rocks bend and then they break. Typically a location program will start by assuming the event occurred at a depth of about 33km; then it minimizes the residual by adjusting depth. . The principle on which it works is simple. trailer Since 1980, 40 perceptible earthquakes have hit this region. EQ 3: Prince William Sound, Alaska, March 27 th 1964: Richter Magnitude 9.2 Anchorage, about 120 kilometers northwest of the epicenter,sustained the most severe damage to property. [9] They are named after Augustus Edward Hough Love, a British mathematician who created a mathematical model of the waves in 1911. 0000002287 00000 n Join TheConstructor to ask questions, answer questions, write articles, and connect with other people. Only one life was lost in falling buildings at New Madrid, but chimneys were toppled and log cabins were thrown down as far distant as Cincinnati, Ohio, St. Louis, Missouri, and in many places in Kentucky, Missouri, and Tennessee. 0:00 / 4:50 Buildings Swaying 9.1 Earthquake - Scary Footage [Historical Speeches TV] Historical Speeches TV 175K subscribers Subscribe 15M views 4 years ago Japan - 11 March 2011 - Tsunami Wave. In most situations, you can protect yourself if you immediately: Any buildings in the path of these surface waves can lean or tip over from all the movement. In December 1992, a magnitude 7 earthquake caused a tsunami that killed about 2,500 people on Flores island in eastern Indonesia. Like a sheet of plywood, a tectonic plate is more resistant to pressure when bent against the grain. In fact, it was different than most big Mexican earthquakes, which typically happen along the countrys Pacific coast, where two tectonic plates collide. An accelerogram can be integrated to . Other areas subsided by as much as 5 meters, although 1.5 to 2.5 meters was more common. The town of New Madrid was destroyed. and down. An earthquake causes slope instability by shaking the slopy land in all possible directions. When recorded by a seismic observatory, their different travel times help scientists locate the quake's hypocenter. Thank you! earthquake. It is difficult to assign intensities to the principal shocks that occurred after 1811 because many of the published accounts describe the cumulative effects of all the earthquakes and because the Ohio River was iced over, so there was little river traffic and fewer human observers. This same, unstable subducted plate runs underneath all central Mexico. Zmrt Snmez, Executive P. October 14, 2021. Seismic waves are studied by seismologists, who record the waves using seismometers, hydrophones (in water), or accelerometers. For instance, a horizontal PGA value of 0.6g (= 0.6 times the acceleration due to gravity) suggests that the movement of the ground that can cause a maximum horizontal force on a rigid structure equal to 60% of its weight. 0000006574 00000 n Even so, the plates texture marked by this linear fabric of underground mountains and canyons turns out to be relevant in determining where these rare, bending earthquakes might occur. 12. Under such circumstances, the bent plate can more easily snap and break from continued tectonic movement. Thousands of people die every year because of earthquakes. Seismic waves are generated throughout the earthquake. 0000028023 00000 n This generally causes the sinking and tilting of rigid structures like buildings. And, thanks to But we still dont know how often bending earthquakes might happen whether once a century or every decade. Here's why: The taller a structure, the more flexible it is. The plates texture matters, too. 10 min read. It may take on 2l+1 values from l to +l. it's best if these are flexible rather than rigid so they can bend with the rolling ground. They cause most of the shaking at the ground surface during an Join TheConstructor to ask questions, answer questions, write articles, and connect with other people. The closer you are to the epicenter, the stronger the shaking. A notable area of subsidence that formed during the February 7, 1812, earthquake is Reelfoot Lake in Tennessee, just east of Tiptonville dome on the downdropped side of the Reelfoot scarp. They can be classified as a form of mechanical surface waves. Nepal Earthquake M7.9 Ground Motion Visualization. trace that shows the varying amplitude of ground oscillations beneath the And after an earthquake 225 miles away in Oaxaca state shook the capital city again on Feb. 16, 2018, the city mayor said hospitals treated dozens of people for panic attacks. People in central Mexico are accustomed to the ground shaking. Creating the Home of Your Dreams: Tips for Building the Perfect Home, Triaxial Shear Test on Soil | Lab Procedures | Advantages & Disadvantages of Triaxial Shear Test, Soil Erosion | Factors Affecting Erosion by Water | Types of Soil Erosion Due to Water, Peg in Surveying ( Survey Stakes) | 3 Types of Peg | Uses of Peg | Importance of Peg, 14 Unique Features To Consider When Building A Custom Home, Basic Home Fix-It Skills Everyone Should Know. Dream Civil is a group of 6 Civil Engineers and researchers. This is due to the appreciably increased velocities within the planet, and is termed Huygens' Principle. This kind of observation has also been used to argue, by seismic testing, that the Moon has a solid core, although recent geodetic studies suggest the core is still molten[citation needed]. The 1964 Alaska earthquake, the strongest earthquake ever recorded in North America, struck Alaska's Prince William Sound, about 74 miles southeast of Anchorage. This energy can be generated by a sudden dislocation of segments of the crust, by a volcanic eruption, or event by manmade explosions. The zone of potential 'bending' earthquakes, where the subducted tectonic plate that runs beneath Mexico juts downward at a sharp angle, is a band spanning the country from center to south . It is so much sudden that maximum people do not get the chance to escape. Earthquakes Earthquakes occur when energy stored in elastically strained rocks is suddenly released. Outside a building: Move into a clearing and away from power lines, trees and buildings. Our new paper in Geophysical Research Letters brings critical findings to light. After the bent tectonic plate snaps, seismic waves emanate outwards from the breaking point, causing the Earth to tremble. At a fixed distance from the fault, the larger the earthquake magnitude, the greater the shaking. This fabric was created about 8 million years ago, when the rocks first formed way before tectonic plates collided to give Mexico its subduction zone. Keep your cane near you so it can be used when the shaking stops. Free oscillations of the Earth are standing waves, the result of interference between two surface waves traveling in opposite directions. Shear waves can't travel through any liquid medium,[6] so the absence of S-waves in earth's outer core suggests a liquid state. We believe in quality and update every content semi-annually. That catastrophe marked an. The USGS and its partners monitor and report earthquakes, assess earthquake impacts and hazards, and . The two exceptions to this seem to be "g" and "n".[14][15]. In earthquake-prone areas like California, strain gauges are used to measure this bending and help seismologists, scientists who study earthquakes, understand more about predicting them. What type of ground causes the most destruction? In 1906, during the San Francisco earthquake, more people die due to the effect of fire rather than other effects of an earthquake. Particle motion of surface waves is larger than that of body waves, so surface waves tend to cause more damage. The closer you are to the epicenter, the stronger the shaking. A tsunami is a series of large waves caused by the displacement of a large volume of water due to an earthquake in an ocean or lake, a volcanic eruption in the sea or ocean, and many more. Which is the code used for the design of the RCC Bridge? }q-W]? A month before the massive earthquake struck southern Turkey, Japanese earthquake engineering experts visited the site to investigate changes in the ground surface caused by the earthquake and the state of damage to buildings. Most events occur at depths shallower than about 40km, but some occur as deep as 700km. The closer you are to the epicenter, the stronger the shaking. With the help of the ground accelerator, ground shaking is measured. Perceptible ground shaking was in the range of one to three minutes depending upon the observers location. Huge waves on the Mississippi River overwhelmed many boats and washed others high onto the shore. A seismic wave is a wave of acoustic energy that travels through the Earth or another planetary body. The shaking that any structure experiences depends on how far it is from the fault and the soil under and around it.