{"id":140232,"date":"2011-10-11T13:01:08","date_gmt":"2011-10-11T12:01:08","guid":{"rendered":"http:\/\/www.madrimasd.org\/blogs\/universo\/?p=140232"},"modified":"2011-10-11T13:01:50","modified_gmt":"2011-10-11T12:01:50","slug":"los-tipos-de-suelos-condicionan-las-repercusiones-de-los-seismos-o-terremotos","status":"publish","type":"post","link":"https:\/\/www.madrimasd.org\/blogs\/universo\/2011\/10\/11\/140232","title":{"rendered":"Los Tipos de Suelos Condicionan las Repercusiones de los Se\u00edsmos o Terremotos"},"content":{"rendered":"<p style=\"text-align: justify;\"><span style=\"color: #3366ff;\"><strong>Si usted vive en un \u00e1rea con altos riesgos s\u00edsmicos<\/strong><\/span>, obviamente no podr\u00e1 evitarlos. Sin embargo, <span style=\"color: #3366ff;\"><strong>s\u00ed pudiera estar en sus manos paliar el efecto sobre la vivienda en la que habita y la vida de sus seres queridos<\/strong><\/span>. Con tal prop\u00f3sito, <span style=\"color: #3366ff;\"><strong>basta elegir el tipo de suelos sobre los que se asentar\u00e1, as\u00ed como la posici\u00f3n fisiogr\u00e1fica en la que se edificar\u00e1<\/strong><\/span>. Si los terremotos son bastante imprevisibles, las repercusiones pueden paliarse con mayor precisi\u00f3n, aunque nunca exista certeza absoluta, por supuesto. A ha hora de escribir este post, \u00a0hace muy pocos meses que en Espa\u00f1a se sufri\u00f3 el <a href=\"http:\/\/es.wikipedia.org\/wiki\/Terremoto_de_Lorca_de_2011\">terremoto de Lorca<\/a> (2011) y d\u00edas atras en la <a href=\"http:\/\/www.madrimasd.org\/blogs\/ciencia_marina\/2011\/10\/10\/132108\">Isla de Hierro<\/a> (Archipi\u00e9lago Canario).\u00a0Por centrarnos en<strong><span style=\"color: #3366ff;\"> Lorca<\/span><\/strong>, no se trat\u00f3 de un evento de gran magnitud. Sin embargo las repercusiones fueron mayores de las que hubiera cabido esperar. La prensa se hizo eco del debate sobre las causas de tal desastre. Obviamente no puede compararse con los que suelen aparecer en la prensa mundial. Sin embargo, retorn\u00e9 por unas pocas horas al tema de la \u201c<a href=\"https:\/\/www.madrimasd.org\/blogs\/universo\/2008\/09\/19\/101307\">edafolog\u00eda de los desastres naturales<\/a>\u201d. Y, para mi sorpresa, detecte<strong><span style=\"color: #3366ff;\"> abundant\u00edsima informaci\u00f3n en<em> suahili<\/em><\/span><\/strong>, y pr\u00e1cticamente ninguna en espa\u00f1ol-castellano. Pues si, la cuesti\u00f3n estriba en que <span style=\"color: #3366ff;\"><strong>distintos tipos de suelo-regolito responden de forma diferente a los temblores, siendo las repercusiones sobre unos mucho m\u00e1s graves que en otros<\/strong><\/span>.\u00a0\u00a0<\/p>\n<p style=\"text-align: center;\">\u00a0<img decoding=\"async\" class=\"ngg-singlepic ngg-center\" src=\"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-content\/blogs.dir\/42\/files\/1283\/loma-prieta-cal-state-la-lomaprietasofsoil.jpg\" alt=\"loma-prieta-cal-state-la-lomaprietasofsoil\" width=\"425\" height=\"249\" \/><\/p>\n<p style=\"text-align: center;\"><a href=\"http:\/\/www.calstatela.edu\/dept\/geology\/Homes.htm\">Tipos de Suelos y Terremotos. Fuente Cal State LA.<\/a><\/p>\n<p style=\"text-align: justify;\"><!--more-->Desgraciadamente soy mortal, y disto en demas\u00eda de atesorar una formaci\u00f3n enciclop\u00e9dica. <span style=\"color: #3366ff;\"><strong>En Espa\u00f1a, la docencia de la edafolog\u00eda no suele incluir estos temas<\/strong><\/span>.\u00a0 M\u00e1s aun, debido a que las zonas de riesgo s\u00edsmico se encuentran muy localizadas y que aun en ellas los terremotos de gran magnitud son afortunadamente escasos, no suele ser un tema que despierta un gran inter\u00e9s en la opini\u00f3n p\u00fablica, hasta que algo ocurre, claro est\u00e1. Ahora bien muchos de los lectores de esta bit\u00e1cora proced\u00e9is de Latinoam\u00e9rica, en donde tales desastres son muy comunes y graves en ciertas regiones.<\/p>\n<p style=\"text-align: justify;\">Efectivamente, <span style=\"color: #3366ff;\"><strong>tanto las propiedades de los tipos de suelos como las de sus regolitos subyacentes condicionan las repercusiones de los terremotos que pueden acaecer en un territorio<\/strong>. De este modo, <strong>entre enclaves pr\u00f3ximos la susceptibilidad de que ocurran tragedias es mayor en unos lugares que en otros, incluso en distancias peque\u00f1as<\/strong><\/span>. En consecuencia, el ciudadano que tuviera tal posibilidad, podr\u00eda escoger lugares menos \u201cvulnerables\u201d que otros ante el impacto de estos eventos. <span style=\"color: #3366ff;\"><strong>Con independencia de la fisiograf\u00eda que condiciona las avalanchas y deslizamientos, las propiedades de los materiales<\/strong><\/span> ed\u00e1ficos son muy variadas. As\u00ed, por ejemplo, <strong><span style=\"color: #3366ff;\">las rocas blandas y porosas \/y m\u00e1s aun si se encuentran rellenas de agua) resultan ser m\u00e1s vulnerables que las duras y compactas. La resistencia a la tensi\u00f3n, la velocidad con que se\u00a0 transmiten las ondas y la licuefacci\u00f3n son elementos muy a tener en cuenta<\/span><\/strong>. De hecho, abajo podr\u00e9is observar <span style=\"color: #3366ff;\"><strong>una clasificaci\u00f3n de suelos-regolitos en funci\u00f3n de su vulnerabilidad ante el efecto de los se\u00edsmos<\/strong><\/span>. Tambi\u00e9n en sentido estrito, <span style=\"color: #3366ff;\"><strong>las propiedades de los tipos de suelos o edafotaxa \u201ccl\u00e1sicos\u201dresultan relevantes<\/strong><\/span>. \u00a0Sin embargo, es palmario que la ordenaci\u00f3n urban\u00edstica no suele basarse en las recomendaciones que al respecto suele ofrecer la ciencia. Basta viajar, observar el terreno y la localizaci\u00f3n de los asentamientos.<\/p>\n<p style=\"text-align: justify;\">Ni puedo ni me atrevo a realizar un resumen de todo el material que he detectado en Internet. Os dejo pues los contenidos y enlaces de varias p\u00e1ginas Web.\u00a0 Reitero que por desgracia tal documentaci\u00f3n se encuentra escrita en ingl\u00e9s. Ahora bien, no es de dif\u00edcil lectura. Incluso en algunos casos se dan instrucciones a los ciudadanos para que inspeccionen debidamente el terreno \u00a0(suelo y fisiograf\u00eda) antes de comprarlo para edificar su casa.\u00a0 <strong><span style=\"color: #3366ff;\">Espero que tal material sea \u00fatil con vistas a que los docentes divulguen sus contenidos tras una previa traducci\u00f3n a la ciudadan\u00eda<\/span>.<\/strong> La f\u00edsica de suelos no es precisamente uno de mis puntos fuertes. Lo lamento sinceramente!.<\/p>\n<p><span style=\"color: #008000;\"><strong>Juan Jos\u00e9 Ib\u00e1\u00f1ez <\/strong><\/span><\/p>\n<p style=\"text-align: center;\">\u00a0<img decoding=\"async\" class=\"ngg-singlepic ngg-center\" src=\"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-content\/blogs.dir\/42\/files\/1283\/typos-de-suelos-y-terremotos-diy-guides.jpg\" alt=\"typos-de-suelos-y-terremotos-diy-guides\" width=\"320\" height=\"379\" \/><\/p>\n<p style=\"text-align: center;\"><a href=\"http:\/\/www.diy-guides.com\/soil-types-affecting-earthquakes\">Tipos de Suelos y Terremotos. Fuente Tiy Guides<\/a><\/p>\n<p><strong><a href=\"http:\/\/earthquake.usgs.gov\/regional\/nca\/soiltype\">Soil Type and Shaking Hazard in the San Francisco Bay Area<\/a><\/strong><strong>\u00a0<\/strong><\/p>\n<p>Ground shaking is the primary cause of earthquake damage to man-made structures. When the ground shakes strongly, buildings can be damaged or destroyed and their occupants may be injured or killed.<\/p>\n<p style=\"text-align: justify;\">Seismologists have observed that some districts tend to repeatedly experience stronger seismic shaking than others. This is because the ground under these districts is relatively soft.<strong> Soft soils amplify ground shaking<\/strong>. If you live in an area that in past earthquakes suffered shaking stronger than that felt in other areas at comparable distance from the source, you are likely to experience relatively strong shaking in future earthquakes as well. An example of this effect was observed in San Francisco, where many of the same neighborhoods were heavily damaged in both the 1906 and 1989 earthquakes. <span style=\"color: #008080;\"><strong>The influence of the underlying soil on the local amplification of earthquake shaking is called the site effect<\/strong><\/span>.<\/p>\n<p style=\"text-align: justify;\">Other factors influence the strengh of earthquake shaking at a site as well, including the earthquake&#8217;s magnitude and the site&#8217;s proximity to the fault. These factors vary from earthquake to earthquake. In contrast, soft soil always amplifies shear waves. If an earthquake is strong enough and close enough to cause damage, the damage will usually be more severe on soft soils.<\/p>\n<p><span style=\"color: #008080;\"><strong>Soil Types and Shaking Amplification<\/strong><\/span><\/p>\n<p style=\"text-align: justify;\">One contributor to the site amplification is the velocity at which the rock or soil transmits shear waves (S-waves). Shaking is stronger where the shear wave velocity is lower.<strong> The National Earthquake Hazards Reduction Program (NEHRP) has defined 5 soil types based on their shear-wave velocity (Vs). We have modified these definitions slightly, based on studies of earthquake damage in the Bay Area. The modified definitions are as follows<\/strong>:<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #008080;\"><strong>Soil type A<\/strong> <\/span>Vs &gt; 1500 m\/sec Includes unweathered intrusive igneous rock. Occurs infrequently in the bay area. We consider it with type B (both A and B are represented by the color blue on the map). Soil types A and B do not contribute greatly to shaking amplification.<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #008080;\"><strong>Soil type B<\/strong> <\/span>1500 m\/sec &gt; Vs &gt; 750 m\/sec Includes volcanics, most Mesozoic bedrock, and some Franciscan bedrock. (Mesozoic rocks are between 245 and 64 million years old. The Franciscan Complex is a Mesozoic unit that is common in the Bay Area.)<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #008080;\"><strong>Soil Type C <\/strong><\/span>750 m\/sec &gt; Vs &gt; 350 m\/sec Includes some Quaternary (less than 1.8 million years old) sands, sandstones and mudstones, some Upper Tertiary (1.8 to 24 million years old) sandstones, mudstones and limestone, some Lower Tertiary (24 to 64 million years old) mudstones and sandstones, and Franciscan melange and serpentinite.<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #008080;\"><strong>Soil Type D<\/strong> <\/span>350 m\/sec &gt; Vs &gt; 200 m\/sec Includes some Quaternary muds, sands, gravels, silts and mud. Significant amplification of shaking by these soils is generally expected.<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #008080;\"><strong>Soil Type E<\/strong> <\/span>200 m\/sec &gt; Vs Includes water-saturated mud and artificial fill. The strongest amplification of shaking due is expected for this soil type.<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #008080;\"><strong>Caveats<\/strong><\/span><\/p>\n<p style=\"text-align: justify;\">Surface geology provides only a rough estimate of the site effect.<\/p>\n<p style=\"text-align: justify;\">Map boundaries are accurate only to within about 50 meters.<\/p>\n<p style=\"text-align: justify;\"><strong>Soft soils tend to overlie stiffer soils and bedrock. Sites on thin layers (less than 4 meters) of soft soil overlying stiff soil will behave more like sites on stiff soil<\/strong>.<\/p>\n<p style=\"text-align: justify;\"><strong>Some inaccuracy is introduced by assigning NEHRP soil-types to a geologic unit on the basis of the average velocity for that unit<\/strong>. For example, there is a widespread (in the bay area) unit consisting of Quaternary sand, gravel, silt and mud. It has been assigned a<strong> soil-type of C<\/strong>, based on its average velocity. While the average velocity is within the range of<strong> soil-type C<\/strong>, some of the slower-velocity soils within the unit fall into the range of<strong> soil-type D<\/strong>. Because the unit is undifferentiated in our digital geologic data set, we have no basis for identifying the slower-velocity soils.<\/p>\n<h3><a href=\"http:\/\/www.diy-guides.com\/soil-types-affecting-earthquakes\">Soil Types Affecting Earthquakes<\/a><\/h3>\n<p style=\"text-align: justify;\">The bodies of the Earth lay on tectonic plates that slide around underneath the surface. These plates when collide will create earthquakes that shake the ground and cause damage to both the earth and to the nearby structures and lifeforms. F<strong>or property owners who want to lower the risk of having a problematic living place, they should learn how to assess certain soil characteristics that make the property more resistant to the earthquake\u2019s shaking<\/strong>. <strong>Property owners can construct their buildings on solid bedrock too<\/strong>.<\/p>\n<div><strong><span style=\"color: #008080;\">Here are among soil types that can be affected through earthquakes:<\/span><\/strong><strong>\u00a0<\/strong><strong>\u00a0<\/strong><\/div>\n<p style=\"text-align: justify;\">Sedimentary basins and deep valleys have loose soil that goes very deep thus shaking the most as these areas have a lower altitude.<\/p>\n<p style=\"text-align: justify;\"><strong>There are many cities built in valleys in basins that could lead to earthquakes and sometimes to something more catastrophic.<\/strong><\/p>\n<p style=\"text-align: justify;\"><strong>For earthquakes occurring in soft soil, high raise buildings and bridges sustain most of the damage. Soil at higher altitudes does not carry as many vibrations and have more potential for landslides<\/strong>.<\/p>\n<p style=\"text-align: justify;\"><strong>Areas that have lots of rock and highly compacted soil are the best earthquakes resistant<\/strong>. The hard rock areas will resist the shaking and do not break easily. The areas that are artificially filled with loose sand and once very wet, would suffer the most during an earthquake.<\/p>\n<p style=\"text-align: justify;\"><strong>The more condensed and compact the soil, the more hardened the rock that the soil contains resulted less than the soil transfer vibrations. Looser soil tends to transmit vibrations that lead to more destruction during earthquakes<\/strong>. Over time, it can create more damage as the vibrations are also longer on looser soil.<\/p>\n<p><strong>Soil liquidification<\/strong> is the loss of strength in saturated soil after a buildup of pore water pressures during the dynamic loading.<\/p>\n<p>Soils have the ability to resist force that comes horizontally or known as shear resistance.<\/p>\n<p><strong>Soils subjected to earthquakes can lose their shear resistance that will cause the soil to flow around in semi-liquid<\/strong> form, which can cause a lot of damage to structures resting on soil.<\/p>\n<p><strong>This liquidification is the most destructive effects in low-laying areas with poor compacted artificial fill<\/strong>. It can come up from the ground through cracks and make the sand deposit all over and deform the land permanently.<\/p>\n<h3><a href=\"http:\/\/mceer.buffalo.edu\/favicon.ico\">Soils and Earthquakes<\/a><\/h3>\n<p><strong><span style=\"color: #008080;\">What is Soil?<\/span><\/strong><\/p>\n<p>A surficial material formed by chemical, physical, and biological weathering.<\/p>\n<p><span style=\"color: #008080;\"><strong>What Variables Control the Soil in an Area?<\/strong><\/span><\/p>\n<p>Climate and weather<\/p>\n<p>Topography<\/p>\n<p>Time<\/p>\n<p>Parent material<\/p>\n<p>Vegetation (dependent on the climate, weather and water)<\/p>\n<p>Biological and chemical agents<\/p>\n<p><span style=\"color: #008080;\"><strong>How Do Soils Vary?<\/strong><\/span><\/p>\n<p><strong>Grain size and hardness <\/strong>(There are 3 basic particle sizes that create the 3 basic soil types: sand, silt, and clay.)<\/p>\n<p>Color<\/p>\n<p><strong>Grain size and shape<\/strong><\/p>\n<p>Chemical composition<\/p>\n<p>Amount of pore spaces &#8211; open spaces filled with air<\/p>\n<p>Amount of moisture<\/p>\n<p>Permeability<\/p>\n<p><span style=\"color: #008080;\"><strong>Why is Soil Important to Consider in an Earthquake<\/strong>?<\/span><\/p>\n<p>Although structures are supported on soil, most of us rarely consider soil, its differences, and its subsequent effect on structures in an earthquake. <strong>Some soil is hard, like rock, and can support over 40 tons per square foot <\/strong>(Levy &amp; Salvadori, 1992), <strong>while other soil is weak, like loose sand. Different soil properties can affect seismic waves as they pass through a soil layer<\/strong>. <strong>In some areas, there may be many different types of soils layered one upon another before hard rock is encountered. Sometimes, ground shaking will be amplified<\/strong>. This will influence what needs to be done to structures to help them fare better in an earthquake. Also, a phenomenon known as<strong> liquefaction or ground failure can occur in moderate to major earthquakes<\/strong>.<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #008080;\"><strong>What is Liquefaction?<\/strong><\/span><\/p>\n<p style=\"text-align: justify;\"><strong>When there is ground water less than 30 feet from the surface in soils that contain layers of sand, the pressures generated by repetitive squeezing of the earth by several seconds of seismic wave vibrations will cause the ground water to flow up and out.<\/strong> When this occurs, the sand grains, which have no strength except when touching each other, are forced apart.<strong> The ground then takes on the properties of a semi-solid<\/strong>. When it happens over a large area, houses and buildings with inadequate foundations may actually sink slightly. <strong>When liquefaction happens in a small area, liquefied sand can be ejected to the surface through fissures in the overlying layers. Soil failure, as described earlier, will have a larger impact on pipelines and pile foundations, and other structures below the surface of the earth<\/strong>.<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #008080;\"><strong>Does Liquefaction Always Occur During an Earthquake?<\/strong><\/span><\/p>\n<p style=\"text-align: justify;\">No. Liquefaction occurs only under ideal conditions as a result of an earthshaking event and is <strong>controlled by the following <span style=\"color: #008080;\">variables<\/span><\/strong>:<\/p>\n<p style=\"text-align: justify;\">Grain size of the soil<\/p>\n<p style=\"text-align: justify;\">Duration of the earthquake and amplitude and frequency of shaking<\/p>\n<p style=\"text-align: justify;\">Distance from the epicenter<\/p>\n<p style=\"text-align: justify;\">Location of the water table<\/p>\n<p style=\"text-align: justify;\">Cohesiveness of the soil<\/p>\n<p style=\"text-align: justify;\">Permeability of the layer<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #008080;\"><strong>Where Do I Begin?<\/strong><\/span><\/p>\n<p style=\"text-align: justify;\">Investigation of the soil is a good place to start. Get a sample from your yard or the yard next door. Examine it with a magnifying glass. Draw a picture of how the soil looks under the magnifying glass. Start a soil collection.<\/p>\n<p style=\"text-align: justify;\">What color(s) are the grains?<\/p>\n<p style=\"text-align: justify;\">What general color is the soil?<\/p>\n<p style=\"text-align: justify;\">What size(s) are the particles?<\/p>\n<p style=\"text-align: justify;\">Do the particles have rounded or sharp edges?<\/p>\n<p style=\"text-align: justify;\">Is there anything living in the soil?<\/p>\n<p style=\"text-align: justify;\">Is it moist or dry?<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #008080;\"><strong>Soil Profile<\/strong><\/span><\/p>\n<p style=\"text-align: justify;\">A soil profile is a cross section of soil layers with different characteristics. You can make one with a clear plastic tube.<\/p>\n<p style=\"text-align: justify;\">Carefully dig a hole as deep as the tube is long.<\/p>\n<p style=\"text-align: justify;\">put a bit of soil from the bottom of the hole into the bottom of the tube.<\/p>\n<p style=\"text-align: justify;\">take soil a few inches from the bottom and place it in the tube.<\/p>\n<p style=\"text-align: justify;\">Continue this procedure until the tube is full of soil.<\/p>\n<p style=\"text-align: justify;\">Next, evaluate and note the soil profile characteristics with the following questions:<\/p>\n<p style=\"text-align: justify;\">Do the colors of layers vary?<\/p>\n<p style=\"text-align: justify;\">Where is the darkest soil? The lightest?<\/p>\n<p style=\"text-align: justify;\">Where are the most stones?<\/p>\n<p style=\"text-align: justify;\">What can you learn by looking at the different layers?<\/p>\n<p style=\"text-align: justify;\">Is the soil further down in a hole always the same as it is at the top?<\/p>\n<p style=\"text-align: justify;\"><strong>Materials:<\/strong><\/p>\n<p style=\"text-align: justify;\">fine, well sorted sand (i.e., most grains the same size)<\/p>\n<p style=\"text-align: justify;\">flexible plastic cup<\/p>\n<p style=\"text-align: justify;\">8-12&#8243; pie pan<\/p>\n<p style=\"text-align: justify;\">1 oz. or larger sinker<\/p>\n<p style=\"text-align: justify;\">beaker,125 ml water<\/p>\n<p style=\"text-align: justify;\">Procedure:<\/p>\n<p style=\"text-align: justify;\">Carefully cut off the bottom portion of the plastic cup (within 1 1\/2 cm from the bottom).<\/p>\n<p style=\"text-align: justify;\">Invert cup and place in the middle of the pie pan.<\/p>\n<p style=\"text-align: justify;\">Pressing down on the cup, slowly pour the sand into the inverted cup to a level approximately 12 cm from the top. Make sure the sand is level, but do not try to compact it.<\/p>\n<p style=\"text-align: justify;\">Gently place a sinker or comparable object on the surface of the sand.<\/p>\n<p style=\"text-align: justify;\">Holding onto the cup, slowly pour 125 ml of water outside the cup into the pan. Record the time it takes for the water to migrate or move upward to saturate the sand (permeability).<\/p>\n<p style=\"text-align: justify;\">Firmly holding the cup in place, tap forcibly on the side of the cup. What happens to the sinker?<\/p>\n<p style=\"text-align: justify;\">What did you learn from this experiment?<\/p>\n<p style=\"text-align: justify;\"><strong><em>Additional Resources<\/em><\/strong>:<\/p>\n<p style=\"text-align: justify;\">Earthquake Engineering Research Institute. (January 1994). Earthquake basics: Liquefaction what it is and what to do about it.<\/p>\n<p style=\"text-align: justify;\">Hilston, P., &amp; Hilston, C. R. (1993). A field guide to planet earth: Projects for reading rocks, rivers, mountains, and the forces that shape them. Chicago, IL: Chicago Review Press.<\/p>\n<p style=\"text-align: justify;\">Jennings, T. (1989). The young scientist investigates: Rocks and soil. Chicago: Chicago Children&#8217;s Press.<\/p>\n<p style=\"text-align: justify;\">Levy, M., &amp; Salvadori, M. (1992). Why buildings fall down: How structures fail. NY: W. W. Norton.<\/p>\n<p style=\"text-align: justify;\">Model developed by: Len Sharp, Robert Allers, Borys Browar, Daniel Parke, John Rice, Richard Thomas.<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #008080;\"><strong>Ver tambi\u00e9n el contenido de este pdf.<\/strong><\/span><\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/www.sciencebuddies.org\/science-fair-projects\/project_ideas\/Geo_p037.shtml\">http:\/\/www.sciencebuddies.org\/science-fair-projects\/project_ideas\/Geo_p037.shtml<\/a><\/p>\n<p style=\"text-align: justify;\"><strong>Is soil structure an important factor in earthquake dynamics? Investigate soil liquefaction and how different soil types respond to earthquake movements<\/strong>. <strong>Are movements more dramatic in sandy\/loamy or clay type soils? Which soil structures are most stable? Which are the most volatile? <\/strong>(MCEER, 2005)<\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/www.sciencebuddies.org\/science-fair-projects\/project_ideas\/Geo_p037.shtml\">MCEER, 2005. \u00abSoils and Earthquakes,\u00bb Multidisciplinary Center for Earthquake Engineering Research [accessed 2\/25\/06] <\/a><\/p>\n<p style=\"text-align: justify;\">Earthquake and Soil liquefaction Kikipedia<\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/en.wikipedia.org\/wiki\/Soil_liquefaction\">http:\/\/en.wikipedia.org\/wiki\/Soil_liquefaction<\/a><\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/www.ehow.com\/list_7741881_soil-types-affecting-earthquakes.html\">Soil Types Affecting Earthquakes | eHow.com<\/a><\/p>\n<p style=\"text-align: justify;\">www.ehow.com \u203a <a href=\"http:\/\/www.google.es\/url?url=http:\/\/www.ehow.com\/home-safety-and-household-tips\/&amp;rct=j&amp;sa=X&amp;ei=XXotTsjYMZDCswb3ndUT&amp;ved=0CFkQ6QUoADAE&amp;q=soils+earthwakes&amp;usg=AFQjCNFGqIiaZvxYhUPiT_AzTGSc_UMs6Q\">Home Safety &amp; Household Tips<\/a> &#8211; <a href=\"http:\/\/webcache.googleusercontent.com\/search?q=cache:W9_Y7AoM2GoJ:www.ehow.com\/list_7741881_soil-types-affecting-earthquakes.html+soils+earthwakes&amp;cd=5&amp;hl=es&amp;ct=clnk&amp;gl=es&amp;source=www.google.es\">En\u00a0cach\u00e9<\/a><\/p>\n<p style=\"text-align: justify;\">Soil Types Affecting Earthquakes. Bodies of Earth rest on tectonic plates, which slide around underneath the surface. When these plates collide, &#8230;<\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/scholar.lib.vt.edu\/theses\/available\/etd-219182249741411\/unrestricted\/Chp02.pdf\">Chapter 2 Soil Liquefaction in Earthquakes<\/a><\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/books.google.com\/books\/about\/Liquefaction_of_soils_during_earthquakes.html?id=oD4rAAAAYAAJ\">Liquefaction of soils during earthquakes &#8211; Google Books<\/a><\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/www.google.es\/url?url=http:\/\/www.google.com\/search%3Ftbo%3Dp%26tbm%3Dbks%26q%3Dsubject:%2522Technology%2B%2526%2BEngineering%2522&amp;rct=j&amp;sa=X&amp;ei=XXotTsjYMZDCswb3ndUT&amp;ved=0CG0Q6QUoADAG&amp;q=soils+earthwakes&amp;usg=AFQjCNEWHi5astbd6IBVOZRzCFb7s7ce6Q\">Technology &amp; Engineering<\/a> \u203a <a href=\"http:\/\/www.google.es\/url?url=http:\/\/www.google.com\/search%3Ftbo%3Dp%26tbm%3Dbks%26q%3Dsubject:%2522Technology%2B%2526%2BEngineering%2BCivil%2522&amp;rct=j&amp;sa=X&amp;ei=XXotTsjYMZDCswb3ndUT&amp;ved=0CG4Q6QUoATAG&amp;q=soils+earthwakes&amp;usg=AFQjCNHp5vyZHjcagWez2Z6P2pVvxlD9Xw\">Civil<\/a> \u203a <a href=\"http:\/\/www.google.es\/url?url=http:\/\/www.google.com\/search%3Ftbo%3Dp%26tbm%3Dbks%26q%3Dsubject:%2522Technology%2B%2526%2BEngineering%2BCivil%2BGeneral%2522&amp;rct=j&amp;sa=X&amp;ei=XXotTsjYMZDCswb3ndUT&amp;ved=0CG8Q6QUoAjAG&amp;q=soils+earthwakes&amp;usg=AFQjCNFGnhEr7pqsjTOJxrMyQgs6e9hKeg\">General<\/a><\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/bssa.geoscienceworld.org\/cgi\/content\/refs\/53\/2\/309\">Response of soils, foundations, and earth structures to the &#8230;<\/a><\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/www.newswise.com\/articles\/earthquake-soil-effects-study-could-improve-buildings\">Earthquake Soil Effects Study Could Improve Buildings<\/a><\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/www.vulcanhammer.net\/geotechnical\/soil-dynamics.php\">Soil Dynamics, Special Topics and Earthquake Engineering<\/a><\/p>\n<p style=\"text-align: justify;\">www.vulcanhammer.net\/geotechnical\/soil-dynamics.php &#8211; <a href=\"http:\/\/webcache.googleusercontent.com\/search?q=cache:BCudve9lV68J:www.vulcanhammer.net\/geotechnical\/soil-dynamics.php+soils+earthwakes&amp;cd=10&amp;hl=es&amp;ct=clnk&amp;gl=es&amp;source=www.google.es\">En\u00a0cach\u00e9<\/a><a href=\"http:\/\/www.google.es\/search?hl=es&amp;rlz=1R2GGLL_es&amp;biw=1262&amp;bih=428&amp;q=related:www.vulcanhammer.net\/geotechnical\/soil-dynamics.php+soils+earthquakes&amp;tbo=1&amp;sa=X&amp;ei=XXotTsjYMZDCswb3ndUT&amp;ved=0CIkBEB8wCQ\">Similares<\/a><\/p>\n<p style=\"text-align: justify;\">Vibratory Motions; Mass, Stiffness, Damping; Amplification Function; Earthquake Ground Motions. SOIL PROPERTIES. Soil Properties for Dynamic Loading &#8230;<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #008080;\"><strong>Buscando por \u201csoils earthwakes\u201d en Google<\/strong><\/span><\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/www.ehow.com\/list_7741881_soil-types-affecting-earthquakes.html\">Soil Types Affecting Earthquakes | eHow.com<\/a><\/p>\n<p style=\"text-align: justify;\">www.ehow.com \u203a <a href=\"http:\/\/www.google.es\/url?url=http:\/\/www.ehow.com\/home-safety-and-household-tips\/&amp;rct=j&amp;sa=X&amp;ei=XXotTsjYMZDCswb3ndUT&amp;ved=0CFkQ6QUoADAE&amp;q=soils+earthwakes&amp;usg=AFQjCNFGqIiaZvxYhUPiT_AzTGSc_UMs6Q\">Home Safety &amp; Household Tips<\/a> &#8211; <a href=\"http:\/\/webcache.googleusercontent.com\/search?q=cache:W9_Y7AoM2GoJ:www.ehow.com\/list_7741881_soil-types-affecting-earthquakes.html+soils+earthwakes&amp;cd=5&amp;hl=es&amp;ct=clnk&amp;gl=es&amp;source=www.google.es\">En\u00a0cach\u00e9<\/a><\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/scholar.lib.vt.edu\/theses\/available\/etd-219182249741411\/unrestricted\/Chp02.pdf\">Chapter 2 Soil Liquefaction in Earthquakes<\/a><\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/books.google.com\/books\/about\/Liquefaction_of_soils_during_earthquakes.html?id=oD4rAAAAYAAJ\">Liquefaction of soils during earthquakes &#8211; Google Books<\/a><\/p>\n<p style=\"text-align: justify;\">books.google.com \u203a <a href=\"http:\/\/www.google.es\/url?url=http:\/\/www.google.com\/search%3Ftbo%3Dp%26tbm%3Dbks%26q%3Dsubject:%2522Technology%2B%2526%2BEngineering%2522&amp;rct=j&amp;sa=X&amp;ei=XXotTsjYMZDCswb3ndUT&amp;ved=0CG0Q6QUoADAG&amp;q=soils+earthwakes&amp;usg=AFQjCNEWHi5astbd6IBVOZRzCFb7s7ce6Q\">Technology &amp; Engineering<\/a> \u203a <a href=\"http:\/\/www.google.es\/url?url=http:\/\/www.google.com\/search%3Ftbo%3Dp%26tbm%3Dbks%26q%3Dsubject:%2522Technology%2B%2526%2BEngineering%2BCivil%2522&amp;rct=j&amp;sa=X&amp;ei=XXotTsjYMZDCswb3ndUT&amp;ved=0CG4Q6QUoATAG&amp;q=soils+earthwakes&amp;usg=AFQjCNHp5vyZHjcagWez2Z6P2pVvxlD9Xw\">Civil<\/a> \u203a <a href=\"http:\/\/www.google.es\/url?url=http:\/\/www.google.com\/search%3Ftbo%3Dp%26tbm%3Dbks%26q%3Dsubject:%2522Technology%2B%2526%2BEngineering%2BCivil%2BGeneral%2522&amp;rct=j&amp;sa=X&amp;ei=XXotTsjYMZDCswb3ndUT&amp;ved=0CG8Q6QUoAjAG&amp;q=soils+earthwakes&amp;usg=AFQjCNFGnhEr7pqsjTOJxrMyQgs6e9hKeg\">General<\/a><\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/bssa.geoscienceworld.org\/cgi\/content\/refs\/53\/2\/309\">Response of soils, foundations, and earth structures to the &#8230;<\/a><\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/www.newswise.com\/articles\/earthquake-soil-effects-study-could-improve-buildings\">Earthquake Soil Effects Study Could Improve Buildings<\/a><\/p>\n<p style=\"text-align: justify;\">18 Jul 2011 \u2013 Japan&#8217;s March 11 Tohoku Earthquake, among the strongest ever recorded, is providing scientists with a treasure trove of data on rare &#8230;<\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/www.vulcanhammer.net\/geotechnical\/soil-dynamics.php\">Soil Dynamics, Special Topics and Earthquake Engineering<\/a><\/p>\n<p style=\"text-align: justify;\">Vibratory Motions; Mass, Stiffness, Damping; Amplification Function; Earthquake Ground Motions. SOIL PROPERTIES. Soil Properties for Dynamic Loading &#8230;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Si usted vive en un \u00e1rea con altos riesgos s\u00edsmicos, obviamente no podr\u00e1 evitarlos. Sin embargo, s\u00ed pudiera estar en sus manos paliar el efecto sobre la vivienda en la que habita y la vida de sus seres queridos. Con tal prop\u00f3sito, basta elegir el tipo de suelos sobre los que se asentar\u00e1, as\u00ed como la posici\u00f3n fisiogr\u00e1fica en la que se edificar\u00e1. Si los terremotos son bastante imprevisibles, las repercusiones pueden paliarse con mayor precisi\u00f3n, aunque nunca exista certeza absoluta, por supuesto. A ha hora de escribir este post, \u00a0hace muy pocos meses que en Espa\u00f1a se sufri\u00f3 el\u2026<\/p>\n","protected":false},"author":26,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0},"categories":[603,597,607,587,617,611],"tags":[1618,47088,9229,9834,46703],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":4}},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/140232"}],"collection":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/users\/26"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/comments?post=140232"}],"version-history":[{"count":9,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/140232\/revisions"}],"predecessor-version":[{"id":140500,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/posts\/140232\/revisions\/140500"}],"wp:attachment":[{"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/media?parent=140232"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/categories?post=140232"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madrimasd.org\/blogs\/universo\/wp-json\/wp\/v2\/tags?post=140232"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}