61. Science Blog -- New Technology To Help Measurement And Study Of Earthquakes New Technology To Help measurement and Study of earthquakes The continuous,earthquakerelated measurements from the GPS network will allow scientists http://www.scienceblog.com/community/older/1996/A/199600304.html

From: National Science Foundation New Technology To Help Measurement and Study of Earthquakes Scientists have begun installing a network of 250 Global Positioning System (GPS) receivers that will continuously measure the constant, yet physically imperceptible, movements of earthquake faults throughout southern California. This information should help researchers forecast future earthquake hazards in the greater Los Angeles area. "GPS is the most important new technology to emerge for the study of earthquakes in decades," says Tom Henyey, director of the Southern California Earthquake Center (SCEC) in Los Angeles, a National Science Foundation Science and Technology Center. "This information will allow us to improve our estimates of the regional earthquake hazard in southern California and to prioritize earthquake mitigation activities, including emergency preparedness and retrofit strategies. Continuous GPS measurements will also allow for more rapid regional damage assessment after large earthquakes." GPS is a constellation of 24 Earth-orbiting satellites, arranged so that several are "visible" from any point on the surface of the Earth at any time. A user on the ground with a GPS receiver can determine his or her precise location by measuring signals from the GPS satellites.

62. Science Blog - New Technology To Help Measurement And Study Of Earthquakes The continuous, earthquakerelated measurements from the GPS network will allow The GPS measurements will also be useful during and after earthquakes. http://www.scienceblog.com/community/older/archives/C/archsf580.html

Press Release NSF PR 96-67 - October 30, 1996 This material is available primarily for archival purposes. Telephone numbers or other contact information may be out of date; please see current contact information at media contacts New Technology to Help Measurement and Study of Earthquakes Scientists have begun installing a network of 250 Global Positioning System (GPS) receivers that will continuously measure the constant, yet physically imperceptible, movements of earthquake faults throughout southern California. This information should help researchers forecast future earthquake hazards in the greater Los Angeles area. "GPS is the most important new technology to emerge for the study of earthquakes in decades," says Tom Henyey, director of the Southern California Earthquake Center (SCEC) in Los Angeles, a National Science Foundation Science and Technology Center. "This information will allow us to improve our estimates of the regional earthquake hazard in southern California and to prioritize earthquake mitigation activities, including emergency preparedness and retrofit strategies. Continuous GPS measurements will also allow for more rapid regional damage assessment after large earthquakes." GPS is a constellation of 24 Earth-orbiting satellites, arranged so that several are "visible" from any point on the surface of the Earth at any time. A user on the ground with a GPS receiver can determine his or her precise location by measuring signals from the GPS satellites.

63. How To Map An Earthquake: A Guide From Ordnance Survey earthquake damage. Seismologists have always needed a way to measure how strongthe earthquake was at different places, and this measure is called intensity http://www.ordnancesurvey.co.uk/oswebsite/education/schools/classroom/mapearthqu

This website looks much better and has extra features in a browser that supports the latest web standards. Find out more www.ordnancesurvey.co.uk/ education Site help ... ABOUT US How to map an earthquake Site home page Education Schools Ideas for classroom use ... Digital maps for the Internet Roger Musson, British Geological Survey, West Mains Road, Edinburgh, EH9 3LA When an earthquake has happened, usually the first question people ask is, 'How big was it?' A seismologist will answer this question by quoting a value called the magnitude – this is a number representing the amount of energy released by the earthquake. It's this number that is popularly referred to as the 'Richter scale'. An increase of one unit represents a thirty-fold increase in energy, so an earthquake like the one that ruined Kobe in Japan in 1995 (magnitude nearly 7) was about 900 times as powerful as the earthquake felt in England and Wales in 1990 (magnitude about 5). However, there is another question that can be asked: 'How strong was it?' The strength with which earthquake shaking can be felt is very different from the magnitude, as it varies with distance from the epicentre of the earthquake. An earthquake may cause destruction near its epicentre, but as you go further away the damage becomes less and less. After a certain distance there will be no damage at all, but people will still feel the vibration, and even further away the shaking will be so weak people will not even feel it. Earthquake intensity Seismologists have always needed a way to measure how strong the earthquake was at different places, and this measure is called intensity. An interesting thing about intensity is that it's much easier to measure than magnitude. To calculate the magnitude of an earthquake, seismologists take measurements from a seismogram, which is a recording made by a measuring instrument, a seismometer. Although it is possible for amateurs with a knowledge of electronics to build their own seismometers as a hobby, professional instruments are expensive to buy and run. But measuring intensity is something that anyone can do.

64. USGS Earthquake Hazards Program-FAQ - Frequently Asked Questions How are earthquakes measured? How is the magnitude of an earthquake determined? A earthquake size, as measured by the Richter Scale is a well known, http://earthquake.usgs.gov/faq/meas.html

Latest Quakes For Kids Only Regional Websites HOME ... SEARCH Frequently Asked Questions FAQ Home Current EQs Myths EQs,Faults,etc ... Other Resources Measuring Earthquakes Q: Where can I buy a Richter scale? A: The Richter scale is not a physical device, but a mathematical formula. The magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded on a seismogram at a certain period. See next question and answer. For further information, see: Q: How are earthquakes recorded? How are earthquakes measured? How is the magnitude of an earthquake determined? A: Earthquakes are recorded by a seismographic network. Each seismic station in the network measures the movement of the ground at the site. The slip of block of rock over another in an EQ releases energy that makes the ground vibrate. That vibration pushes the adjoining piece of ground and cause it to vibrate and thus the energy travel out from the EQ in a wave. There are many different ways to measure different aspects of an earthquake. Magnitude is the most common measure of an earthquake's size. It is a measure of the size of the earthquake source and is the same number no matter where you are or what the shaking feels like. The Richter scale measures the largest wiggle on the recording, but other magnitude scales measure different parts of the earthquake.

65. Earthquake Glossary A measure of the size of an earthquake based on the area of fault rupture, theaverage amount of slip, and the force that was required to overcome the http://earthquake.usgs.gov/4kids/eqterms.html

Latest Quakes For Kids Only Regional Websites HOME ... SEARCH For Kids Only Earthquake Glossary See also the Earthquake Image Glossary and A B C D ... I J K L M N ... T U V W X Y Z acceleration. When you step on the accelerator in the car or put on the brakes, the car goes faster or slower. When it is changing from one speed to another, it is accelerating (faster) or decelerating (slower). This change from one speed, or velocity, to another is called acceleration. During an earthquake when the ground is shaking, it also experiences acceleration. The peak acceleration is the largest acceleration recorded by a particular station during an earthquake. accelerogram. The recording of the acceleration of the ground during an earthquake. accelerograph. An instrument that records the acceleration of the ground during an earthquake, also commonly called an accelerometer.

66. The South-East Asia Earthquake And Tsunami Blog earthquake and Tsunami Alert Andaman Islands. An earthquake measuring 7.2 onthe Richter scale, with its epicentre 135 kms west of Car Nicobar has been http://tsunamihelp.blogspot.com/

67. EARTHQUAKE MAGNITUDES earthquake data set 2 consists of a single earthquake measured at many differentstations. Calculate mb or Ms for each station. http://lasker.princeton.edu/ScienceProjects/curr/eqmag/eqmag.htm

Contents for Earthquake Magnitudes Goals and Objectives Activity 1. Introduction to earthquake magnitudes Activity 2. Calculating your own earthquake magnitudes Activity 3. Powers of Ten (Orders of magnitude) ... Research Ideas for Earthquake Magnitudes Target Class Grades 9-12, Earth Science Goals and Objectives To learn that there are many ways to calculate earthquake magnitudes, and to become familiar with some different scales scientists have developed to calculate magnitudes. Use the Seismic Wave Analysis Program (SWAP) to calculate PEPP earthquake magnitudes. Understand powers of ten (orders of magnitudes). Understand that averaging magnitude calculations over many seismic stations gives a better estimate of earthquake magnitude than using one or a few stations. Explore the relationship between earthquake magnitude and the energy released by an earthquake. Study wave properties, such as wave propagation, using magnitude determinations. Back to Table of Contents Activity 1. Introduction to Earthquake Magnitudes Objective: Use the PEPP Learning Library to become familiar with the different ways scientists calculate earthquake magnitudes.

68. Earthquakes In Japan The Japanese shindo scale for measuring earthquakes is more commonly used inJapan than the Richter scale. Shindo refers to the intensity of an earthquake http://www.japan-guide.com/e/e2116.html

Travel Living Japan A-Z Forum ... Living in Japan Earthquakes Search this site Related Pages Living in Japan Travel Geography Great Kanto Earthquake 1923 ... Kobe japan-guide.com newsletter Our newsletter keeps you up to date on Japan travel and living related issues and site updates. Click here to subscribe! japan-guide.com forum Any questions? Ask them on the question forum Travel Topics Travel Tour Packages Car Rental Hotel Reservations ... Organized Tours The Japanese archipelago is located in an area where several continental and oceanic plates meet. This is the cause for frequent earthquakes and the presence of many volcanoes and hot springs across Japan. If earthquakes occur below or close to the ocean, they may trigger tidal waves (tsunami). Historic earthquakes Many parts of the country have experienced devastating earthquakes and tidal waves in the past. The worst earthquake in Japanese history hit the Kanto plain around Tokyo in the year 1923, when over 100,000 people died in the Great Kanto Earthquake In January 1995 a strong earthquake hit the city of Kobe and surroundings. The Southern Hyogo Earthquake (also called Great Hanshin Earthquake) killed 6,000 and injured 415,000 people. 100,000 houses were completely and 185,000 partially destroyed.

69. Virtual Earthquake - An Introduction In order to locate the epicenter of an earthquake you will need to examine its On each of these seismograms you will have to measure the S P time http://www.sciencecourseware.com/VirtualEarthquake/VQuakeExecute.html

Page 1 of 12 What's an earthquake? Earthquakes occur because of a sudden release of stored energy. This energy has built up over long periods of time as a result of tectonic forces within the earth. Most earthquakes take place along faults in the upper 25 miles of the earth's surface when one side rapidly moves relative to the other side of the fault. This sudden motion causes shock waves (seismic waves) to radiate from their point of origin called the focus and travel through the earth. It is these seismic waves that can produce ground motion which people call an earthquake. Each year there are thousands of earthquakes that can be felt by people and over one million that are strong enough to be recorded by instruments. Strong seismic waves can cause great local damage and they can travel large distances. But even weaker seismic waves can travel far and can be detected by sensitive scientific instruments called seismographs What are earthquake (Seismic) Waves?

70. 10(m) Earthquakes The strength of an earthquake can be measured by a device called a seismograph.When an earthquake occurs this device converts the wave energy into a http://www.physicalgeography.net/fundamentals/10m.html

FUNDAMENTALS OF PHYSICAL GEOGRAPHY HOME FUNDAMENTALS ONLINE TEXTBOOK GLOSSARY ... ABOUT CHAPTER 10: Introduction to the Lithosphere (m). Earthquakes Introduction An earthquake is a sudden vibration or trembling in the Earth. More than 150,000 tremors strong enough to be felt by humans occur each year worldwide. Earthquake motion is caused by the quick release of stored potential energy into the kinetic energy of motion. Most earthquakes are produced along faults tectonic plate boundary zones , or along the mid-oceanic ridges Figures 10m-1 and ). At these areas, large masses of rock that are moving past each other can become locked due to friction . Friction is overcome when the accumulating stress has enough force to cause a sudden slippage of the rock masses. The magnitude of the shock wave released into the surrounding rocks is controlled by the quantity of stress built up because of friction, the distance the rock moved when the slippage occurred, and ability of the rock to transmit the energy contained in the seismic waves . The San Francisco earthquake of 1906 involved a 6 meter horizontal displacement of bedrock. Sometime after the main shock wave

71. Glossary Of Terms: E Measurements indicate that the average Earth albedo is approximately 30 %. earthquake Focus; Point of stress release in an earthquake. http://www.physicalgeography.net/physgeoglos/e.html

GLOSSARY OF TERMS HOME FUNDAMENTALS ONLINE TEXTBOOK GLOSSARY ... Z Glossary of Terms: E Earth Albedo Is the reflectivity of the Earth's atmosphere and surface combined. Measurements indicate that the average Earth albedo is approximately 30 %. Earthflow A rapid type of downslope mass movement that involves soil and other loose sediments . Usually triggered by water saturation from rainfall. Earthquake Is a sudden motion or trembling in the Earth. The motion is caused by the quick release of slowly accumulated energy in the form of seismic waves . Most earthquakes are produced along faults tectonic plate boundaries, or along the mid-oceanic ridges Earthquake Focus Point of stress release in an earthquake Earth Revolution Refers to the orbit of the Earth around the sun . This celestial motion takes 365 1/4 days to complete one cycle. Further, the Earth's orbit around the sun is not circular, but elliptical.

72. NSL: Living With Earthquakes In Nevada In fact, earthquakes are very complex. Measuring their size is something like Seismologists measure different earthquake dimensions with different http://www.seismo.unr.edu/ep/nvguide/sbg4.html

Home Earthquake Preparedness > Living with Earthquakes in Nevada Main Page The Earthquake Threat Nevada is Earthquake Country Confronting the Inevitable Earthquakes in Nevada - 1850s to 1998 What are the Chances of Experiencing Strong Shaking? ... What will Happen if a Disastrous Earthquake Strikes? Earthquake Preparedness Taking Control Your Personal Safety Life with Aftershocks Home Safe Home ... The Anatomy of a Safe Building Science Background Reviewing the Basics The Big Picture Faults in Nevada Measuring an Earthquake ... What will the Shaking Feel Like Earthquake Safety The Road to Earthquake Safety Earthquake Plan Further Reading Living with Earthquakes in Nevada: A Nevadan's guide to preparing for, surviving, and recovering from an earthquake Measuring an Earthquake Click for larger image Knowing how fast the waves travel, seismologists calculate a time and location of the earthquake that gives the pattern of shaking that was recorded .They measure the time of the wave that arrives first. That is the wave traveling from the hypocenter, the first part of the fault to slip. Arrival times and locations can be determined by a computer within minutes. Determining the location of the rest of the fault plane, beyond the hypocenter, requires more complicated procedures and can take several hours to days. Horizontal Motion Seismograph Measuring the size of an earthquake How big was the earthquake? That should be easy. Why do scientists have problems coming up with a simple answer to a simple question? Many Nevadans have felt this frustration after earthquakes, as seismologists often seem to contradict one another. In fact, earthquakes are very complex. Measuring their size is something like trying to determine the "size" of an abstract modern sculpture with only the use of a tape measure. Which dimension do you measure?

73. Richter Magnitude large number of earthquakes, and developed a calibrated system of measuring Richter showed that, the larger the intrinsic energy of the earthquake, http://www.seismo.unr.edu/ftp/pub/louie/class/100/magnitude.html

What is Richter Magnitude? Short answer: Seismologists use a Magnitude scale to express the seismic energy released by each earthquake. Here are the typical effects of earthquakes in various magnitude ranges: Earthquake Severity Richter Earthquake Magnitudes Effects Less than 3.5 Generally not felt, but recorded. 3.5-5.4 Often felt, but rarely causes damage. Under 6.0 At most slight damage to well-designed buildings. Can cause major damage to poorly constructed buildings over small regions. 6.1-6.9 Can be destructive in areas up to about 100 kilometers across where people live. 7.0-7.9 Major earthquake. Can cause serious damage over larger areas. 8 or greater Great earthquake. Can cause serious damage in areas several hundred kilometers across. Although each earthquake has a unique Magnitude , its effects will vary greatly according to distance, ground conditions, construction standards, and other factors. Seismologists use a different Mercalli Intensity Scale to express the variable effects of an earthquake.

74. Modified Mercalli Intensity Of the two ways to measure earthquake size, magnitude based on instrumentalreadings and intensity based on qualitative effects of earthquakes, http://www.eas.slu.edu/Earthquake_Center/mercalli.html

Earthquake Intensity Of the two ways to measure earthquake size, magnitude based on instrumental readings and intensity based on qualitative effects of earthquakes, only intensity can be applied to pre-instrumental earthquakes. The 1931 Modified Mercalli scale used in the United States assigns a Roman numeral in the range I - XII to each earthquake effect. The methodology is simple. At each location assign a numeral to describe the earthquake effect Contour the zones of similar effect The earthquake is assumed to have occurred near the region of maximum intensity The earthquake may be characterized by the largest Roman numeral assigned to it The problems with intensity are multifold. First, it is a qualitative assessment that measures different phenomena. The lower values address human response to ground motions, the intermediate values characterize the response of simple structures, and the upper values describe ground failure processes. Another problem is that incomplete spatial coverage may lead to a mislocation of the earthquake or an underassessment of its size. This is easily visualized for offshore earthquakes or, in the case of the United States, inadequate population distribution at the time of the earthquake. Modified Mercalli Scale Average peak velocity (centimeters per second) Intensity value and description Average peak acceleration (g is gravity=9.80 meters per second squared)

75. Geodynamics: Cascadia Subduction Zone measurement of Subduction Zone Deformation. Locked Subduction Zone Subductionthrustearthquakes or mega-earthquakes are known to be one stage of a http://www.pgc.nrcan.gc.ca/geodyn/cascadia.htm

Earthquake Processes: Cascadia Subduction Zone Measurement of Subduction Zone Deformation Subduction-thrust earthquakes or mega-earthquakes are known to be one stage of a subduction-thrust Earthquake Cycle The techniques mentioned above are high-precision geodetic techniques which have been developed to the required accuracy only recently. Another method called Very Long Baseline Interferometry (VLBI) uses the most fundamental reference system available, extragalactic quasars. A version of this system is being developed in Canada in a co-operative venture involving a number of Canadian scientific agencies: Geodetic Survey of Canada, Institute for Space and Terrestrial Science (ISTS), National Research Council (NRC) and Geological Survey of Canada. A number of other ways of measuring crustal deformation are 1) repeated resurveying of old geodetic survey networks, 2) repeated resurveying of old levelling lines, 3) repeated resurveying of gravity networks, and 4) measurement of changes in mean sea level (MSL). All of the high-precision methods used in the study of crustal deformation are being carried out in co-operation with the Geodetic Survey of Canada, while MSL studies are enabled through the cooperation of the Canadian Hydrographic Survey. Using the Global Positioning System (GPS) satellites, and a network of permanent GPS receivers, the relative motion of points on the earth's surface can be monitored at the level of a few millimetres per year. The arrows in this diagram show the measured annual rates and directions of motion of specific sites of the

76. ScienceMaster - JumpStart - Earthquakes - Frequently Asked Questions How do you measure the shaking that you feel during an earthquake? Measuringearthquakes. How are EQs recorded? By a seismographic network. http://www.sciencemaster.com/jump/earth/quakes_faq.php

Today is JumpStart - Earth Science Earthquakes* Frequently Asked Questions The October 17, 1989, Loma Prieta, California,Earthquake Ground shaking triggered liquefaction in a subsurface layer of sand, producing differential lateral and vertical movement in a overlying carapace of unliquified sand and silt, which moved from right to left towards the Pajaro River. This mode of ground failure, termed "lateral spreading", is a principal causet of liquefaction-related earthquake damage. Photograph by S.D. Ellen, U.S. Geological Survey Introduction One of the most frightening and destructive phenomena of nature is a severe earthquake and its terrible aftereffects. An earthquake is a sudden movement of the Earth, caused by the abrupt release of strain that has accumulated over a long time. For hundreds of millions of years, the forces of plate tectonics have shaped the Earth as the huge plates that form the Earth's surface slowly move over, under, and past each other. Sometimes the movement is gradual. At other times, the plates are locked together, unable to release the accumulating energy. When the accumulated energy grows strong enough, the plates break free. If the earthquake occurs in a populated area, it may cause many deaths and injuries and extensive property damage. Today we are challenging the assumption that earthquakes must present an uncontrollable and unpredictable hazard to life and property. Scientists have begun to estimate the locations and likelihoods of future damaging earthquakes. Sites of greatest hazard are being identified, and definite progress is being made in designing structures that will withstand the effects of earthquakes.

77. Tech Topics: Earthquakes: Measuring Earthquakes photos, and descriptions of seismographs, which have measured earthquakes overtime. A seismograph takes the motion of an earthquake and turns it into a http://www.thetech.org/exhibits/online/topics/32a.html

Humans have lived with earthquakes for a long time, and many cultures have developed ways to measure them. Devices that measure the strength (or magnitude), length, location (or epicenter), and direction of earthquakes are called seismographs. You will see how seismographs work, and how they have become more and more accurate over time. You'll find some interesting pictures, photos, and descriptions of seismographs, which have measured earthquakes over time. A seismograph takes the motion of an earthquake and turns it into a seismogram, or a graph of the earth's movement. Quick Menu: Earthquakes Measurement Seismographs Epicenter ... Activity 1

78. University Of Bergen Magazine 2002 - When The Earth Quakes An earthquake measuring 6.0 on the Richter Scale is equivalent to a single Hiroshima The most powerful earthquake ever measured (in Chile in 1960) had a http://www.uib.no/elin/elpub/uibmag/en01/earthquake.html

Receive printed issue Contents 2001 When the Earth quakes Every day, thousands of earthquakes take place all over the world. Most of them can hardly be noticed, but now and again, they really go off with a bang. When that happens, it is a busy time for earthquake scientist Kuvvet Atakan and his colleagues in the Norwegian National Network for Earthquake Research at the University of Bergen. Text: Hilde Bøyum. Photo: Odd Mehus Kuvvet Atakan is one of those people who are always at work; earthquakes do not respect normal working hours. When there was an earthquake on the Norwegian island of Sotra on December 8 last year his phone was rung off its hook in the middle of the night by the media, the police and ordinary members of the public. He was interviewed in front of the TV2 cameras while he logged on to the University of Bergen's computer system from his house in order to keep an eye on the earthquake. Kuwet Atakan registers earthquakes from all over the world at the University of Bergen's Seismological Observatory.

79. SpiNet | 1960 Chilean Earthqauke This makes MW a more accurate measurement of an earthquakes characteristics.Chile, an example The magnitude of earthquakes is difficult to measure, http://www.scieds.com/spinet/historical/chile_mag.html

The 1960 Great Chilean Earthquake Quicklinks 1960 Chile Main page Geography and Geology Damage and relief The great tsunami ... Historical great earthquakes Magnitude Scales Earthquake magnitude is a relative scale of earthquake size based on measurement of different seismic wave amplitudes. Richter Scale / M L - The first seismic magnitude scale was developed by Charles Richter in the early 1930's and was motivated by his desire to issue the first catalogue of southern California earthquakes. This catalogue contained several hundred events, whose size ranged from barely perceptible to large, and Richter felt that an earthquake description must include some objective measurement of size to assess its significance. Richter observed that the ground motion generated by an earthquake decreased similarly for many earthquakes. By comparing the ground motion recorded by the seismometer, one could assign a relative size to earthquakes. All of Richter's observations were made from data recorded on one type of seismometer, a simple Wood-Anderson torsion instrument. In designing his magnitude scale, Richter determined the relative size of an earthquake by comparing it to a reference earthquake recorded on a Wood-Anderson seismometer at a distance of 100 km from the epicenter. The calculation of magnitude is done using the amplitude of the S wave (secondary or shear wave). This magnitude scale is called the Richter Magnitude or ML - for local magnitude.

80. Ground Shakers' Earthquakes There are two main types of scales that are used to measure earthquakes.The Richter scale, and the Mercalli scale. The Richter scale is one of the scales http://library.thinkquest.org/03oct/00433/measurement.htm

Measurement There are two main types of scales that are used to measure earthquakes. The Richter scale, and the Mercalli scale. The Richter scale is one of the scales that is used to measure earthquakes. It is most commonly used in the United States, where as the Mercalli scale is used more globally. The Richter scale was invented by Charles Francis Richter. Charles Francis Richter was born on April 26 th 1900 in Hamilton Idaho. He was an American seismologist which is a person that studies earthquakes. He is most commonly known as the creator of the Richter scale, which was first used in 1935. He created the scale with his longtime friend Beno Gutenberg. He studied at the University of Southern California; and went to the California Institute of Technology in 1936. The Richter has nine different levels of earthquake severity. The Richter scale is a logarithmic scale, meaning that each level on the scale is actually ten points away from the other. Levels one and two, are most generally not felt by people, and are normally only sensed by sensitive seismographs. Even though they are not felt, they are still recorded. Levels 3 to 5.5 are usually felt by people as well as seismographs, but do not cause as much damage or movement as those higher on the scale. Usually, an earthquake in this range only causes such movement as slight shaking of glass, or perhaps a hanging picture falling off onto the floor.

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