Geometry.Net - Basic_E: Earthquake Measurement

California Earthquake-Measurement Field Sites
California earthquakemeasurement Field Sites. This map of California shows theStanford field sites as solid circles and some of the most notable faults as
http://www-star.stanford.edu/~acfs/Field_sitesMap.html
Aftenposten Norway, Norwegian News In English
earthquake measurement was Rocknes impact Instruments at the GeophysicalInstitute at Bergen University reveal three powerful measurements in the area
http://www.aftenposten.no/english/local/article714926.ece

Extractions: Rate calculator ... Here's a way to search a leading Norwegian telephone catalogue. Read more Aftenposten makes it easy to tune in to 18 Norwegian radio stations. CHOOSE CHANNEL HERE Advice and resources to help you find your Norwegian roots. LEARN MORE HERE Instruments at the Geophysical Institute at Bergen University reveal three powerful measurements in the area where the Rocknes capsized, just before the ship overturned. Experts can see no other explanation for the readings other than the ship striking bottom, newspaper Bergens Tidende reports. Related stories: Unstable "Rocknes" floats higher Bondevik promises aid after accident Survivors say doomed ship ran aground Three dead, 15 missing in ship disaster
Electronic Desktop Project - Virtual Earthquake
You are to locate the epicenter of an earthquake by making simple measurement on In order to get this certificate, you must make careful measurements
http://www.sciencecourseware.com/VirtualEarthquake/

Extractions: Virtual Earthquake is an interactive Web-based activity designed to introduce you to the concepts of how an earthquake EPICENTER is located and how the RICHTER MAGNITUDE of an earthquake is determined. The Virtual Earthquake program is running on a Web Server at California State University at Los Angeles. You can interact with Virtual Earthquake NEW : A completely revised version of Virtual Earthquake can be found HERE . This new applet-based version is more inquiry-based than the original version and contains tools so instructors can assess student learning. Currently it runs only under IE on PCs. (After you complete Virtual Earthquake, check out the Geology Labs On-Line home page for the latest information about project activities. Activities about age dating, river discharge and river flooding are available.) Instructors: here is some important information
FEMA For Kids: Disaster Connection - Kids To Kids
The intensity of an earthquake can be measured. One measurement is called theRichter scale. earthquakes below 4.0 on the Richter scale usually do not cause
http://www.fema.gov/kids/quake.htm

Extractions: Shake With The Quake Story Rumble Tumble Story are the shaking, rolling or sudden shock of the earth’s surface. Earthquakes happen along "fault lines" in the earth’s crust. Earthquakes can be felt over large areas although they usually last less than one minute. Earthquakes cannot be predicted although scientists are working on it! Most of the time, you will notice an earthquake by the gentle shaking of the ground. You may notice hanging plants swaying or objects wobbling on shelves. Sometimes you may hear a low rumbling noise or feel a sharp jolt. A survivor of the 1906 earthquake in San Francisco said the sensation was like riding a bicycle down a long flight of stairs. Earthquakes are sometimes called temblors, quakes, shakers or seismic activity. The most important thing to remember during an earthquake is to DROP, COVER and HOLD ON. So remember to DROP to the floor and get under something for COVER and HOLD ON during the shaking.
EVPP 110 Lecture
earthquake measurement. Richter scale; measures vibrational amplitude of earths earthquake- measurement. Mercalli scale; does NOT measure energy
http://mason.gmu.edu/~klargen/110lectphysicalenvironmentplatetectonicsfall03.htm

Extractions: Fall 2003, Instructor: Dr. Largen Physical Environment: Plate Tectonics, Earthquakes, Volcanoes Plate Tectonics Theory of plate tectonics Shapes of continents beginning centuries ago in 1915 Alfred Wegener (German,1880-1930) meterologist wrote The Origin of Continents and Oceans in 1915 Wegeners continental drift proposed all large continents of current world were joined together in late Paleozoic Era as single supercontinent, called Pangaea
Locating And Measuring Earthquakes - Putting Down Roots In Earthquake Country
In fact, earthquakes are very complex. Measuring their size is something like Seismologists have since developed a new measurement of earthquake size,
http://www.earthquakecountry.info/roots/measuring.html

Extractions: @import url("Roots/roots.css"); @import url("Roots/steps.css"); Earthquakes and faults Earthquake shaking Earthquakes are recorded by a seismic network. Each seismic station in the network measures the movement of the ground at that site. In an earthquake, the slip of a block of rock over another releases energy that makes the ground vibrate. That vibration pushes the adjoining piece of ground, causing it to vibrate, and thus the energy travels out from the earthquake in a wave. As the wave passes by a seismic station, that piece of ground vibrates and this vibration is recorded. (a compressional wave), and the S-wave (a shear wave). The S-wave is slower but larger than the P-wave and does most of the damage. Scientists have used knowledge of the differences between these and other seismic waves to learn a great deal about the interior of the earth. Knowing how fast seismic waves travel through the earth, seismologists can calculate the time when the earthquake occurred and its location by comparing the times when shaking was recorded at several stations. This process used to take almost an hour when done manually. Now computers determine this information automatically within minutes. Within a few more hours the shape and location of the entire portion of the fault that moved can be calculated. "IT'S HOT AND DRY EARTHQUAKE WEATHER!"
Geodynamics: Earthquake Processes
earthquake Processes. Cascadia Subduction Zone. measurement of Subduction ZoneDeformation; Current measurement Techniques; Cascadia earthquake Activity
http://www.pgc.nrcan.gc.ca/geodyn/eqpro.htm
InforMARE - Press Review
earthquake measurement was Rocknes impact. Instruments at the GeophysicalInstitute at Bergen University reveal three powerful measurements in the area
http://www.informare.it/news/review/2004/aftenposten0046.asp

Extractions: 'Earthquake' measurement was "Rocknes" impact Instruments at the Geophysical Institute at Bergen University reveal three powerful measurements in the area where the Rocknes capsized, just before the ship overturned. Experts can see no other explanation for the readings other than the ship striking bottom, newspaper Bergens Tidende reports. "The readings are consistent with the boat scraping along the mountain edge first. Afterwards we have the first, powerful impacts," Institute professor Jens Havskov told the newspaper
Research Products
Borcherdt, RD, 1997, earthquake groundmotion measurement for public safety,Proc., 29th Joint Meeting UJNR Panel on Wind and Seismic Effects, Tsukuba,
http://nsmp.wr.usgs.gov/publications/research_products.html

Extractions: HOME ABOUT NSMP DATA PROCESSING RECENT EVENTS ... LINKS RESEARCH PRODUCTS Recent (1997-2002) strong-motion products are grouped below by topic (principal researchers listed after topic): Earthquake Engineering M. Çelebi Çelebi, M.,1997, Response of Olive View Hospital to Northridge and Whittier earthquakes: Journal of Structural Engineering, April 1997, p. 389-396. Çelebi, M., 1997, National strong-motion program of the U.S. Geological Survey, Joint Meeting of the UJNR Panel on Wind and Seismic Effects, 29th, Tsukuba, Japan, May 12-25, 1997. Çelebi, M., and Liu, H-P., 1997, Before and after retrofit - Response of a building during ambient and strong-motions: National Conference on Wind Engineering, 8th, Proc., Baltimore, MD. Çelebi, M., 1998, GPS and/or strong and weak motion structural response measurements case studies, American Society for Civil Engineering (ASCE) Conference, San Francisco, July 1998.
Hot News
There was a local avalanche earthquake on 3 Oct 2001, measurement of SO2emission using COSPEC within this week noted an average of SO2 was 80 ton per
http://www.vsi.esdm.go.id/news/632.html

Extractions: Within the week, Karangetang seismicity was showing a significant increasing of deep volcanic earthquake, while other seismicity which associated with Karangetang eruption (avalanche, tremor and explosion earthquake) did not recorded. Some times glowing lava avalanche occurred from main crater rim on 1 and 2 Oct 2001. Plume emission from northern main crater was in white medium-thick color reached 600 m, while from crater II hit about 50-150 m height. Red color reflection was observed as height as 50 m. Complete seismicity during the week is listed as follow: 47 events of deep volcanic (VA), 3 events of shallow volcanic (VB), 44 events of tectonic and 1 event of multiphase earthquake.
MSN Encarta - Earthquake
Even with precise instrumental measurement of past earthquakes, however, As an example, after the 1906 San Francisco earthquake, the measurements showed
http://encarta.msn.com/encyclopedia_761571674_5/Earthquake.html

Extractions: Search for books and more related to Earthquake Encarta Search Search Encarta about Earthquake Editors' Picks Great books about your topic, Earthquake ... Click here Advertisement document.write(' Page 5 of 6 Encyclopedia Article Multimedia 17 items Article Outline Introduction Anatomy of an Earthquake Causes Distribution ... Extraterrestrial Quakes B Earthquake education and preparedness plans can help significantly reduce death and injury caused by earthquakes. People can take several preventative measures within their homes and at the office to reduce risk. Supports and bracing for shelves reduce the likelihood of items falling and potentially causing harm. Maintaining an earthquake survival kit in the home and at the office is also an important part of being prepared. In the home, earthquake preparedness includes maintaining an earthquake kit and making sure that the house is structurally stable. The local chapter of the American Red Cross is a good source of information for how to assemble an earthquake kit. During an earthquake, people indoors should protect themselves from falling objects and flying glass by taking refuge under a heavy table. After an earthquake, people should move outside of buildings, assemble in open spaces, and prepare themselves for aftershocks. They should also listen for emergency bulletins on the radio, stay out of severely damaged buildings, and avoid coastal areas in the event of a tsunami.
MSN Encarta - Print Preview - Earthquake
They measure the pattern of an earthquake with a machine called a seismograph . Even with precise instrumental measurement of past earthquakes, however,
http://encarta.msn.com/text_761571674___33/Earthquake.html

Extractions: Print Print Preview Earthquake Article View On the File menu, click Print to print the information. Earthquake VIII. Studying Earthquakes Seismologists measure earthquakes to learn more about them and to use them for geological discovery. They measure the pattern of an earthquake with a machine called a seismograph. Using multiple seismographs around the world, they can accurately locate the epicenter of the earthquake, as well as determine its magnitude, or size, and fault slip properties. A. Measuring Earthquakes All magnitude scales give relative numbers that have no physical units. The first widely used seismic magnitude scale was developed by the American seismologist Charles Richter in 1935. The Richter scale measures the amplitude, or height, of seismic surface waves. The scale is logarithmic, so that each successive unit of magnitude measure represents a tenfold increase in amplitude of the seismogram patterns. This is because ground displacement of earthquake waves can range from less than a millimeter to many meters. Richter adjusted for this huge range in measurements by taking the logarithm of the recorded wave heights. So, a magnitude 5 Richter measurement is ten times greater than a magnitude 4; while it is 10 x 10, or 100 times greater than a magnitude 3 measurement. Today, seismologists prefer to use a different kind of magnitude scale, called the moment magnitude scale, to measure earthquakes. Seismologists calculate moment magnitude by measuring the seismic moment of an earthquake, or the earthquakeâs strength based on a calculation of the area and the amount of displacement in the slip. The moment magnitude is obtained by multiplying these two measurements. It is more reliable for earthquakes that measure above magnitude 7 on other scales that refer only to part of the seismic waves, whereas the moment magnitude scale measures the total size. The moment magnitude of the 1906 San Francisco earthquake was 7.6; the Alaskan earthquake of 1964, about 9.0; and the 1995 KÅbe, Japan, earthquake was a 7.0 moment magnitude; in comparison, the Richter magnitudes were 8.3, 9.2, and 6.8, respectively for these tremors.
Urban Legends Reference Pages: Legal (Shake's Peers 'n' Gov)
(The Mercalli scale is a measurement derived from observable earthquake damage;the Richter scale is based on seismometer readings.
http://www.snopes.com/legal/fema.htm

Extractions: [Harvey, 1994] [Collected on the Internet, 2000] Right after the Northridge earthquake in 1994, word was going around that the State of California coerced CalTech to declare the magnitude of the earthquake under 7.0. This was due to a hidden clause in the state laws saying state income tax in California is suspended that year for affected areas when there is a major earthquake over 7.0 on the Richter Scale. Origins: On 17 January 1994, Los Angeles area residents were shaken awake at 4:31 A.M. by the seismic event that would come to be known as the Northridge quake. In the usual way of earthquakes, those few seconds of violent shaking took a terrible toll. The quake killed 57 people, injured another 9,000, and caused property damage in the $13-$15 billion range. It closed seven freeway sites and two hospitals, and left 150,000 people without water, 40,000 without natural gas, and 25,000 without homes. It was devastatingly awful. Folks were shocked when the quake was reported to have registered a mere 6.7 on the Richter scale. They were thus prepared to believe almost anything that would confirm the quake's intensity to have been much higher.
"Seizing" Up The Quake: The Measurement
Seizing Up the Quake The measurement By Trista L. Pollard How do they knowwhat magnitude the earthquake registers on the Richter scale?
http://www.edhelper.com/ReadingComprehension_37_22.html

Extractions: When an earthquake begins, the compressional or P waves are the first to arrive. This is usually in the form of a sharp thud. Next, the shear waves or S waves join in the seismic party (moving at 5 kilometers per second). The last waves to arrive are the surface waves. There are two types of surface waves called Love waves and Rayleigh waves Love waves, also called L waves, were named after British mathematician A.E.H. Love. He designed a mathematical model for L waves in 1911. L waves move from side to side, and they are the fastest surface wave. They also cause destructive vibrations in buildings and break water and gas lines. The "ground rolling feeling" of an earthquake is produced by L waves. On seismographs, L waves also produce the largest vibrations.
Measurement
The benefit of this type of measurement is that it gives a consistent and uniformmeasure of the size of an earthquake of any magnitude anywhere in the
http://scign.jpl.nasa.gov/learn/eq8.htm

Extractions: Measurement Earthquakes can be measured in several ways. The first way is to describe the earthquake's intensity. Intensity is the measure, in terms of degrees, of damage to the surface and the effects on humans. Intensity records only observations of effects on the crust, not actual ground motion or wave amplitudes which can be recorded by instruments. While intensity helps to determine how large of an area was effected, it is not an accurate measure of the earthquake for many reasons. Two such reasons are: only the effect on an area showing the greatest intensity is reported, which can imply a greater or lesser intensity than what actually occurred, and the way in which seismic waves travel varies as they pass through different types of rocks, so some areas near by may feel nothing because they are built on faulted rock, while other areas quite a distance from the foci will feel the effects because they are built on compact homogenous rocks. The second type of measurement is the magnitude of the earthquake. Magnitude does not depend on population and effects to ground structures, but rather on wave amplitude and distance. Magnitude is determined using mathematical formulae and information from seismograms. One such magnitude scale is the Richter scale. This magnitude scale is logarithmic, meaning each step in magnitude is exponentially greater than the last.
Earthquake & Seismic Information Page
WHAT IS THE DIFFERENCE BETWEEN THE RICHTER AND MERCALLI SCALES OF EARTHQUAKEmeasurement? What is the ModifiedMercalli Scale measurement?
http://www.wreg.com/Global/story.asp?S=242861
Measurement (from Earthquake) -- Britannica Student Encyclopedia
measurement (from earthquake) A seismograph records the pattern of shock waveson a revolving drum of paper. These wavy lines show the strength of the
http://www.britannica.com/ebi/article-199870

Extractions: Home Browse Newsletters Store ... Subscribe Already a member? Log in This Article's Table of Contents Introduction Causes Shock Waves Measurement Active Regions and Plate Tectonics Forecasting Reducing Earthquake Hazards Additional references about earthquake ... Print this Table of Contents Shopping Price: USD $1495 Revised, updated, and still unrivaled. The Official Scrabble Players Dictionary (Hardcover) Price: USD $15.95 The Scrabble player's bible on sale! Save 30%. Merriam-Webster's Collegiate Dictionary Price: USD $19.95 Save big on America's best-selling dictionary. Discounted 38%! More Britannica products earthquake Student Encyclopedia Article Page 4 of 8 Measurement A seismograph records the pattern of shock waves on a revolving drum of paper. These wavy lines show the strength of the various seismic waves and the times at which they occur. The tracing is called a seismogram. The study of earthquakes is seismology.
FIELD-Q
Measuring instruments were installed both on the east and the west caissons and measurement during earthquake is a dynamic measurement that starts
http://taisinkouwandata.ceri.go.jp/english/index3.html

Extractions: At the temporary quay wall of No.4 Wharf in the West District of the Port of Kushiro, the Hokkaido Regional Development Bureau has constructed full-scale test quay walls in a project to observe the dynamic behavior of a gravity quay wall during earthquakes. Called the project focuses on the following: Figure 1 shows the locations of the full-scale test caissons installed at No.4 Wharf in the West District of the Port of Kushiro. Figure 2 shows a plane view of the test quay wall. The three test caissons were placed in the east-west section of an L-shaped temporary quay wall. The caissons were designed to have a safety factor against sliding of 1.0 for earthquake motion whose horizontal acceleration is 100 Gal, on the basis of the current standard design method. Four units of earth pressure cell panels were installed behind each test caisson (Figure 3). To observe the effects of liquefaction countermeasures, sheet piles were installed in a row and a liquefaction countermeasure incorporating a sand compaction pile was provided only on the east side of the sheet piles. Measuring instruments were installed both on the east and the west caissons and
Maryland Geological Survey: Earthquakes In Maryland
measurement of the severity of an earthquake can be expressed in several ways, Magnitude is an objective measure of earthquake severity and is closely
http://www.mgs.md.gov/esic/brochures/earthquake.html

Extractions: Maryland's earthquake monitoring network is online. Visit the Seismic Network Pages for more information, and see live seismic displays. You can download a PDF version of this brochure, suitable for printing. Click here to get mdquakes.pdf By James P. Reger Earthquakes can be among the most devastating and terrifying of natural hazards. Although floods, tornadoes and hurricanes account for much greater annual loss in the United States, severe earthquakes pose the largest risk in terms of sudden loss of life and property. There are many interrelated factors that determine the extent of loss of property and life from an earthquake. Each of the following should be prefaced with "other factors being equal. . . ." Amount of seismic energy released: The greater the vibrational energy, the greater the chance for destruction. Duration of shaking: This is one of the most important parameters of ground motion for causing damage. Depth of focus, or hypocenter: The shallower the focus (the point of an earthquake's origin within the earth), usually the greater the potential for destructive shock waves reaching the earth's surface. Even stronger events of much greater depth typically produce only moderate shaking at ground level.
Earthquakes
Magnitude is a measure of energy released in an earthquake by measuring theamplitude of ground motion with a seismograph. This measurement is given on the
http://www.gsa.state.al.us/gsa/eq2/eq.html

Extractions: EARTHQUAKES IN ALABAMA Charleston, South Carolina, earthquake of 1886 Source: U.S. Geological Survey EARTHQUAKE HAZARDS EARTHQUAKE SIZE EARTHQUAKE MYTHS EARTHQUAKES AND ALABAMA ... HISTORIC ALABAMA EARTHQUAKES EARTHQUAKE HAZARDS National maps of earthquake shaking hazards provide information essential to creating and updating the seismic design provisions of building codes used in the United States. The 1996 U.S. Geological Survey shaking-hazard map for the United States is based on current information about the rate at which earthquakes occur in different areas and on how far strong shaking extends from quake sources. Colors show the levels of horizontal shaking that have a 1-in-10 chance of being exceeded in a 50-year period. Shaking is expressed as a percentage of g (g is the gravitational acceleration of a falling object). Although strong earthquakes occur less frequently in the eastern United States, damage in this area could be catastrophic in a powerful quake because buildings and other structures have not been designed to withstand severe earth shaking. Damage to buildings, dams, highways, power lines, and similar structures only partly depend on the amount of energy released during an earthquake. Certain kinds of earth materials enhance the effects of earthquake vibrations. In Alabama, structures built on thick, loose sediments of river floodplains and filled areas are more likely to be damaged than structures built on bedrock. In fact, seismic intensity may increase as much as one full unit on the Modified Mercalli Intensity Scale if loose sediments are present. Also, loose sediments with a high moisture content can turn to liquid when shaken.

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