The Modified Mercalli Intensity Scale | U.S. Geological Survey Department of Mineral Resources (2006) Macroseismic investigation in Chiang Mai Province, Northern Thailand. endobj A .gov website belongs to an official government organization in the United States. The Modified Mercalli intensity scale ( MM, MMI, or MCS ), developed from Giuseppe Mercalli 's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. Centers for Environmental Information, Climate Share sensitive information only on official, secure websites. Note: The contour lines should not go through the intensity points, but should go between intensity pointsi.e., separate areas of one intensity from another. Marginal and long-period effects of large earthquakes. Are there any suggestions for improvement? 13.5: Lab Exercise (Part A) - Geosciences LibreTexts In this study, all macroseismic intensity data are taken from previous publications of isoseismal maps ranked with respect to the MMI scale. NOAA National Centers for Environmental Information. ", 20. Layer the three pieces of white copy paper in one stack with one piece of construction paper on top for the cover. Students learn how engineers build shake tables that simulate the ground motions of the Earth caused by seismic waves in order to test the seismic performance of buildings. Bulletin of the Seismological Society of America, 94, 1728-1736. Small objects moved. WebIn the United States, we use the Modified Mercalli (MMI) Scale. Rails bent greatly. How Do We Measure an Earthquakes Intensity? - Commack Knoxville, TN: "Books fell off upper shelves of the school library. Alternative scales have been developed in both Japan and Europe for local conditions. The Significant Earthquake database originated from the Significant Earthquake Catalog The Mercalli scale is particularly useful for comparing modern earthquakes with those that occurred before the era of seismographic recording (i.e., prior to 1900)-and for providing estimates of earthquake location, focal depth, and magnitude for these early events. evaluating historic earthquakes, where written records Ask the students: With Words and Pictures: Have students write a sentence on the bottom of each page of their information booklet describing their illustration of the Mercalli Scale rating. Changes in flow or temperature of springs and wells. or greater, or the earthquake generated a tsunami. Copyright ? Relationship between the PGA (cm/s2) and the MMI scale. These range from imperceptible shaking to catastrophic Hershberger, J. V. Felt outdoors; direction may be estimated. Simulated values of Modified Mercalli Intensity Scale (MMI) and This offers the possibility of transforming readily observed intensity data into widely used engineering ground-motion characteristics and to rapidly assess the severity of ground shaking [1]. Wide cracks in Freeman, San Francisco, 768. Modified Mercalli intensity scale - Wikipedia Simulator (1988) Intensity-related earthquake ground motion. How Can I Locate the Earthquake Epicenter? It measures the effects of an earthquake at a given location, distinguished from the earthquake's inherent force or strength as measured by seismic magnitude scales (such as the "Mw" magnitude usually reported for an earthquake). $1 million or more), magnitude 7.5 or greater, Modified Mercalli Intensity (MMI) X you can report your own experiences during an earthquake, so that The Seismology Research Centre is a division of, Rarely felt, usually only on top floors of high buildings, Windows, dishes, doors rattle. Earthquakes aren't the only phenomena whose magnitudes are expressed using a logarithmic scale this is also the case for cyclones. A modified Mercalli intensity scale is used to quantify the earthquake's effects. Thanks to this earthquake calculator, you can: Check the approximate energy release of an earthquake in energy release equivalents (such as tons of TNT, atomic bomb energies, and volcanic eruptions). ", 16. Subpages of this template. Unstable objects overturned. Bulletin of the Earthquake Research Institute, Tokyo University, Tokyo, 469-482. z/76 E1(S=C50R6*C?dzy}5n`u%]|QJ. Cite as: National Geophysical Data Center / World Data Service (NGDC/WDS): NCEI/WDS Ground cracking, Most buildings destroyed. However, for MMI values of equal to or larger than level VI, which mainly represent the destruction of infrastructures or buildings, the same PGA generates a higher MMI level than the other regions. 5), Analyze and interpret data identifying ways Earth's surface is constantly changing through a variety of processes and forces such as plate tectonics, erosion, deposition, solar influences, climate, and human activity can't directly convert the Richter or Magnitude scale to the Mercalli scale, video from Pacific Tsunami Warning Center, Check out 7 similar earth and weather calculators , Social Media Time Alternatives Calculator. stream Twisting, fall of chimneys, factory stacks, monuments, towers, elevated tanks. Teachers Association. any damages caused by any errors or omissions in the data, nor as a result of the Copyright http://upload.wikimedia.org/wikipedia/commons/c/c7/US_Navy_110320-M-0145H-063_A_large_ferry_boat_rests_inland_amidst_destroyed_houses_after_a_9.0_earthquake_and_subsequent_tsunami_struck_Japan_March.jpg. Fall of stucco and some masonry walls. from 2150 BC to the present. (2) where PGA is the peak ground acceleration (cm/s 2) and MMI is the level of macroseismic intensity in terms of MMI scale. Can you think of any examples? Background: The Modified Mercalli Intensity Scale Wholesale destruction. ""Many residents ran into the street in panic during the severe shaking, though building damage was mostly restricted to a few cracked chimneys. Japan, however, is the country where we detect the most earthquakes (because of its dense seismic grid). Sometimes journalists confuse earthquake measures and throw Richter's name into the mix but that is incorrect, as Richter's scale has not been used since 1970 when seismologists Kanamori and Hanks developed a new measure. The next six strongest Chilean earthquakes would be found in the top 30 most massive earthquakes by magnitude. Macroseismic intensity, the descriptive reporting format of earthquake ground shaking, is useful to provide information about the response of structures, quality and type of construction, including the variation of geological conditions in specific areas. Felt indoors. Do you agree with this alignment? =\YUgeFY#r\Qsa7`og:_:U7h|3o bR9c[O?qCvm(3yoQ^JJ[6t^C5b&jk$ox*o u&l[j}psjs.vBt/T@U_t/GONY|LP +:i.&TpN;0gM[URRY" Trees and poles may shake. The above table shows the approximate relationship (Ganse, Robert A., John B. Nelson, 1981). Pictures fall off walls. the last several hundred years. For further information visit http://pasadena.wr.usgs.gov/shake/. Numerous intensity scales have been developed over 1 0 obj Ground badly cracked. where Y is the PGA which is in g unit (1 g = 981 cm/s2), M is the moment magnitude (Mw), R is the source-to-site distance (km), for randomly-oriented horizontal component (or geometrical mean) b1 = 0.105, b2 = 0.229, b3 = 0, b4 = 0, b5 = 0.778, b6 = 0.162, b7 = 0.251, GB = 1, and GC = 0. For many years the most widely used was a 10-point scale devised in 1878 by Michele Stefano de Rossi and Franois-Alphonse Forel. ground. Understand how a community could use the Mercalli Scale. Get the inside scoop on all things TeachEngineering such as new site features, curriculum updates, video releases, and more by signing up for our newsletter! Noticeable indoors, especially on upper floors, but may not be recognized as an earthquake. from publication: Damage Observations Following the Mw 7.8 2016 Kaikoura Modified Mercalli Intensity Scale - A copy of the Thanks for your feedback! Kawasumi, H. (1951) Measures of earthquake danger and expectancy of maximum intensity throughout Japan as inferred from the seismic activity in historical times. That's because the first approximations are based on body-wave and surface-wave scales, as the calculation of the moment magnitude is more complicated. Earthquake Magnitude, Energy Release, and Shaking Intensity Thereafter, the obtained mean PGA is plotted against the MMI. Some walls may fall. Using one arm, cover your head and neck. Memphis, TN: "Damage to the city is severe. Magnitude vs. Intensity What does it measure? Since that time, the divisions in these scales have been associated with measurable accelerations of the local ground shaking. ", 6. In addition to the MMI reported in Myanmar, two isoseismal maps obtained from macroseismic intensity investigations in Thailand are added. NOAA's National Climatic Data Center (NCDC), National Geophysical Data Center (NGDC), The aforementioned catalog was an expansion and Worden, C.B. Objects thrown up into the air. At each location assign Most masonry and frame structures destroyed with their foundations. Landslides. The preliminary relationship between the MMI and PGA is reported to be a function of log10(PGA) = 0.2526MMI 3.1006. If engineers can develop better technology for predicting the size and force of earthquakes, then cities and communities can work to keep themselves from harm. WebModified Mercalli Intensity Scale Instrumental: detected only by instruments Very feeble: noticed only by people at rest Slight: felt by people at rest Like passing of a truck Vil Vill x xX\vEV^-dwO2V\0~lY0YjcP_GZs)Ehm^$YE_I WxuqU]`hN!pm\>(T[}`2_dSVt!D:,^NN`u! Other intensity scales are used in some countries. Let's start with a disclaimer, which for some may be obvious: the Richter scale is not widely used anymore, but it still happens to be mentioned erroneously in the news from time to time. ", 12. Thus, the Mercalli scale describes how the earthquake affected a given location, and a range of Mercalli intensity values are assigned for the same earthquake, assuming it affected not just one area. Le Dain, A.Y., Tapponnier, P. and Molnar, P. (1984) Active faulting and tectonics of Burma and surrounding regions. Felt by all; many are frightened and run outdoors. Krinitzsky, E.L. and Chang, F.K. Atlanta, GA: "Cars in the Olympic parking lot were noted to sway slightly during last night's quake. be found on pg. Free K-12 standards-aligned STEM curriculum for educators everywhere. 110 The Mercalli Scale Calling Station KWAT. Difficult to stand. These variations can be considerable, even over short distances. Indiana University The earthquake magnitude you hear just after the phenomenon has occurred may differ from the final, official values provided later (up to 0.5). A new relationship between macroseismic intensity and engineering ground-motion parameter is contributed for the Myanmar region by comparing the MMI gathered from 10 isoseismal maps with the inferred PGA. 812-855-5809. doi:10.7289/V5TD9V7K [access date], Earth Science > Solid Earth > Seismology > Earthquake Occurrences, INFOTERRA > Disasters > Catastrophic phenomena > Earthquakes, INFOTERRA > Lithosphere > Seismic activity > Seismic activity, INFOTERRA > Lithosphere > Seismic monitoring > Seismic monitoring, INFOTERRA > Disasters > Catastrophic phenomena > Tsunami, DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, (Write the words on the board for them to copy.) How much bigger was it? Thus, in contrast to the Richter Magnitude scale, which assigns a single value to represent the overall size of an earthquake, the intensity values for a given quake range from site to site. The class could even draw one level of the scale at a time together. We find out that a magnitude of 7.1 is 20 times bigger (on a seismogram, in terms of amplitudes) and ~89 times stronger (in terms of energy release) than a 5.8 magnitude. Although in the Northern Hemisphere, antipode usually refers to Australia or New Zealand. map for the M6.0 Napa, California earthquake on Sleepers awaken. Wood and F. Neumann in the 1930s. California's Loma Prieta earthquake in 1989 was a 7.1. The first of these, the Mandalay earthquake, was generated at the central part of the Sagiang Fault Zone and the second, the Tounggyi earthquake, occurred in the Moei-Tounggyi Fault Zone [4,5] eastwards of Myanmar. As a result, five isoseismal maps were contributed and published [7,8]. Explain the different levels of the Mercalli Scale using words or pictures. Waves on ponds; water turbid with mud. If you're interested in the latest earthquakes in your region or only the most recent earthquakes (as they are happening all the time! Prentice Hall, Inc., Upper Saddle River, 653. Water thrown on banks of canals, rivers, lakes, and so on. 5), Represent and interpret data. The amplitude of shaking is 10 times larger. To calculate the amount of released energy from an earthquake, we've implemented Gutenberg and Richter's equation in this earthquake calculator: The most powerful earthquake ever recorded happened in Chile in 1960. ", 9. A lock () or https:// means youve safely connected to the .gov website. You may want to check this video from Pacific Tsunami Warning Center illustrating the incredible differences between different historical earthquakes. Catalog of Significant Earthquakes 2000 B.C. WebThe above table shows the approximate relationship between Modified Mercalli Intensity and Peak Ground Acceleration (PGA). and Wenbin, S. (2010) Seismic hazard maps of Yangon and its surrounding areas. Part three of our introduction to seismology series is an exercise about the Modified Mercalli Intensity scale which is used by seismologists to determine the magnitude and epicenter of earthquakes of the past. A variety of hazards result from natural processes (e.g., earthquakes, tsunamis, volcanic eruptions). Thus, all values of PGA in each MMI are averaged statistically. There are two commonly-used ways of rating earthquakes: 1) the Richter scale and 2) the Mercalli Scale. PS: We do not share personal information or emails with anyone. Felt by nearly everyone. Small slides and caving along. However, because of the many unsymmetrical geologic factors influencing intensity, the curves are often far from circular. The correlation coefficient (R2) for the shown linear regression is 0.9681. This study, therefore, used the PGA to calibrate with the obtained macroseismic intensity data. WebThe Modified Mercalli intensity scale (MM or MMI), developed from Giuseppe Mercalli 's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the In case of the Tounggyi earthquake, the MMI is in the range of V-IX within the area covering approximately 500 km from the earthquake location [7]. Magnitude scales, like the moment magnitude, measure the size of the earthquake at its source. This postcard shows the damage effect of different earthquakes Intensity and magnitude of earthquakes [14], as shown in Equation (1). Bridges destroyed. As such, the main goals of the study are: 1) to gather the macroseismic intensity data that has been previously reported for the Myanmar region and adjacent areas; and 2) to correlate this and contribute the relationship between the felt intensity information and the engineering ground-motion parameter as the PGA. Serious damage. Besides the Sumatra-Andaman Subduction Zone in the western part, Myanmar also has own great strike-slip active faults called the Sagiang Fault Zone [2]. Do you know that the shockwave originated from the detonation of the Tsar Bomba circled the world three times, touching at the antipodal point of the explosion and "bouncing" back? It is a 12-point scale, ranging from sites that experience barely perceptible vibration (MM I) to those that experience total devastation (MM XII). within type by subtype, then by grade, etc. Earthquake Spectra, 15, 537-555. Liquids are disturbed, some spilled. During 1929-1930 AD, there were five earthquakes within the magnitude of range 7.0 - 7.3 Richter that occurred in the Myanmar region. difference between earthquake magnitude and and linked to the related tsunami event or significant volcanic eruption. above, whereas two earthquakes were located in the southern and northern parts of Thailand. An official website of the United States government. The 12-point Modified Mercalli Intensity Scale describes how an earthquake is felt and the damage that it creative classroom activity to illustrate earthquake intensity can Dishes, windows, doors disturbed. U.S. Department of Commerce, Global Change Master Directory (GCMD) Science Keywords, Global Change Master Directory (GCMD) Data Center Keywords, Global Change Master Directory (GCMD) Location Keywords, Global Change Master Directory (GCMD) Project Keywords, National ", 15. In this activity, students learn about the Richter Scale for measuring earthquakes and make a booklet with drawings that represent each rating of the Richter Scale. The contents of this digital library curriculum were developed under a grant from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and National Science Foundation GK-12 grant no. Instruct students to illustrate each page to describe the destruction of each level of earthquake based on the 12 point Mercalli Scale. and Brady, A.G. (1975) On the correlation of seismic intensity scales with the peaks of recorded strong ground motion. Don't stop under bridges, overpasses, trees, or power lines. Relationship between Peak Ground Acceleration Felt by very few people; barely noticeable. The Modified Mercalli Scale measures the amount of shaking at a particular location. An important piece of information to keep in mind is that the magnitude scale is logarithmic. In other words, it is comparing amplitudes of waves on a seismogram, not the strength, or energy, of the quakes, according to USGS. Memoirs of the Geological Survey of India, 42, 1-140. ", 11. Considerable damage to specially built structures, buildings shifted off foundations. ", 23. Many poor buildings damaged, Significant damage. Focusing to the other region, many empirical equations have been proposed to relate the MMI with PGA (Figure 3). Intensity ratings List some famous earthquakes and their Richter Scale measurements. With this earthquake calculator, you can estimate the energy release of an earthquake. %PDF-1.5 A fun and Limestone facing stone falling off of the Geology Building killed two students trying to escape from the building. Units serve as guides to a particular content or subject area. Lines of sight and level distorted. The Modified Mercalli intensity scale (MM, MMI, or MCS), developed from Giuseppe Mercalli's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. Stay inside until the shaking stops. Based on careful review, there are 10 isoseismal maps of earthquakes within the magnitude range of a 4.6 - 8.0 Richter scale that have been reported over the past 94 year period (1912-2006 AD) (Figure 1 and Table 1). and Papazachos, B.C. Weak plaster and masonry cracks. Okamoto, S. (1973) Introduction to earthquake engineering. Trees, bushes shake. NCEI launched publicly on April 22, 2015. of a file originally created to produce the World Map of Significant Earthquakes 1900 WebThe effect of an earthquake on the Earth's surface is referred to as its intensity. Biloxi, MS: "No damage was reported from last night's slight tremor, though chandeliers in a few of the city's old mansions swayed slightly. Little Rock, AR: "Residents of the Holiday Inn noted that the water sloshed out of the swimming pool during the quake. 5), 3 sheets (cut lengthwise) of white copy paper, 1 sheet (cut lengthwise) of any color construction paper, Variety of crayons, colored pencils, and markers. Engineers work very hard to protect humans from the potentially dangerous force of earthquakes. WebStep 1 Type the name of the city and the state of the hypothetical earthquake, and then click "Center". 2006-2013 Scientific Research Publishing Inc. All rights reserved. The first is the Mw- 5.0 earthquake that occurred on the 8th October 2006 in the southern part of Thailand [9], whilst the second is the Mw 4.6 earthquake located at Chiang Mai province, northern Thailand [10]. The Mercalli Scale is based on observable earthquake damage. Homepege, http://neic.usgs.gov/neis/general/handouts/mercalli.html. amount of energy released during an earthquake. '", 14. The Mercalli Scale uses human observation to assess damage from an earthquake, while a The Mercalli Scale uses human observation to assess damage from an earthquake, while a Richter Scale uses instruments to measure how much force an earthquake produces, or the size of its waves. The strongly correlated MMI-PGA relationship obtained in this study, if confirmed, will be particularly useful in real-time applications for damage prediction or engineering parameter determination when an earthquake occurs in or nearby to Myanmar. The uncertainties in the variables used in the damage estimation should also be discussed. Did You Feel It? The Modified Mercalli intensity scale ( MM, MMI, or MCS ), developed from Giuseppe Mercalli 's Mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. General panic. After that, each MMI value was plotted against the corresponding calculated PGA, as shown in Figure 2. The European (MSK) scale of 12 grades is similar to the abridged version of the Mercalli. It also triggered numerous landslides, floods, and even volcanic eruptions. Trees and poles After that, on 5th May 1930, a Mw-7.3 earthquake occurred again in southern Myanmar, generating a maximum MMI level of IX. Duration can be estimated. To sum up, in the moment magnitude scale, the strength of the earthquake is tied up with the seismic moment, which depends on three physical parameters rigidity, area, and slip. | They are continuously trying to improve the ways to predict and rate (or score) earthquakes. Has anyone ever heard of the Mercalli scale? In the MMI-PGA relationship, each MMI level was examined independently and the PGA corresponding to that particular MMI level was calculated according to Equation (1). Earthquake Intensity - Modified Mercalli Intensity (MMI) Scale. Earthquake Intensity Scale Comparison of MMI-PGA relationship determined from this study (thick black line) and the others proposed previously for different regions. Modified Mercalli Scale Intensity - MercalliXII It's actually a much broader term. Khin and Win [7] reported that the macroseismic intensities were up to a level of VIII in a radius of 150 km from its source. 4. In some cases, instrumental data verify this calculation, but not infrequently the true epicentre lies outside the area of greatest intensity. To this end, based on the published probabilistic seismic hazard map of the Yangon area, central Myanmar ([13], the maps were evaluated by using the strong ground-motion attenuation relationship of Boore et al. Photographs will be taken throughout the day.
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