As you can see here, as the numbers get higher, the more you feel the shaking. Students study the mercalli scale and analyze how it is used to rate earthquakes. The preliminary relationship be tween the mmi and pga is reported to be a function of log. Intensity is different than the magnitude in that it is based on observations of the effects and damage of an earthquake, not on scientific measurements. The modified mercalli intensity scale sandiegocounty. This means that an earthquake may have different intensities from place to place, but it will only have one magnitude. Intensity scales, like the modified mercalli scale and the rossiforel scale, measure the amount of shaking at a particular location. However, the amount of shaking experienced at different locations varies based on not only that overall magnitude, how far you. Intensity and intensity scales gfzpublic gfzpotsdam. Handout primarily discussing the modified mercalli scale.
For students to draw isoseismals on a map that includes mercalli intensity data. The modified mercalli intensity scale mmi, developed in 1931, is the most. Earthquake zones find out more about earthquake zones that outline tectonic plate boundaries where plates are coming together, moving apart and slipping past each other. Find mercalli scale stock images in hd and millions of other royaltyfree stock photos, illustrations and vectors in the shutterstock collection. Thousands of new, highquality pictures added every day. The mercalli scale is a rather arbitrary set of definitions based upon what people in the area feel, and their observations of damage to buildings around them.
Some intensity scales in the past, such as the modified mercalli scale in its 1956. The modified mercalli scale of earthquake intensity and. Ting the mercalli intensity scale through lived experience s hortly after almost any perceptible earthquake, the news reports the magnitude of the event based on the richter scale. Unlike with the richter scale, the mercalli scale does not take into account energy of an earthquake directly. It measures the shaking you feel during an earthquake. This value is quick and simple to communicate over the air and equates to an objective. Modified mercalli scale intensity effects pga gals i not felt.
The modified mercalli intensity value assigned to a specific site after an earthquake has a more meaningful measure of severity to the nonscientist than the magnitude because intensity refers to the effects actually experienced at that place. The modified mercalli intensity scale simplified, from reference. The scale is known today as the modified mercalli scale mm or modified. Mercalli scale measures intensity kids earth science. Today, we are going to look at the mercalli scale s damage rating and create a booklet to help inform citizens of potential danger. The modified mercalli intensity scale mm or mmi, descended 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. Display the modified mercalli scale on the overhead projector. An additional 54 questionnaires were sent to police and firestations within 25 km of the epicenter. None of them is suitable for use in all countries, and it may be considered a merit of kawasumis scale that it contains explicit reference.
Modified mercalli scale intensity effects pgagals i not felt. Modified mercalli intensity scale mmi abag resilience. The modified mercalli intensity or mmi was based in part on postal questionnaires, in which respondents summarize the effects of shaking in their communities. The strength of an earthquake is usually measured on one of two scales, the modified mercalli scale and the richter scale. It was developed in 1931 by the american seismologists harry wood and frank neumann. Mercalli scale smithsonian science for the classroom. Remember, contours are lines that separate points of greater value on one side. Pdf recent studies of the effects and modified mercalli mm. The scale was improved by mercalli, who published a modified version, still with ten degrees. The modified mercalli intensity scale describes the amount and type of damage caused by an earthquake on a scale from i to xii.
Mercalli scale find out about the mercalli scale that measures the intensity of an earthquake rather than its magnitude. Just download a template, open it in a pdf reader, and print it. This video explains the mercalli intensity scale, a subjective scale that describes different levels of shaking and damage caused by earthquakes. Modified mercalli intensity scale branch of earthquake and geomagnetic information, u. What is the difference between magnitude and intensity. The mercalli scale is a rather set of definitions based upon what people in the area feel, and their observations of damage to buildings around them the scale goes from 1 to 12, i to xll or using the descriptive titles. In cases where it is possible to draw isoseismals for intensities 6 and 7, one should. These printable tip sheets are available in pdf format. Richters version became instead the modified mercalli scale of 1956. The formation of a satisfactory earthquake intensity scale. Have you ever wondered about who invented the mercalli intensity scale. Revisions in this version of the scale are shown in italics. They construct a booklet with drawings that represent each rating of the scale.
The 1873 version of the rossiforel scale used in figure 2 had 10 intensity levels. Helps students understnad difference between magnitude and intensity. Pdf implementing a spatial analysis of modified mercalli. The relationship between richter magnitude and modified.
He had also published an earlier scale of six degrees which was a. The most widely used intensity scale, the modified mercalli scale, is divided into 12 degrees, each identified by a roman numeral. After every earthquake regardless of intensity the maps are checked and only after survey work is an accurate idea provided of the effect. What are some advantages and disadvantages of the richter. Although qualitative in nature, it can provide a more concrete model for middle and high school students striving to understand the dynamics of earthquake behavior. The modified mercalli intensity scale, descended from giuseppe mercallis mercalli intensity scale of 1902, is a seismic intensity scale used for measuring the intensity of shaking produced by an earthquake. An earthquake causes many different intensities of shaking in the area of the epicenter where it occurs. Relationship between modified mercalli intensity and peak. Of existing intensity scales, the sieberg scale, the 1956 version of the modified mercalli scale, and kawasumis 1951 scale are the most satisfactory. Modified mercalli intensities for nine earthquakes in central and. This scale, composed of increasing levels of intensity that range from imperceptible shaking to. Although numerous intensity scales have been developed over the last several hundred years to evaluate the effects of earthquakes, the one currently used in the united states is the modified mercalli mm intensity scale. Be sure you have an application to open this file type before downloading.
These criteria have been adopted in an international intensity scale for environmental effects. Modified mercalli intensity scale of 1931 the formation of. Some intensity scales in the past, such as the modified mercalli scale in its. Pdf the modified mercalli intensity scale revisions. Drawing contours should be familiar to students who have. Modified mercalli scale uwi seismic research centre. The modified mercalli mm intensity scale is composed of 12 increasing levels of intensity that range from imperceptible shaking to catastrophic destruction and is designated by roman numerals i through xii.
They complete map work and write a first hand account of a person living in each level of intensity on the modified mercalli scale. Modified mercalli intensity scale mmi the modified mercalli intensity mmi estimates the intensity of shaking from an earthquake at a specific location or over a specific area by considering its effects on people, objects, and buildings. Modified mercalli intensities for nine earthquakes in. 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. Watch this video, and you will be an expert on it all. This was the first scale to be widely used internationally. Investigating the mercalli intensity scale through lived.
However, the two terms are quite different, and they are often confused. Extracts from the new zealand version of th e modified mercalli scale relating to chim ney damage dowrick, 1996. Compare the effects of the earthquake to the modified mercalli intensity scale table 1 and assign an intensity value to each location in table 2. Instead of using vague and subjective descriptions like major, minor or heavy, a mikemike value is reported. It measures the effects of an earthquake at a given location, distinguished from the earthquakes inherent force or. Modifiedmercalliintensityscale earthquakedamagereporting byjohnjacobschmidt,amrron intheimmediateaftermathofanearthquake,searchandrecoveryeffortswill. The lower numbers of the intensity scale generally deal with the manner in which the earthquake is felt. The intensity of the modified mercalli scale always stopped at xii anything higher as you claim is someones idea of or lack of comprehending what total destruction means. Modified mercalli intensity values for the january 12, 2010, earthquake in haiti are represented on the haiti earthquake intensity map. The effect of an earthquake on the earths surface is called the intensity.
Implementing a spatial analysis of modified mercalli intensity zones and population in indonesia. The modified mercalli intensity scale of 1931 is the basis for the u. If this table is garbled, try the plain text version. The two of them then combined their efforts and produced a joint scale, the rossiforel scale, with ten degrees of intensity. An earthquake has a single magnitude that indicates the overall size and energy released by the earthquake. Geological survey, sent out 610 mail questionnaires to postoffices situated within 600 km of the earthquake epicenter. Modified ivfercalli intensity scale of 1931 277 modified mercalli intensity scale of 1931 by harry o. Wood and frank neumann the formation of a satisfactory earthquake intensity scale has long been a subject for consideration and discussion among those who are in terested actively in studies of shock intensity and its geographic mani festation. So the intensity of an earthquake will vary depending on where you are.
Modified mercalli intensity scale mmi the modified mercalli intensity mmi scale depicts shaking severity. Mercalli intensity scale simple english wikipedia, the. Mercalli scale illustrated activity teachengineering. While this measure is specific and has deep meaning to most seismologists, the public has very little understanding of how this exponential energy measurement. For united states earthquakes, intensities are assigned on the basis of the modified mercalli intensity mmi scale wood and neumann, 1931.
They study why engineers develop rating scales for earthquakes. Modified mercalli intensity scale what is our evidence that we live on a changing earth. The intensity of an earthquake is listed along with effects on the modified mercalli scale in this printable guide. In santa clara county aresraces, we use the modified mercalli intensity scale for efficient and standardized reporting of earthquake damage. Find mercalli scale lesson plans and teaching resources.
The mercalli intensity scale or more precisely the modified mercalli intensity scale is a scale to measure the intensity of earthquakes. Pdf the modified mercalli intensity scale revisions arising from. For example, an earthquake intense enough to be felt by a person standing nearby is said to have an intensity of mm iii. Modified mercalli intensity scale for additional information on statistics on percentage of uninhabitable residential units by construction type and mmi level, click here. In new zealand, where earthquakes occur from near the surface right down to a depth of over 600 km, the modified mercalli intensity scale is a better indicator of an earthquakes effects on. Modified mercalli intensity scale of 1931, as originally abridged by wood and neumann.
Modified mercalli scale after richter richter, 1958. Plot the intensity values on the following map and contour the data. Mmi value description of shaking severity summary damage description used on 1995 maps full description i. Marginal and longperiod effects of large earthquakes.
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