The Richter Scale, also referred to as the Magnitude Scale, measures the size and scope of earthquakes and seismic activity in general. This system of measurement was created by Charles Richter in 1935, at the California Institute of Technology. Since much of the western US state lies on a faultline, the development of an accurate system to measure earthquakes was especially important. The Richter scale was later used to measure seismic activity in other parts of the world.
An earthquake categorized as 2.0 or less on the Richter Scale is usually a very minor tremor and one that may not even be felt by laypeople in the area. Earthquakes listed as 3.0 are usually felt, although they seldom produce any damage. A 4.0 tremor is very noticeable and make cause minor damage, generally in private homes, where items may fall from shelves. Earthquakes listed as 5.0 may cause some buildings to collapse, while anything above 6.0 will result in severe structural damage. An earthquake categorized as 9.0 or above will produce fatal and catastrophic results.
In the beginning, to know about the intensity of earthquake was totally dependent upon the description of the event. However it was a big issue in that sense that description about the event varies from person to person.1902, much reliable scale was introduced by Giuseppe Mercalli .It was based on the amount of damage that happened to different kind of structures.
Later in 1935 Charles Richter tried to attempt the earth quake into large, medium and small magnitudes. The system he developed measured the magnitude of the earthquake as the motion measured by seismic instrument. Today the scale we are using to calculate the magnitude is the modified or refined form of Richter scale to measure the magnitude.
The larger earthquake that ever recorded on Richter magnitude scale was of 8.6.Earth quake larger then the 9 magnitude are very rare to occur and the earthquake that are less then 2,5 Richter magnitude usually do not felt by humans. Richter used logarithmic scale for finding Magnitudes. According to some latest research it is shown that Richter scale doesn't completely differentiate between those earthquakes which have very high magnitudes. Since all of the very strongest earthquakes have almost equal wave amplitude in most cases.
Newspaper reports of earthquakes often indicate their force in terms of numbers on the Richter Scale. These ratings give an indication as to the severity of the quake with increasing severity from 1 through to 8. Running through the numbers 1 to 8 on the Richter Scale, the effects are these: 1 - quake detectable only by seismographic measurement; 2 - hanging objects swing slightly and a few people might feel the tremor; 3 - people indoors feel some vibrations; 4 - buildings tremble and glassware breaks; 5 - furniture overturns and pictures fall from walls; 6 masonry cracks, some houses cave in, windows break and chimneys fall; 7 extensive damage to dams, dikes and bridges, with many buildings collapsing; 8 - all structures receive catastrophic damage.
The earthquake in Peru occurring on May 31, 1970, in which more than 50,000 persons were killed and 800,000 left homeless, measured 7.8 on the Richter Scale.
The Richter scale measures the strength or size of an earthquake. It was devised in 1935 by American seismologist Charles F Richter. Initially it measured earthquakes occurring in California. Later it was modified to measure earthquakes anywhere in the world.
The Richter scale measures the intensity of earthquakes by determining how much the ground shakes 100 km (60 mi) from the earthquake's epicentre, the spot on the earth's surface directly above the earthquake's origin. Scientists used a seismograph to measure the amount of ground movement. So sensitive are seismographs that they can detect movements as small as about 0.00001 mm (about 0.000004 in) to movements as large as about 1m (about 40 in). In the Richter scale earthquakes of magnitude 5 are considered moderate, while of magnitude 6 are considered large and those of magnitude 7 are considered major, and quakes of magnitude 8 or larger are considered devastating. The Los Angeles earthquake of 1994 was of magnitude 6.7 and the San Francisco earthquake of 1906 was of magnitude 7.9. Rarely do the earthquakes of magnitude 8 or greater occur. The Richter scale is not the scale used to measure earthquakes. Currently, the Modified Mercalli Intensity Scale, or MM scale is also widely used.
The scale which is used to measure the magnitude of the energy released during an earthquake is known as Richter scale. This scale is developed by making the values from 0 to 8. This is a logarithmic scale, which means that when there is an increase in each unit on the scale then there will be a corresponding absolute increase by an order of magnitude (factor of 10). On the given link the diagram and the measurements of the Richter scale is given which can help you in making the Richter scale.