How is the Richter scale used?
Nov 16, 2009
in
Earthquake Questions
I need help:
Explain how the Richter scale is used and then tell what the disadvantage is to using this scale.
I don’t have any books to find this information and nothing else.
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6 comments
thegeologist on November 16, 2009 at 7:00 pm
The Richter Scale is used to determine the amount of energy released during an earthquake. The Modified Mercalli Intensity Scale is used to measure the amount of damage done.
For every whole number increase in the scale there is a 10-fold increase in the amount of shaking, but a 31-fold increase in the amount of energy released. A magnitude 5 earthquake releases 31 times more energy than a magnitude 4, and about 1,000 times more energy (31 x 31) than a magnitude 3!
It is useful for engineers that need to develop more earthquake resistant structures.
One disadvantage to the Richter Scale is that the calculation itself doesn’t work well for large earthquakes. Instead, seismologists use the Moment Magnitude Scale for large quakes, although the numbers are typically reported as Richter magnitudes.
kevinkm77 on November 16, 2009 at 7:00 pm
how strong an earthquake is. every increase by 1 on the richter=10x more destructive than the last number it increased from
evildoer86d on November 16, 2009 at 7:00 pm
That link below explains it. I have never heard of any problems with the scale but their is one –it gets shaken in the quake if it close enough, that cant help with accuracy
Turbidite on November 16, 2009 at 7:00 pm
The output of the richter scale is the log of the amount of energy in an earthquake. So 4 is 10 times stronger than 3 and 1/10 the strenght of a 5.
estemenm on November 16, 2009 at 7:00 pm
Before Richter, (Charles Francis), science used Mercalli scale, becouse whenever there was a sism, scientist had to travel, say, from Tokio or Berlin to Perú, or México, to investigate the consecuences of that particular quake. Once they arrived, (months later), all they could do is ask people how it felt, how builings were damaged, how animals behaved etc.
Sismographers instruments were then invented, they registed the movments of earth in a paper. This graphics show that there are 2 main vibrations (primary and secondary, they call them), that travel diferent ways and at diferent speeds, so in a given place, away from the place where the quake originated, paper registers one graphic for some time, and a larger, wider graph for the "second" wave that arrives later.
Mr. Richter scale permits to know, measuring width and length of the graphs in paper, how distant the quake originated, but does not tell in which direction, so sismolgist have to wait for the report of at least two more station, in order to triangulate the place of origin.
This scale, of course, does not tell how many damages the quake made, becouse could be the case that it occurred in a not populated area, or in the botton of an ocean.
For this reason, Mr. Richter borrowed the term MAGNITUDE from astronomy, since, as in star watching, the information that arrives to any station is a relative one, but it is very important to determine the amount of energy released and locate the point of origin.
I notice that scientist, in order to determine the damages of areas affected by quakes, use in these days what they call Mercalli modified scale. pardon my english, my native idiom is spanish, I live in a very sismic zone, in Colima, México. Best regards
Esteban estemenfer@hotmail.com
Here you can learn more:http://es.wikipedia.org/wiki/Charles_Richter
A.Ganapathy India on November 16, 2009 at 7:00 pm
Mr Charles Richter found a method in 1935 to calculate the energy released from earthquakes from the origin point called focus. A seismograph that records the arrival time of different earthquake waves and time amplitude,and frequencies are recorded in that instrument. Because of the difference in speed between Primary wave and secondary wave when you record it from the place other than at epicenter we can calculate the distance of epicenter. The shaking is getting increased by ten times for each Richter scale and reduced by inverse square of the distance. These data’s are used for the calculation of Richter scale.To find the epicenter we need three such picture from three direction. The Richter scale releases about 31.7 times more energy for each scale. Here is the energy release chart. It disadvantages are it is not directly connected with destruct ions,the measuring method gives different results from different place and it is better to take average for accurate measurement.
Approximate TNT (Tri nitro telecom ) Yield for Seismic Energy
Richter scale
1 30 lbs
2. 1 ton
3.29 ton
4.1000 ton
5.32000 ton
6.1 million ton
7.32 million ton
8.1 billion ton
9.32 billion ton
101 trillion ton.
The more meaningfull scale is Mercalli scale unfortunatly not in wide use.