Richter Scale Range

Any given earthquake, may it be a small one that cannot be even felt or a large one that practically shakes half the tectonic plates, releases a form of energy that is known as the tectonic energy. This energy is released in the form of enormous waves, which are known as Seismic waves, that go out from the focus, hypo-center of the earthquake (not to be confused with epicenter which is the point of earth that is directly above the focus). These waves are the ones that destroy the human settlement or practically anything that lies in their path. The amount of destruction is directly in relation to the intensity or rather the magnitude of the waves. Thus, measuring the seismic waves with the help of a seismograph and comparing it with the values of Richter scale can prove to be very much effective in providing rescue and remedy for the affected region.

Richter Scale Explained

Before we study the formula of Richter scale, let us have a look at the logic of the formula and how the Richter scale works. The Richter magnitude scale was developed by Charles Richter, an American geophysicist. The scale is basically an algorithm of the amplitude or severity of the earthquake. It basically means that a level 6 earthquake has a wave amplitude that is 10 times greater than an earthquake of level 5. The logic is pretty complex to figure out, and the basic principle is that a 10 fold increase is seen when the level increases. The Richter scale formula works as follows...

M_L = Log₁₀A - Log₁₀A₀(δ)

Where,
A=maximum excursion of seismograph
A₀ and (δ) = distance between the epicenter and place there the seismograph is located
M_L = Richter Scale Range

Range of Richter Scale
The Richter scale in accordance with the Wood-Anderson torsion seismometer, ranges from 0 to 10 though conventionally only tremors from 2 to 9 have been recorded in history. The following table will give you an idea of the tremors that lie in the Richter scale ranges.

Richter Scale Magnitudes

Richter Magnitude	Description	Effects and Comparable Examples	Comparable Joules	Occurrence
- 2.0 Micro	Micro	not felt	63.1 kJ to 63.1 MJ	8,000 per day
2.0-2.9	Minor	not felt sometimes recorded, equivalent to small bombs that range from hand grenade to air blast bomb	63.1 MJ to 2.00 GJ	1,000 per day
3.0-3.9	Minor	felt, small atomic bomb	2.00 GJ to 63.1 GJ	49,000 per year
4.0-4.9	Light	noticeable, Small atomic bomb	63.1 GJ to 2.00 TJ	6,200 per year
5.0-5.9	Moderate	major damage, Nagasaki atom bomb	2.00 TJ to 63.1 TJ	800 per year
6.0-6.9	Strong	destructive, Java earthquake 2009	63.1 TJ to 2.00 PJ	120 per year
7.0-7.9	Major	serious damage, Kashmir earthquake 2005	2.00 PJ to 63.1 PJ	18 per year
8.0-8.9	Great	serious damage, Sumatra earthquake, 2007	63.1 PJ to 2.00 EJ	1 per year
9.0-9.9	Great	devastating	2.00 EJ to 63.1 EJ	1 per 20 years
10.0 and above	Epic	unknown	15.0 gigatons	God Forbid!

It must be noted that the largest earthquake ever recorded was of 9.5 and it occurred in Chile. Another excellent article titled Richter scale for kids explains the concept in a simplified manner. Another competing scale is the Mercalli scale which is basically based upon the observations of destruction.