# Understanding The Richter Scale

The Richter Scale

The now-famous Richter scale was developed in 1935 by Charles Richter of the California Institute of Technology. The scale was intended only for use in California to separate the large number of small earthquakes from the small number of larger ones. The scale is derived from astronomy’s stellar magnitude scale.

The scale assigns a number to quantify the size of the earthquake. The number is derived by calculating the logarithm of the combined horizontal amplitude of the largest displacement from zero on a seismogram. It is a logarithmic scale, so an earthquake of five is ten times greater than a four, and an eight is 10,000 times greater than a four.

The energy of the earthquake is proportional to the square root of the cube of the amplitude. So each step of of the scale has an energy 31.6 times that of the previous. A nine, therefore, has 10,000 times the amplitude of a five, but a million times more energy.

Originally posted 2015-01-05 02:18:28.

# Worst Earthquakes Worldwide by Magnitude

Largest Earthquakes Worldwide
In Terms of Magnitude

1.
Chile
May 22, 1960
Magnitude: 9.5

2.
March 28, 1964
Magnitude: 9.2

3.
Aleutian Islands
March 9, 1957
Magnitude: 9.1

4.
Kamchatka, Russia
Nov. 4, 1952
Magnitude: 9.0

5.
Sumatra, Indonesia
Dec. 26, 2004
Magnitude: 9.0

6.
Japan
March 11, 2011
Magnitude: 8.9

7.
Jan. 31, 1906
Magnitude: 8.8

Chile
February 27, 2010
Magnitude: 8.8

8.
Aleutian Islands
Feb. 4, 1965
Magnitude: 8.7

9.
Sumatra, Indonesia
March 28, 2005
Magnitude: 8.7

10.
India-China border
Aug. 15, 1950
Magnitude: 8.6

11.
Kamchatka, Russia
Feb. 3, 1923
Magnitude: 8.5

Originally posted 2015-01-05 02:15:36.

The World’s Worst Earthquakes

As measured by the death toll.

The worst earthquakes in history, in terms of the death toll have  occurred in China. In addition to lying along the earthquake prone “ring of fire”, China also has historically had a high population density. This virtually ensure that the highest earthquake casualties will be in China. It also is helpful that the Chinese have long had efficient bureaucracies, which were able to document the casualties as long ago as the 1500s.

1.

Shaanxi Province, China
January 23, 1556
Magnitude: approximately 8
Death Toll: 830,000

2.
Tangshan, China
July 28, 1976
Magnitude: 7.5
Death Toll: 242,000
The casualties in this may have been higher. The Chinese government is thought to have deliberately understated the numbers for political reasons.

3.
Aleppo, Syria
August 9, 1138
Magnitude: ?
Death Toll: 230,000

4.
Haiti
January 12, 2010
Magnitude: 7.0
Death Toll: 222,517

5.
Xining, China
May 22, 1927
Magnitude: 7.9
Death Toll: 200,000

6.
Damghan, Iran
December 22, 1856
Magnitude: unknown
Death Toll: 200,000

7.
Gansu, China
December 16, 1920
Magnitude: 8.6
Death Toll: 200,000

8.
Ardabil, Iran
March 23, 893
Magnitude: ?
Death Toll: 150,000

9.
Kwanto, Japan
September 1, 1923
Magnitude: 8.3
Death Toll 143,000

10.
Ashgabat, Turkmenistan, USSR
October 5, 1948
Magnitude: 7.3
Death Toll: 110,000

11.
Messina, Italy
December 28, 1908
Magnitude: 7.2
Death Toll: 100,000

Originally posted 2015-01-05 02:10:17.