+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Deviation of magnitude frequency distribution of earthquakes from the Gutenberg-Richter law; detection of precursory anomalies prior to large earthquakes



Deviation of magnitude frequency distribution of earthquakes from the Gutenberg-Richter law; detection of precursory anomalies prior to large earthquakes



Physics of the Earth and Planetary Interiors: -4, Pages 229-238. 1992.



We present a measure that represents the degree of deviation of the magnitude frequency distribution of earthquakes from the Gutenberg-Richter (GR) law. The magnitude frequency distribution of earthquakes has been considered to obey the GR law. Actual distributions, however, often deviate considerably from this law. Let ni, N, M0 and b be the number of events with magnitude Mi Mi + M, total number of earthquakes, lower limit of the magnitude and b value of the GR formula, respectively. Then the measure of deviation is given using Kullback-Leibler's mean information as C=ip(Xi)ln[p(Xi)q(Xi]Xi=MiM0 where p(Xi) = niN and q(Xi) = b ln 10 exp (b ln 10 Xi). Function q(Xi) denotes the GR distribution and thus this measure gives the degree of deviation of the magnitude distribution from the GR law. When the magnitude distribution of earthquakes fits the GR formula more closely, the ‘C’ value becomes smaller and is zero if the distribution obeys the GR law exactly. Conversely, if the distribution deviates greatly from the GR law, the ‘C’ index shows a large value. We have investigated the temporal variation of ‘C’ values before and after large earthquakes and swarm earthquakes in Japan. Results show considerable variations of ‘C’ values before and after large earthquakes. Prior to large earthquakes, ‘C’ values become small, which indicates that magnitude distributions fit better to the GR law. The ‘C’ indices show drastic change after mainshocks. During swarm earthquakes, the variation of ‘C’ values is rather large, but ‘C’ values are smaller than ordinary earthquakes. In some swarms the ‘C’ indices reach a maximum at the time of the greatest activity. This measure is a useful tool with which to observe the characteristic properties of the seismic activity and may be used for detection of precursory phenomena of large earthquakes.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 018387257

Download citation: RISBibTeXText

DOI: 10.1016/0031-9201(92)90093-b


Related references

Deviation of magnitude frequency distribution of earthquakes from Gutenberg-Richter relation before medium and strong earthquakes in North-West Yunnan, China. Dizhen Yanjiu = Journal of Seismological Research 22(3): 228-234, 1999

Statistical Detection and Characterization of a Deviation from the Gutenberg-Richter Distribution above Magnitude 8. Pure and Applied Geophysics 161(4): 839-864, 2004

Magnitudes of larger earthquakes not included in the Gutenberg-Richter's magnitude catalogue. Tectonophysics 49(3-4): 171-184, 1978

Changes in the magnitude-frequency b-value prior to large (M > 6.0) earthquakes in Japan. Tectonophysics 193(4): 311-325, 1991

A geometric frequency-magnitude scaling transition for large earthquakes Measuringb= 15 for large earthquakes. 2012

Magnitude-frequency relation for small earthquakes; a clue to the origin of f sub maxu of large earthquakes. Journal of Geophysical Research, B, Solid Earth and Planets 92(2): 1349-1355, 1987

Magnitude-frequency relation for small earthquakes; a clue to the origin of f (sub maxú of large earthquakes. Eos, Transactions, American Geophysical Union: 4, Pages 1112. 1986., 1986

Reliability of determining the parameters of Gutenberg-Richter distribution for weak Earthquakes in Garm, Tajikistan. Izvestiya, Physics of the Solid Earth 48(9-10): 698-720, 2012

Is there a basis for preferring characteristic earthquakes over a Gutenberg-Richter distribution in probabilistic earthquake forecasting?. Bulletin of the Seismological Society of America 99.3, 2009

Decreases in the magnitude-frequency beta-value prior to large earthquakes in Kanto, central Japan. Pages 20 2001, 2001

Earthquakes; a media frenzy or a geologist's delight; an analysis of bibliographic citations of four major earthquakes over magnitude 6.0 on the Richter Scale. Abstracts with Programs - Geological Society of America 33(6): 61, 2001

The magnitude-frequency distribution on the southern San Andreas Fault follows the Gutenberg-Richter distribution. Eos, Transactions, American Geophysical Union 89.53, Suppl., 2008

Power-law and log-periodic changes in precursory phenomena prior to large earthquakes. Congres Geologique International, Resumes 33, 2008

Evidence for parabolic fractal behavior (Gutenberg-Richter law) in the magnitude-frequency distribution of a seismic sample. Comptes Rendus de l'Academie des Sciences, Serie II Sciences de la Terre et des Planetes, 1997

Magnitude of velocity anomalies prior to earthquakes. Journal of Geophysical Research: Solid Earth 101(B5): 11217-11223, 1996