Ring of Fire is rampant with activity ... except for North American West Coast.
[
link to earthquake.usgs.gov]
Has got to be a lot of stress in California.
I'm sure this has been discussed before, but I'm up early, so...
Consider from 1857 to 1923 there were five large California quakes, with approximately 15 year cycle between them.
These 15 year spreads presented quakes of 7.2 to 7.9.
The cycle ramped up and back down like a 15 year amplitude sine wave ~
From 1923 to 1992 the cycle continued on a shorter time frame of approximately 6 years (not exactly 6 but close enough for me this early) between large quakes, an additional seven quakes.
This shorter time between quakes presented smaller magnitude large quakes from 6.6 to 7.5
Keeping with the cycle starting in 1992 the interim between large quakes starts at approximately 2.5 years, but we have not had a large quake since a 7.1 in 1999.
Just my call, but ... this puts the cycle approximately 12 to 15 years.
Coming up on 2014 we are at 15 years from the last large quake.
Considering the 15 year cycle of the 1857 to 1923 7.8 and 7.9 quakes, the longer we wait the bigger IT gets.
Just thinking ...
Mag Year Interim
7.9 1857 0
7.8 1872 15
7.9 1906 34
7.3 1922 16
7.2 1923 1
7.3 1927 4
7.1 1940 13
7.5 1952 12
6.6 1971 19
7.2 1980 9
6.9 1989 9
7.2 1992 3
7.3 1992 0
6.7 1994 2
7.1 1999 5
N/A 2009 9
??? 2014 13 15 Years without 6.6+
??? 2018 17
7.9 Jan. 9, 1857 Fort Tejon
7.8 March 26, 1872 Owens Valley
7.9 April 18, 1906 San Francisco
7.3 Jan. 31, 1922 West of Eureka
7.2 Jan. 22, 1923 Mendocino
7.3 Nov. 4, 1927 SW of Lompoc
7.1 May 18, 1940 El Centro
7.5 July 21, 1952 Kern County
6.6 Feb. 9, 1971 San Fernando
7.2 Nov. 8, 1980 West of Eureka
6.9 Oct. 17, 1989 Loma Prieta
7.2 April 25, 1992 Cape Mendocino
7.3 June 28, 1992 Landers
6.7 Jan. 17, 1994 Northridge
7.1 Oct. 16, 1999 Ludlow
Last Edited by FletcherColins on 11/03/2013 09:40 AM