Posted by Lowell on April 28, 2002 at 00:18:55:
Moving onto other matters. The long dry spell in southern California is continuing as I write this. But I thought it would be interesting to see how unusual this period without a Ml>=3 in southern California really is. I did a search of all the various catalogs containing earthquakes in the southern California region and found the times between consequetive event of Ml>=3. When the catalog contains the region of southern California excluding the Calexico region (36N-32.5N, 125W - 114W), the longest interevent times (in days) - last day is identified by Month, day, year are: Days M D YR 37.976250 2 21 1958 31.510162 6 24 1960 30.191979 10 5 1960 29.399317 12 20 1966 29.046458 8 13 1979 27.585949 4 11 1965 26.994120 5 15 1966 24.868923 10 1 1958 24.245220 5 11 1980 23.947245 1 15 1962 23.375544 10 9 1990 22.522014 4 2 1970 22.037407 12 10 1949 21.976481 7 19 1989 20.738090 7 15 1964 20.625290 6 11 1977 20.416262 12 21 1967 20.337500 1 29 1959 20.261111 7 14 1936 20.253449 12 11 1998 20.252234 12 2 1989 20.090486 6 18 1932 20.007280 11 7 1956 The longest time between earthquakes of Ml>=3 in the region in the past 20 Years was the 23.37 day drought which ended on October 9, 1990 followed by A 21.97 day period between Ml>=3 earthquakes ending on July 19, 1989 and A 20.25 period ending on Dec 11, 1998 and on Dec 2, 1989. The longest dry spell for the area INCLUDING the Calexico region (32 - 36N 125W-114W) was 19.34 days ending on Oct 5, 1990 followed by a 17.99 day spell ending on Jan 8, 1991 and 17.17 days ending on Dec 5, 1983. Earthquakes which ended these droughts were: Oct 9, 1990 - South of Simi Valley Ml 3.2 July 19, 1989 - Joshua Tree Ml 3.0 Dec 2, 1989 - Anza area Ml 4.1 Dec 11, 1998 - Lake Isabella Ml 3.6 And Off coast of So. California Ml 3.6 And Oct 5, 1990 - Calexico region Ml 3.1 Jan 8, 1991 - Anza area Ml 3.4 Dec 5, 1983 - Calexico region Ml 3.8 And Lake Isabella Ml 3.1 The current drought (not including Calexico) started on April 5, 2002 At 08:02 UT. This spell without a Ml>=3 has now lasted about 23 days Making it the second longest drought in the past 20 years. Another Quarter of a day (if we don't have an event my morning) it will be the Longest in the past 20 years.
Including Calexico, the period without a Ml>=3 has now continued since April 11 at 13:43 UT, a period of 16.5 days. The 7th longest on record. But another day or two and we will be seeing record-breaking dry spell For this area as well. It would appear that the region is overdue for that Ml>=3 earthquake, If past history is any guide, it should happen any hour now.
Follow Ups:
● Re: The Southern California earthquake record-breaking drought - chris in suburbia 09:28:00 - 4/28/2002 (15296) (1)
● Re: The Southern California earthquake record-breaking drought - Lowell 10:31:19 - 4/28/2002 (15297) (1)
● Re: The Southern California earthquake record-breaking drought - Canie 12:30:11 - 4/28/2002 (15301) (0)
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