THE 9/56 YEAR CYCLE: SEASONALITY & EARTHQUAKES

THE 9/56 YEAR CYCLE: SEASONALITY & EARTHQUAKES

David McMinn

Seasonality in the timing of major earthquakes can show up quite strongly in the 9/56 year seismic cycle. Earthquakes occurring in one sector of the 9/56 year grid will tend to occur around the same calendar months. This effect showed up strongly for the historical earthquakes in California, New Zealand, eastern Canada and Iceland, which has been discussed in the following text. This strong seasonality has not been fully appreciated within seismology.

NB: The dates of earthquakes are presented as YYYYMMDD in the tables.

California

The US Geological Survey (USGS) listed earthquakes occurring in California, Nevada and Baja California for the period 1769 to 2005. This included “known earthquakes with a magnitude of at least 6.0 and selected smaller events”. Of the 26 major quakes (mag => 7.0) in the 1800-2005 period, 7 major quakes in California – Nevada – Baja California happened in the 2.7 months to December 21 and in only three 56 year sequences (Sqs 43, 52 & 05).

The three 56 year sequences comprised 5% of the complete 9/56 grid and contained:
* 27% of all Californian earthquakes.
* 58% of October to December Californian earthquakes.

Amazingly, the three sequences experienced 7 major events in the 2.7 months to December 21.

Table 1 THE THREE KEY 56 YEAR SEQUENCES & MAJOR CALIFORNIAN EARTHQUAKES
Sq 43		Sq 52		Sq 05
1803	+ 9	1812 1208 1221	+ 9	1921
1859	+ 9	1868 1021	+ 9	1877
1915 1003 1121	+ 9	1924	+ 9	1933
1971	+ 9	1980 1108	+ 9	1989 1018
Years in bold contained big quakes (mag => 7.0) in the 2.6 months ending Dec 21.

In Sequences 52 and 95, two additional important quakes occurred on December 21, 1932 and January 26, 1700.

Sq 52		Sq 05
1700 Jan 26	+ 9	1709
1756	+ 9	1765
1812	+ 9	1821
1868	+ 9	1877
1924	+ 9	1933 19321221
1980	+ 9	1989

In Sequences 41 & 50, two major quakes happened in January, while in Sequences 12 and 21 they occurred in the month to June 15.

Sq 41		Sq 50
1857 0109	+ 9	1866
1913	+ 9	1922 0131
1969	+ 9	1978

Sq 12		Sq 21
1884	+ 9	1893
1940 0519	+ 9	1949
1996	+ 9	2005 0615

The April 18, 1906 San Francisco quake occurred in sequence 34, close to the May 18, 1980 Mt St Helens eruption in Sequence 52 in the 9/56 year grid.

Sq 34		Sq 43		Sq 52
1850	+ 9	1859	+ 9	1868
1906 0418	+ 9	1915	+ 9	1924
1962	+ 9	1971	+ 9	1980 0518

Three Californian earthquakes were timed between September 1 and November 26 in the following grid. This included two lesser events (mag < 7.0).
* November 23, 1873 mag 6.8. Owens Valley.
* November 26, 1976 mag 6.8.

Sq 48		Sq 01
		1761	+ 9	1770
1808	+ 9	1817	+ 9	1826
1864	+ 9	1873 1123	+ 9	1882
1920	+ 9	1929	+ 9	1938
1976 1126	+ 9	1985	+ 9	1994 0901

6 Californian earthquakes were timed in the 2.4 months to April 18 in the following 9/56 grid. This included two lesser events (mag < 7.0).
* April 11, 1872 mag 6.8. Owens Valley.
* February 9, 1890 mag 6.8 San Jacinto fault.

The major earthquake of August 17, 1991 happened in the same month as the 6.9 mag August 3, 2009 Baja California quake. Both occurred in close proximity in the 9/56 year grid.

Of the five major Californian earthquakes (mag > 7.0) recorded for February to April, four happened in this grid. Thus, 27 % of the 9/56 year cycle gave 80% of events in February to April.

									1805	1814	1823	1832	1841	1850
1780	1789	1798	1807	1816	1825	1834	1843	1852	1861	1870	1879	1888	1897	1906 0418
1836	1845	1854	1863	1872 0326 0411	1881	1890 0209	1899 0416	1908	1917	1926	1935	1944	1953	1962
1892 0224	1901	1910	1919	1928	1937	1946	1955	1964	1973	1982	1991 0817	2000	2009 0803
1948	1957	1966	1975	1984	1993	2002	2011
2004	2013

In the following five 56 year sequences, five Californian earthquakes (=> 6.8 mag) happened in April 21 – June 28, as well as November 04 – December 16.

1862	1871	1880	1889	1898
1918 0421	1927 1104	1936	1945	1954 1216
1974	1983	1992 0425 0628	2001	2010

Hawaiian Earthquakes

Hawaiian earthquakes also tended to occur within a similar section of the 9/56 year cycle, as recorded for California. The USGS listed 15 major quakes on the island of Hawaii (see Appendix 7). Of this figure, 8 took place in the 11 months ended August 22 of those years in Table 2, whereas 1.5 could be expected by chance.

Seasonality also showed up in Hawaiian earthquakes. Two events occurred around June 26 in the following 9/56 year grid.

Sq 34	Sq 43	Sq 52	Sq 05
		1868	1877
1906	1915	1924	1933
1962 Jun 27	1971	1980	1989 Jun 25
2018

Three additional events happened in the month to April 22.

Sq 52	Sq 05	Sq 14	Sq 23
1868 Mar 28 Apr 02	1877	1886	1895
1924	1933	1942	1951 Apr 22
1980	1989	1998	2007

Two quakes happened in the month to October 15.

Sq 13	Sq 22
1886	1895
1942 Sep 25, 1941	1951
1998	2007 Oct 15, 2006

Iceland

The Icelandic Meteorological Office published a listing of major Icelandic earthquakes between 1706 and 2000. There were 25 events with a magnitude =>6.0, NONE of which occurred in the four months to January 10.

Of the total figure, 19 fell in the 8 months beginning January 15 of those years in the 9/56 year grid shown in Table B, Appendix 17, a finding that was extremely significant (p < 10^-6).

Additionally, 11 major Icelandic quakes were recorded in 6 56 year sequences in an 9/56 year pattern. These all happened in the 5.6 months between March 28 and September 10, with 8 taking place in the month to September 6 (of which 5 occurred in an 1896 earthquake storm)..

			Sq 06		Sq 24
			1710	1719	1728
1739	1748	1757	1766 0405 0809	1775	1784 0814 0816
1795	1804	1813	1822	1831	1840
1851	1860	1869	1878	1887	1896 0826 0827 0905 0905 0906
1907	1916	1925	1934 0602	1943	1952
1963 0328	1972	1981	1990	1999	2008
Each 56 year sequence is separated by an interval of 9 years. Years in bold experienced a major earthquake (mag =>6.0) in the 5.75 months commencing February 28.

In the following 12 56 year sequences, 7 earthquakes happened in the 3.5 months commencing January 25, with the one on August 9, 1724.

					1706 0420	1715	1724 0809	1733	1742	1751	1760
1717	1726	1735	1744	1753	1762	1771	1780	1789	1798	1807	1816
1773	1782	1791	1800	1809	1818	1827	1836	1845	1854	1863	1872 0418 0418
1829 0202	1838	1847	1856	1865	1874	1883	1892	1901	1910 0222	1919	1928
1885 0125	1894	1903	1912 0506	1921	1930	1939	1948	1957	1966	1975	1984
1941	1950	1959	1968	1977	1986	1995	2004
1997	2006
Each 56 year sequence is separated by an interval of 9 years. Years in bold experienced a major earthquake (mag =>6.0) in the 3.5 months commencing January 25 and May 6. Only one quake on August 9, 1724, did not conform to this finding. Source of Raw Data: Icelandic Meteorological Office.

This may be better presented as an 18/56 year cycle, in which the quakes happened in the 2.5 months to May 6.

		1706 0420	+ 18	1724	+ 18	1742	+ 18	1760
1744	+ 18	1762	+ 18	1780	+ 18	1798	+ 18	1816
1800	+ 18	1818	+ 18	1836	+ 18	1854	+ 18	1872 0418 0418
1856	+ 18	1874	+ 18	1892	+ 18	1910 0222	+ 18	1928
1912 0506	+ 18	1930	+ 18	1948	+ 18	1966	+ 18	1984
1968	+ 18	1986	+ 18	2004

Each 56 year sequence is separated by an interval of 9 years. Years in bold experienced a major earthquake (mag =>6.0) in the 3.5 months commencing January 25 and May 6. Only one quake on August 9, 1724, did not conform to this finding.. Source of Raw Data: Icelandic Meteorological Office.

New Zealand

The Institute of Geological & Nuclear Sciences presented a map of New Zealand major quakes from 1848 to 2007 epoch (see Table A, Appendix 7 of major quakes => 6.9 mg), which were 'notable shallow earthquakes' (generally less than 30 kms depth). Of the 17 given, 11 showed up in the 11 months beginning January 20 of those years in the combined 36 ysc Series 1 & 2 (see Table B, Appendix 7). In contrast, the expected frequency was only 3.4.

In the following 18/56 grid, five New Zealand quakes happened in the 1.5 months commencing January 23.

Sq 03		Sq 21				Sq 01
1819	+ 18	1837	+ 18	1855 0123	+ 18	1873
1875	+ 18	1893 0212	+18	1911	+ 18	1929 0309
1931 0202 0213	+ 18	1949	+ 18	1967	+ 18	1985
1987	+18	2005

In the following 18/56 grid, four New Zealand quakes happened in the four months ending October 10.

Sq 52				Sq 32
1812	+ 18	1830	+ 18	1848 1016
1868 1019	+ 18	1886	+ 18	1904
1924	+ 18	1942 0624 0802	+ 18	1960
1980	+ 18	1998

Eastern Canada

Eastern Canada has recorded events from the mid 17th century (Geological Survey of Canada). Strangely, all 9 major eastern quakes (mag => 6.0) occurred in the 4.5 months October 15 to February 28. Six of these quakes happened within the 9/56 year pattern presented subsequently, a figure that compared with an expected frequency of 1.5.

EARTHQUAKES IN EASTERN CANADA (mag => 6.0)
7.0	February 5, 1663	Charlevoix – Kamouraska region
6.0	December 6, 1791	Charlevoix – Kamouraska region
6.0	October 17, 1860	Charlevoix – Kamouraska region
6.0	October 20, 1870	Charlevoix – Kamouraska region
6.2	February 28, 1925	Charlevoix – Kamouraska region
7.2	November 18, 1929	Offshore New foundland
7.3	November 20, 1933	Baffin Bay, NWT
6.2	November 1, 1935	Temiscamingue, Quebec
6.3	December 25, 1989	Ungava, Quebec
Quakes in bold occurred in the 4.5 months commencing October 15 of those years in the 9/56 year patterns presented subsequently. Source: Geological Survey of Canada

						Sq 52	Sq 05
		1664	1673	1682	1691	1700	1709	1662 16630205
1702	1711	1720	1729	1738	1747	1756	1765	1774
1758	1767	1776	1785	1794	1803	1812	1821	1830
1814	1823	1832	1841	1850	1859	1868	1877	1886
1870 1020	1879	1888	1897	1906	1915	1924 19250228	1933 1120	1942
1926	1935 1101	1944	1953	1962	1971	1980	1989 1225	1998
1982	1991	2000	2009
Years in bold contain eastern Canadian major earthquakes in the 4.5 months commencing October 15 of those years in the table.

Sun - North Node Angles

The lunar nodes are imaginary points in the heavens where the plane of the Earth’s orbit around the Sun (the ecliptic) is cut the plane of the Moon’s orbit around the Earth. The north (ascending) node occurs where the Moon crosses the ecliptic from south to north.

The Moon, Sun and the lunar north node repeat 0 and 180 angles to within one degree every 9.0 and 56.0 solar years (David McMinn). These very close alignments are the key to understanding the Moon Sun basis of the 9/56 year cycle.

Any event falling preferentially in 9/56 year cycle will always have the lunar north node located in two segments approximately diagonally opposite on the ecliptical circle. Thus the Sun will form angles to the north node approximating to the formula X + Y = 180^o.

When earthquakes happen in an 18/56 year cycle, the lunar north node will always be located in one segment on the ecliptical circle. Thus, the Sun will form similar angles to the north node, when events occur around the same month.

The emphasis on the 0 and 180 angles between the Sun and the north node, implies that the 1st and 2nd harmonics may be important factors determining the observed seasonality of earthquake cycles.

Apogee

Apogee is the point (given in ecliptical degrees) in the lunar orbit, where the Moon is the greatest distance from Earth, while perigee is the least distance. In the lunar apse cycle, the apogee – perigee axis (apsides) rotates counter clockwise around the ecliptical circle from spring equinox to spring equinox every 8.8474 tropical years. The apsides axis is very important in oceanic tides on Earth. When the full/new Moon is at apogee, the amplitude of tides in New York Harbor is 50% lower than when the full/new Moon is at perigee. Apogee could be expected to play a key role in any Moon Sun seismic effect.

Apogee takes 5.995 tropical years to complete one cycle north node to north node. The 3^rd harmonic is crucial as the 6.0 year NN - apogee cycle is one third of an 18.030 year Saros eclipse cycle and the 56 year cycle divided by 6 gives 9.3333 tropical years (9 plus one third).

9.0 divided by 8.8474 years of the apse cycle gives 1.02 and dividing 56.0 by the same value gives 6.33 (6 and one third). Again the emphasis is on the 1st and 3rd harmonics in the 9/56 year grid. Any events that fall with statistical significance in 9/56 year grid and around the same month will have apogee approximately 120^o on the ecliptical circle.

From the Californian October to December events in Table 1, Apogee is sited about 120^o apart around the ecliptical circle at 075 - 085 E^o, 200 - 215 E^o and 325 E^o. This was to be expected.

The 3rd harmonic in relation to Apogee and the 9/56 year cycle is either an cyclic artifact or very important in understanding how the 9/56 year cycle actually functions.

Year	Mth	Day	GMT	Mag	Sun E^o	Moon E^o	Phase A^o	NN E^o	Apo E^o	NN- Sun Angle A^o
Apogee btn 200 & 215 E^o
1812	12	08	na	7.0	257	311	054	143	212	114
1812	12	21	19.00	7.0	270	135	225	142	213	128
1980	11	08	10.27	7.2	226	232	006	135	204	091
1989	10	18	00.04	7.1	205	069	224	322	208	243
Apogee at 325 E^o
1868	10	21	15.53	7.0	209	279	070	142	325	067
Apogee btn 075 and 085 E^o
1915	10	03	06.52	7.3	189	120	291	315	075	234
1915	11	21	00.13	7.1	238	053	175	312	081	286

In Summary

These findings on earthquakes, seasonality and the 9/56 year cycle appear promising, but the ultimate conclusions will have to wait further more detail assessments. Hopefully future research will be able to determine the windows when maximum Moon Sun tidal effects can trigger major earthquakes. Determining such windows could save thousands of lives and prevent much property damage. Unfortunately, the Moon Sun mathematics are well beyond the capabilities of the author - a PhD in tidal harmonics would be a great asset in any such research.