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Some Earthquakes of Interest to This Astrologer

Updated on October 9, 2013
retrojoe profile image

Has studied astrology/historical seismology since the late '70s in San Francisco. Published in the ISAR International Astrologer in 2012.

Map showing Shaangxi province in china and the provinces affected by the 1556 Shaanxi earthquake.
Map showing Shaangxi province in china and the provinces affected by the 1556 Shaanxi earthquake. | Source

This hub plans to explore some of the more interesting facts about significant earthquakes, beginning with the deadliest quake ever. Not only did the great Shaanxi, China earthquake occur in the middle of winter, but at approximately 5am in the morning (per "Earthshock" by B. Booth and F. Fitch, 1979). Almost everyone was caught sleeping and the cave homes that many were dwellers in at the time collapsed, killing the vast majority of people within. The estimate of the total number of dead came to 830,000; some estimates give that it was more like one million. The year was 1556.

The dates often given for this catastrophe are either in January on the 23rd or the 24th, or in February on the 2nd or the 3rd. Of these, January 23rd comes up the most. The January dates are given in the old style Julian calendar which was used within most of the civilized world at the time and the February dates were displayed using the new Gregorian style calendar (which wasn't implemented for the first time till about 27 years after this earthquake). I believe, although the 2nd or later dates within each group of dates is given less often, that those are the more accurate dates. The primary reason for the earlier dates are, in my opinion, due to conversion from a lunar calendar month where the first day of each month began with the day of the New Moon. However, as I understand it, back in the mid 16th century, the Chinese counted the start of each month with the date where the crescent moon was first observed following the new moon which would usually be the day after the not yet visible new moon.

As I said earlier, the January dates were based on the Julian calendar. The Chinese didn't adopt the Gregorian calendar until the year 1912 (the Christian world converted from the Julian to the Gregorian calendar back on October 5th, 1582). The difference between the two calendars was 10 days in the 16th century and thus converting their lunar calendar to Julian yielded January 24 and, adding 10 days, resulted in the Gregorian calendar date of February 3. If you want to calculate the astronomical or astrological planetary positions as they were on that terrible day, one must use the Gregorian date or how the date would have looked if we used the same calendar that we use today.

One interesting fact about many significant earthquakes in history is that many more occur on either February 3 or 4 than one would expect from chance. The most noteworthy are given below, all occurring on (or likely on) either of these two dates. All landed inside astrologically defined window areas. Earthquakes were almost five (4.85) times more likely to fall on either of these two dates (in the Gregorian calendar) than on an average date (they were extracted from a database of 371 significant earthquakes that fall within astrologically defined windows). What makes this fact even more striking is that this spike in noteworthy quakes occurs in a month that as a whole is below average. Actually lower than any month from a study I once did of 7.75 magnitude or greater earthquakes (

A list of significant earthquakes occurring on February 3rd or 4th (see notes for February 2nd and 1783 earthquakes).
A list of significant earthquakes occurring on February 3rd or 4th (see notes for February 2nd and 1783 earthquakes).

In an even more recent hub I looked at years that had much more than the average number of 8.0 magnitude earthquakes. Two years mentioned were 1946 which had 3 such quakes and 2007 which had 4. That data was extracted from a list at the USGS' web site. However, utilizing other sources with more up-to-date calculations of moment magnitude, especially for some of the older earthquakes, I discovered that 1906 also had 4 such earthquakes. Not only that, but if we look at the 15 month period from July 1905 through September 1906, we get 6 such quakes or one every 2.5 months! Two of these earthquakes actually happened just under half of an hour from each other and thousands of miles apart (which seismologists almost routinely state was just an unlikely coincidence). Both of these quakes are given below (for the 8/17/1906 date) in the list of the six quakes mentioned above. One exceptionally destructive earthquake that is missing from this list is that of the San Francisco earthquake of April 18, 1906. It was once thought to have been of 8.3 magnitude but now is considered to have been a 7.7 magnitude event.

8.0 magnitude or greater earthquakes occurring from July 1905 through September 1906.
8.0 magnitude or greater earthquakes occurring from July 1905 through September 1906.

Another year for the record books was 1960. It had the largest recorded earthquake ever of 9.5 magnitude (Mw) in Chile on May 22nd, but a deadlier earthquake was the Agadir, Morocco temblor of February 29, now estimated to have been of 5.84 magnitude (Mw; +-0.56), with over 13,000 casualties. This was perhaps the least powerful quake known to have been responsible for so many deaths.

The year 1976 was also a record year for the number of significant earthquakes that caused many deaths. In this same year, based on an unofficial estimate of over 655,000 deaths, the second most deadly earthquake known to humankind occurred in Tangshan, China during the early morning hours of July 28th. Although the magnitude is now estimated to be 7.57 (Mw; +-0.1), it occurred directly under the city, which was almost totally leveled. Other deadly earthquakes in that year included one in Guatemala (22,870 deaths on February 4th), Italy (965 victims on May 6th), Irian Jaya area of Papua New Guinea in Indoneisa (6,000 casualties on June 25th), the Philippines (8,000 perishing on August 16) and in Turkey (3,900 deaths on November 24th).

List of record deadly earthquakes that occurred in 1976.
List of record deadly earthquakes that occurred in 1976.

One huge earthquake that was never recorded (being inferred from historical records), but was probably at least one of 8.7 magnitude, is estimated to have occurred at about 9pm local time on January 26, 1700 (using the Gregorian calendar). This was the Great Cascadia earthquake which did much damage to the now Oregon and Washington coastlines and then, ten hours later, its resulting tsunami, caused damage across the Pacific Ocean in Japan. This last country was then subjected to great destruction from two earthquakes on December 31, 1703 and October 28, 1707 (both dates perhaps Julian), the first one causing a very destructive and deadly tsunami which is said to have taken as much as 100,000 lives alone. The second earthquake, causing from 5,000 to 10,000 deaths, was thought for many decades to have been the largest experienced in Japan until the huge March 11, 2011 earthquake and tsunami.

Although I have only circumstantial evidence that points to these last two quakes being recorded as Julian (and assumed in the present day to be in the Gregorian format) I have more likely proof that a Chinese earthquake that is reported from all sources that I can locate of occurring on September 2, 1679 in the Gregorian calendar was actually the result of being converted twice from the Julian format (by two different sources). The actual Gregorian date was August 23, 1679 and the Julian date 10 days earlier on the 13th per Robert Hooke (1635-1703), known as the "first British geologist", in his "Lectures & Discourses of Earthquakes & Subterraneus Eruptions" (reprint from the posthumous works of Robert Hooke, London, 1705). The reason that this is important to me of course is because if the event occurred on August 23, 1679, then it would have been inside an astrologically defined window and such would not be the case if it occurred on September 2, 1679. Ironically, I discovered proof that the Port Royal earthquake of 1692, rather than occurring on June 7th in the Gregorian calendar, actually happened 10 days later on June 17th ( This is ironic because if the correct Gregorian date is June 17th then the event was moved from being inside an astrologically defined window to outside of it. However, there was a hurricane in the Port Royal area on the same date, which I find intriguing, not only because it occurred simultaneously, but because it is the only case on record of a June hurricane in Jamaica (see page 267 of the Encyclopedia of Hurricanes, Typhoons, and Cyclones by David Longshore at Google Books).

I leave you with a list of a few historical earthquakes with hard to come by data and thus valuable to any astrologer who might want to create a chart for each event.

Obscure and corrected earthquakes of great interest to me from my database.
Obscure and corrected earthquakes of great interest to me from my database.

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