Some seismicity may be affected by weather due to wind, tidal surge and air pressure systems effects of  the continental mass compared with adjoining plate masses. During the tropical storm season in the Northern Hemisphere we keep an eye on tropical storms which may affect seismicity according to our models.  Currently the following tropical storms appear to have potential to affect seismicity in the coming week:





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TC    FREDDY   2023-02-07  00:00 UT  14.4S  117.0E   90 kts  South of Sumbawa      


TC Freddy (11S) continued today in the area south of Sumbawa, Indonesia with winds up to 90 kts.  This epicenter is at the fourth node (90 degrees) from the M 7.8 in Turkey today and may have contributed to the occurrence of that event. This storm is expected to track to the southwest reaching winds up to 125 around February 8, 2023. It could enhance regional seismicity in Central Indonesia while in the area. The antipode is at 15N 63W in the area of Guadeloupe where some enhanced seismicity may occur from focused energy from TC Freddy.


A tropical cyclone may be forming northeast of Australia. This system is currently located at 13S 154E and moving to the SW with winds up to 33 kts. Promoted seismicity with this system is unlikely at this time.





The full moon arrived at 18:29 UT on February 5, 2023. Longitudes which are at local solar noon are near 100 West while those at local solar midnight are near 80 East. In the west these include areas of the central U.S. including Texas and Oklahoma/Kansas and Canada and western Mexico and part of the East Pacific Rise while in the east the areas of Afghanistan, Hindu Kush, Pakistan, China, central Asia and areas of the Indian Ridge system are included. These are the most likely regions to be subject to tidal triggering from February 2-8. While a major earthquake is unlikely at this time, regions of western Mexico and/or Central Asia could see a strong quake with this full moon. A moderately strong earthquake is considered likely in the period within three days of this full moon.



February 7, 2023 is the sixteenth day after the beginning of the new lunar month.  Regions most likely to experience tidal triggering on this day (With associated magnitude ranges; the percent change in seismicity rate over background seismicity rate on this day of the lunar month; statistical z-value and significance level) are:


Region Magnitude range %change z-value Significance level


Kermadec MB>=4.0 14 2.0 0.05

Nevada MB>=2.0 22 3.3 0.01

Spain MB>=4.0 35 2.5 0.03

Puerto Rico MB>=4.0 18 2.0 0.05



Regions expected to experience reverse triggering (i.e. they are unlikely to experience a significant event at this period of the lunar cycle) are:



Region Magnitude range %change z-value Significance level


So.California MB>=0.0 -8 -2.1 0.05