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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STYPH CHANTHU  2021-09-17  00:00 UT  33.4N  129.2E   50 kts  Honshu, Japan


Typhoon Chanthu (TD 19W) continued today over Honshu, Japan with winds up to 50 kts. It is expected to track to the east and north over the next week and possibly to impact regional seismicity in Honshu, Japan around September 15-18. A moderate to large earthquake near Honshu is possible in the next several days with this storm.




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TS    NICHOLAS 2021-09-17  00:00 UT  31.1N   93.1W   15 kts  Southern Louisiana


TS Nicholas continued today in the area of Southern Louisiana with winds up to 15 kts. It is expected to track to the northeast over the next two days passing along the east coast of Texas and into Louisiana. Rainfall is expected to be extreme. Some seismicity in Texas and Tennessee is expected to be enhanced as this storm is in the area.






September 17, 2021 is the tenth 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


Alaska MB>=3.0 6 2.0 0.05

Greece MB>=4.0 8 2.0 0.05

Hawaii MB>=2.0 19 2.7 0.02

Kuriles MB>=4.0 22 1.9 0.05

Mammoth Lakes MB>=3.0 19 2.2 0.05

East Pacific Rise MB>=4.0 38 2.3 0.05

Hindu Kush MB>=4.0 20 2.9 0.01


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


No Regions