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:


No tropical cyclones are currently active.







The full moon will arrive on February 27, 2021 at 08:17 UT. Longitudes which are at local solar midnight are near 123 West while those at local solar noon are near 67 East at this hour. These include the western U.S. and Canada and the California coastline in the west and Central Asia, Pakistan, India, Iran in the east. These are the areas most likely to see tidal forcing of seismicity with this full moon. A moderate to strong earthquake is possible with this tidal event. These are most likely near solar noon and midnight but may occur in other localities and times as well. Probability for a large tidally induced event in the next week is considered low to moderate.


February 23, 2021 is the twelfth 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


Australia MB>=4.0 38 3.0 0.01

So Indonesia MB>=4.0 49 3.7 0.01

Global MB>=5.0 5 1.9 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


Tonga MB>=4.0 -28 -2.0 0.05

Turkey MB>=4.0 -10 -2.0 0.05