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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TYPH  LAN      2017-10-18  00:00 UT  12.9N  132.3E   80 kts  East of Central Philippines


Typhoon Lan continued today east of the Central Philippines today with winds up to 80 kts. It is expected to track to the north and not to encounter land in the next several days. It may reach Honshu, Japan as a major typhoon and could trigger a strong earthquake in that region after passing through.



The new moon will arrive at 19:12 UT on October 19. Maximum tidal stresses should occur near longitudes 108W and 72E including much of western U.S. and

Mexico in the west and in the east in central Asia, including Pakistan and  Afghanistan and in the South Indian Ocean. Moderate to strong earthquakes  in the region could be triggered by strong tidal stresses. This is most like around October 19-21, 2017 when combined with promotion from geomagnetic effects.



October 18, 2017 is the twenty-eighth day after the beginning of the 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>=4.0 6 2.0 0.05

Aleutians MB>=4.0 40 3.1 0.01

New Britain MB>=4.0 25 2.6 0.03

So. California MB>=3.0 67 2.3 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


Central So America MB>=4.0 -20 -2.0 0.05