WEATHER PHENOMENA

 

 

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:

 

TROPICAL DEPRESSION 21W   

 

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TD    21W      2019-10-17  00:00 UT  18.7N  129.5E   40 kts  northeast of Philippines           

 

 

Tropical Depression 21W  formed east of the central Philippines with winds up to 40 kts. This system is moving to the west and may have helped promote the M 6.4 in Mindanao, Philippines today. Further seismic enhancement with this storm is likely as it moves through the region.

 

TIDAL EFFECTS ON SEISMICITY

 

The full moon arrived on October 13 at 21:08 UT. Longitudes which were sub-solar at this time area near 45 East and 135 West longitude. These include areas of Turkey and Iran in the east and the northwestern edge of the North American Plate in the west. These are most likely to see tidal triggering at this time but tidal triggering can occur in a number of tectonic settings. Seismic enhancement is most likely a promoter of seismicity near local solar noon and local solar midnight.

 

 

October 17, 2019 is the seventeenth 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 13 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

 

Arctic MB>=4.0 -30 -1.9 0.05

Greece MB>=4.0 -9 -2.3 0.05

N Indonesia MB>=4.0 -35 -1.9 0.05

Utah MB>=0.0 -10 -2.0 0.05

Caribbean MB>=4.0 -22 -2.5 0.04