Statistical evidence indicates that some triggering or promotion forward in time can occur in regions which are under high stress due to additional stress events of  small size. Among these are surface and body waves passing through a region. Triggering may be dynamic with the promoted earthquake occurring at the same time as the stress event or delayed with an earthquake occurring later in time but still related to the stress event through water lubrication or other various geophysical effects on the faults. We have argued in this report for the past 35 years that this effect is most observable where the seismic waves are largest. In general this occurs at distances from the rupture ends of  the earthquake producing those waves (mainshock) which we have termed nodal distances. These are defined by the formula D=360*m/n where D is the distance in degrees and m<=m where n an m are small integers. These are also the locations of  the maximum corrections to magnitude in the standard Jeffreys-Bullen tables. In addition there is focusing of  seismic energy from reflections and refractions of f the core-mantle and the inner-outer core boundary of  the earth. This focuses energy at the surface in the distance between 101 and 108 degrees (core-mantle) and 141-148 degrees (inner-outer core boundary). In this report we monitor seismicity at these distances following major earthquakes as experience has shown that strong and/or unusual earthquake are much more likely to occur at these distance from the mainshock.


Antipodal (~180 degrees)


Peru to

Ecuador to Sumatra, Indonesia, 

Mindanao, Philippines to

Loyalty Islands to

Minahasa to


Outer shadow zone edge (141-148 degrees)


Peru to Papua New Guinea, Honshu, Japan, Pakistan,  

Ecuador to Mid-Indian Ridge, Kyushu, Japan, Gujarat, India, Ryukyu Islands, New Guinea,  Western Australia,

Loyalty Islands to South Atlantic, Crete,

Minahasa to Buenos Aires, Argentina, Baja California, Central Chile, Oaxaca, Mexico, 


Node 3 (120 degrees)


Peru to Near Islands,

Ecuador to Reykjanes Ridge, 

Mindanao, Philippines to Oklahoma, South Sandwich Islands.  

Loyalty Islands to South Carolina, Venezuela, Zimbabwe, Ontario, Arctic Ocean, 

Minahasa to Tristan de Cunha, Utah, Baja California, South Sandwich Is, 


P- and S- shadow zone edge and node 7 (101-110 degrees)


Peru to Turkey, Unimak, Alaska, Fiji, Northern Alaska, Fiji, Aegean Sea, Hungary, 

Ecuador to  South Africa, Turkey, Crete, Kermadec Islands, Rat Islands, Near Islands, Aegean Sea, Fiji,  South Africa, Ionian Sea, Macquarie Islands, Fiji, New Zealand, Crete, 

Mindanao, Philippines to Iceland, Montana, Jan Mayen, Southern, central, Northern California, Utah,

Loyalty Islands to Chiapas, Mexico, Bouvet Island, Pakistan, Peru, Oaxaca, Mexico, Mississippi, Central Chile, Nebraska, Central Colorado, Missouri, Tajikistan, Chiapas, Oaxaca, Mexico,  

Minahasa to Antarctic-Pacific Ridge, British Colombia, Ionian Sea, Sicily, Coast of Oregon, Vancouver,


Node 4 (90 degrees)


Peru to Southe Africa, 

Ecuador to Beaufort Sea, Northern Alaska, 

Mindanao, Philippines to

Loyalty Islands to SE Alaska, Rivello Gigedo Is, Southern Alaska, northern Baja California, Southern California,

Minahasa to southern Alaska, Romania, Greece, northern Alaska


Node 5 (72 degrees)


Peru to Idaho, Northern Mid-Atlantic, Northern, Central California, 

Ecuador to Reykjanes Ridge, 

Mindanao, Philippines to

Loyalty Islands to

Minahasa to South Indian Ocean, Iran, Ural Mts, 


Node 6 (60 degrees)


Peru to

Ecuador to Northern California, Azores, 

Loyalty Islands to

Southern Alaska to Oaxaca, Mexico, Central Peru, Fiji, Banda Sea,  


Node 7 (52 degrees)


Peru to

Ecuador to Utah, Wyoming, Southern California, 

Komandorsky Islands to Central Luzon, Philippines, Yellowstone,

Loyalty Islands to Australia, Mindanao,