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)


Qinghai China to West Chile Rise, 

Kermadec Islands to Algeria, northwest Africa, Southern Spain, 

North Island, New Zealand to Algeria, North Atlantic,

Honshu Japan to

West Chile Rise to Central China, Nepal, Tajikistan, 


Outer shadow zone edge (141-148 degrees)


Qinghai China to

Kermadec Islands to Congo, Iraq, Ascension Is, Reykjanes Ridge, Iceland, 

North Island, New Zealand to

Honshu Japan to Southern Peru, West Chile Rise, Northern Chile,


Node 3 (120 degrees)


Qinghai China to Jalisco, Mexico, 

Kermadec Islands to  La Soufriere, Barbados, Tajikistan, Baffin Bay, Quebec,  Hindu Kush,  

North Island, New Zealand to  La Soufriere, Namibia, Barbados, Xinjiang, China, Tajikistan,  Puerto Rico,

Honshu Japan to Guadeloupe, Panama,


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


Qinghai China to  Mammoth Lakes, California, South Island, New Zealand, Kermadec Islands, Southern California, Northern Mid-Atlantic

Kermadec Islands to Texas, Wyoming, Caribbean Sea, Kansas,  Northern India, Louisiana, Indian Ridge, Beaufort Sea, Mongolia, Carlsberg Ridge, Siberia, Kansas, Oklahoma, Northern Alaska,  Myanmar,

North Island, New Zealand to Texas, Wyoming, Southern India, Central Alaska, Southeast Alaska, Mongolia, West Texas, Carlsberg Ridge, South Indian Ocean, Myanmar,  Southern Alaska, El Salvador, Costa Rica, Idaho, Oklahoma, Utah, Washington State, Carlsberg Ridge, 

Honshu Japan to Crozet Islands, North East Pacific Rise, Mayotte, Congo, Guerrero, Mexico, North Atlantic, Lake Victoria, Tanzania, Northern Chile, Azores, Oaxaca, Guerrero,  Mexico,  


Node 4 (90 degrees)


Qinghai China to

Kermadec Islands to Alaska, Oaxaca, Guerrero Mexico, Utah, Washington, Chile,

North Island, New Zealand to Kuril Islands,  Carlsberg Ridge,

Honshu Japan to Indian Ocean, Illinois, Quebec,  South Island, New Zealand, 


Node 5 (72 degrees)


Qinghai China to Congo, 

Kermadec Islands to West Chile Rise,

North Island, New Zealand to Aisen, Chile, West Chile Rise,

Honshu Japan to Tonga, San Francisco, northern California, Iran, Idaho, Norfolk Island, Fiji, Armenia, 


Node 6 (60 degrees)


Qinghai China to Andreanof Islands,

Kermadec Islands to Ceram, Indonesia, Mariana Islands, 

North Island, New Zealand to Ceram, Indonesia, Hawaii, 

Honshu Japan to NE Australia, Greenland Sea, 


Node 7 (52 degrees)


Qinghai China to

Kermadec Islands to New Guinea, South of New Guinea,  Hawaii

North Island, New Zealand to  South of New Guinea,

Honshu Japan to Solomon Islands, Beaufort Sea, Andaman Is, Tajikistan,  Timor, Lombok, Sumbawa, Indonesia,