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)


Mindanao, Philipines to

Mongolia to

Los Lagos Chile to Qinghai, China, 

Dodecanese Islands to

Atacama  Chile to

Alaska Peninsula to South of Africa, 

Oaxaca Mexico to


Outer shadow zone edge (141-148 degrees)


Mindanao, Philipines to Puerto Rico, Dominican Republic, 

Mongolia to Central Peru, 

Los Lagos Chile to Philippines, Iran, India, Kurils, Sumatra, 

Dodecanese Islands to New Zealand, Southeast Pacific Rise, Loyalty Is, Vanuatu, Easter Island, Macquarie Islands, 

Atacama  Chile to Mariana Is, Sakhalin, Java, Sumbawa,  northern Honshu, Japan, Hokkaido, Tajikistan, Mariana Islands, Sumbawa,  

Alaska Peninsula to South Shetland Islands, South Georgia Islands, Mozambique, South Africa, 

Oaxaca Mexico to South Indian Ridge, Sumba, Flores Sea, Indonesia, Myanmar, Carlsberg Ridge, 


Node 3 (120 degrees)


Mindanao, Philipines to Southeast Pacific, 

Mongolia to Panama,

Los Lagos Chile to Greece, Croatia, Alaska Peninsula, Dodecanese Islands, 

Dodecanese Islands to South Shetland Islands, Los Lagos, Chile, 

Atacama  Chile to eastern Turkey, Andreanof Islands,

Alaska Peninsula to San Juan, Argentina, Balleny Islands, Mid-Indian Ridge, Aisen, Los Lagos, Chile,

Oaxaca Mexico to New Guinea, Turkmenistan,


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


Mindanao, Philipines to Central California, Idaho,

Mongolia to Kermadec Islands, Guerrero, Mexico, 

Los Lagos Chile to Mayotte, Vancouver, Canada,

Dodecanese Islands to Gulf of California, Los Angeles, South Sandwich Islands, Guatemala, Mammoth Lakes, California, Southern Atlantic, South East Pacific Rise, Ecuador, South Sandwich Islands, Oaxaca, Mexico, Gulf of California, Guam, Nicaragua, Sinoloa, Mexico, Central California, Ecuador, Ceram Sea, Costa Rica, Banda Sea, Indonesia, South Sandwich Islands, Northern Peru, Chiapas, Oaxaca, Mexico, Guatemala, Southern, Central California, 

Atacama, Chile to Southeastern Alaska. Switzerland,  Nunavit, Canada, Ionian Sea, Sicily, Sudan, Malta,  Iceland, Loyalty Islands, Nunavut, Canada, Fiji, Southern Alaska, England, Vanuatu, Iceland, Cornwallis, Nunavit, Northwest Territories, Canada, 

Alaska Peninsula to Southeast Pacific, Sumatra,  Easter Island, South Island, New Zealand, Socotra, South of Sumatra, Owen Fracture Zone, Central Mid-Atlantic, Honduras, Sumatra, South Pacific, West Chile Rise, northern Chile, southern Peru, Java, Sumatra, South Island, New Zealand, New Guinea to Gulf of California, South of Africa, Utah, Wyoming, Idaho, Southern California,

Oaxaca Mexico to Dodecanese Islands, Crete, Honshu, Japan, South Island, New Zealand, Balleny Islands, Vanuatu, Russia, Crete, Western Turkey, Romania, South Island, New Zealand, Eastern Honshu, Japan, Solomon Island, , 


Node 4 (90 degrees)


Mindanao, Philipines to

Mongolia to

Los Lagos Chile to Northern California,

Dodecanese Islands to Southern Idaho, Oklahoma, Izu Is, Japan,   

Atacama  Chile to North, South Island, New Zealand, Kermadec Islands, Washington State,  

Alaska Peninsula to Flores, Canary Islands, Dodecanese Islands, Northern Peru, Banda Sea, Iran, Crete, Lebanon, Pakistan, Kermadec Islands, Canary Islands,

Oaxaca Mexico to Tristan da Cunha,  Poland, Southern Kermadec Islands, N.Z.,


Node 5 (72 degrees)


Mindanao, Philipines to

Mongolia to Mount Hood, Oregon, 

Los Lagos Chile to

Dodecanese Islands to Cape Province, South Africa, Southern Quebec,

Atacama  Chile to  Baja, southern  California,

Alaska Peninsula to Mindoro, Philippines, Samoa, Nicaragua, New Britain, Solomon Islands, Dominican Republic, Galapagos, Mindanao, Philippines, Fiji, England, Samoa, Philippines, New Guinea to Fox Islands, Xizang, China,

Oaxaca Mexico to Iceland, North Atlantic,


Node 6 (60 degrees)


Mindanao, Philipines to

Mongolia to Greece, Papua, 

Los Lagos Chile to Virgin Islands, Central Mexico,  

Dodecanese Islands to

Atacama  Chile to Alabama,

Alaska Peninsula to Vera Cruz, Oaxaca, Mexico

Oaxaca Mexico to Alaska Peninsula,


Node 7 (52 degrees)


Mindanao, Philipines to

Mongolia to Halmahera,

Los Lagos Chile to

Dodecanese Islands to Siberia,

Atacama  Chile to Oaxaca, Mexico, Central mid-Atlantic,

Alaska Peninsula to Siberia, Western Mexico, Iceland, Greenland Sea, Siberia, Mongolia, Jan Mayen Is, Vera Cruz, Oaxaca, Mexico, Pennsylvania, Greenland Sea, Quebec, North Carolina, New York, Izu Islands, Japan, Alabama, 

Oaxaca Mexico to Coquimbo, Atacama, Chile, Southeast Alaska, Northwest Territories, Canada,