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)


Mid-Atlantic to Papua New Guinea, 

Atacama  Chile to

Banda Sea to

Sumatra to south of Costa Rica, Panama, Colombia, 

Samar Philippines to

Alaska Peninsula to South of Africa, 

New Guinea to

Oaxaca Mexico to

South of Kermadec to Algeria, 

Northern Chile to

Banda Sea to

Northern Kuril Islands to South Sandwich Islands, 


Outer shadow zone edge (141-148 degrees)


Mid-Atlantic to northern Philippines, Honshu, Japan,   

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

Banda Sea to Chiapas, Mexico, Atacama, Chile,

Sumatra to New Jersey, Coquimbo, Atacama, Chile, Gulf of California, Arkansas, Michigan, Oklahoma, Texas, western Mexico, Central Chile, 

Samar Philippines to Puerto Rico, Costa Rica,  

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

New Guinea to Northern Atlantic, Southern Atlantic, Puerto Rico, 

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

South of Kermadec to Caucasus, Iraq, Iran, Iceland, Northern Mid-Atlantic, 

Northern Chile to Honshu, Japan, Tajikistan, Gujarat, India, 

Banda Sea to Northern Chile,  Central Peru, 

Northern Kuril Islands to Argentina, Southern Mid-Atlantic, Maule, Aisen, Chile, 


Node 3 (120 degrees)


Mid-Atlantic to Andaman Islands,

Atacama  Chile to eastern Turkey, Andreanof Islands,

Banda Sea to Falkland Is, Baja California, 

Sumatra to

Samar Philippines to Madeira Islands, Quebec,

Alaska Peninsula to Los Lagos, Chile,

New Guinea to Arkansas, Crete, Chiapas, Oaxaca, Mexico, Western Turkey, Iceland,  

Oaxaca Mexico to New Guinea, Turkmenistan,

South of Kermadec to New Jersey, Martinique, Caribbean, Pakistan, Ontario, Quebec, Canada, 

Northern Chile to Northeastern Turkey, Andreanof Is, ` 

Banda Sea to Baja California, Mexico, 

Northern Kuril Islands to Chile Rise, 


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


Mid-Atlantic to mid-Indian Ridge, China, Tajikistan, Southern Alaska,

Atacama, Chile to  Loyalty Islands, Nunavut, Canada, Fiji, Southern Alaska, England, Vanuatu, Iceland, Cornwallis, Nunavit, Northwest Territories, Canada, 

Banda Sea to Greece, Southeastern Alaska, Bouvet Is, 

Sumatra to Southern Alaska, England, Hawaii, South Sandwich Islands, Tristan da Cunha, Pacific-Antarctic, Jan Mayen, Iceland, Alaska Peninsula, Hawaii, South Sandwich Islands, 

Samar Philippines to Idaho, Central, Southern, northern  California, South of Africa,  

Alaska Peninsula to 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 Crete, Honshu, Japan, South Island, New Zealand, Balleny Islands, Vanuatu, Russia, Crete, Western Turkey, Romania, South Island, New Zealand, Eastern Honshu, Japan, 

South of Kermadec to  Northwest Territories, Canada,, Myanmar, Panama, Mongolia,  Alabama, Alberta, Montana, Northern, central  Alaska, Myanmar, Oklahoma, Utah  

Ryukyu Is to Maine, North Atlantic, New Mexico,

Northern Chile to Bosnia, Kodiak, Alaska, Poland, Fiji, 

Banda Sea to Off Northern California, Sweden, Vancouver, 

Northern Kuril Islands to South of Australia, Puerto Rico, Northern Mid-Atlantic, Mid-Indian Ridge, Kenya, Dominican Republic, Puerto Rico, Northern Mid-Atlantic, 


Node 4 (90 degrees)


Mid-Atlantic to Los Angeles, California,

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

Banda Sea to  Eastern Turkey, Alaska,

Sumatra to

Samar Philippines to

Alaska Peninsula to Banda Sea, Iran, Crete, Lebanon, Pakistan, Kermadec Islands, Canary Islands,

New Guinea to Juneau, Alaska, Vancouver,

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

South of Kermadec to Alaska Peninsula, Central Chile, Oaxaca, Mexico, Mammoth Lakes, Lone Pine, Ridgecrest, California, Western Nevada, Sumatra, 

Northern Chile to

Banda Sea to Southern Alaska,

Northern Kuril Islands to Oaxaca, Mexico, Gulf of Aden, Red Sea, North Atlantic, Algeria, South, North Island, New Zealand, Chiapas, Oaxaca, Guatemala, 


Node 5 (72 degrees)


Mid-Atlantic to

Atacama  Chile to  Baja California,

Banda Sea to

Sumatra to Loyalty Islands, NW of New Zealand, eastern Turkey, 

Samar Philippines to

Alaska Peninsula to Galapagos, Mindanao, Philippines, Fiji, England, Samoa, Philippines, New Guinea to Fox Islands, Xizang, China,

Oaxaca Mexico to Iceland, North Atlantic,

South of Kermadec to South Shetland Is, Java,  Samar, Panay, Philippines, 

Northern Chile to Ridgecrest, California, 

Banda Sea to

Northern Kuril Islands to India, Ontario, Central East Pacific Rise, Quebec, Oklahoma, Kansas, Bali, Indonesia,


Node 6 (60 degrees)


Mid-Atlantic to Crete,

Atacama  Chile to Alabama,

Banda Sea to Kermadec,

Sumatra to

Samar Philippines to

Alaska Peninsula to Vera Cruz, Oaxaca, Mexico

New Guinea to Myanmar,

Oaxaca Mexico to Alaska Peninsula,

South of Kermadec to Banda Sea, Micronesia,

Northern Chile to

Banda Sea to

Northern Kuril Islands to Tajikistan, Utah, Southern California, India, Central Indonesia, Mammoth Lakes, California,  


Node 7 (52 degrees)


Mid-Atlantic to

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

Banda Sea to

Sumatra to New Britain,

Samar Philippines to

Alaska Peninsula to Pennsylvania, Greenland Sea, Quebec, North Carolina, New York, Izu Islands, Japan, 

New Guinea to Kuril Islands, Sumatra, Andaman Islands, 

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

South of Kermadec to

Northern Chile to

Banda Sea to Macquarie, Kermadec, South, North Island, New Zealand, 

Northern Kuril Islands to Halmahera Indonesia,