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)


Solomon Islands to

Sumatra to South of Panama, 

Tonga to

Fiji to

Panama to South of Sumatra, Indonesia, 

Michoacan, Mexico to

Taiwan to

New Guinea to

Central Mid-Atlantic to New Britain,

Sichuan, China to Central Chile, Central East Pacific, 

Luzon, Philippines to

Southern Peru to Vietnam, 

Loyalty Islands to

Sumatra to Colombia,


Outer shadow zone edge (141-148 degrees)


Solomon Islands to Azores, 

Sumatra to New Mexico, Central Chile, Missouri, Oklahoma, northern Mexico, Gulf of California, Texas, Illinois, Valparaiso, Chile, 

Tonga to Turkey, Azores, northern Mid-Atlantic,  Reykjanes Ridge,

Fiji to Azores, Turkey,  Mid-Atlantic, Reykjanes Ridge, 

Panama to Northern India, Banda Sea, Halmahera, Luzon, Samar, Philippines,

Michoacan, Mexico to Owen Fracture Zone, Sumatra, 

Taiwan to Venezuela, Panama, Colombia, Southern Atlantic, South Sandwich Islands,

New Guinea to Portugal, Dominican Republic, Mid-Atlantic, Azores, northern Atlantic, 

Central Mid-Atlantic to Izu Islands, Japan, Kermadec Islands, Mindanao, 

Sichuan, China to South of Panama, Colombia, East Pacific Rise,

Luzon, Philippines to South of Panama, Central Mid-Atlantic, Dominican Republic, Puerto Rico, West Chile Rise, Southern Chile, Central Mid-Atlantic, Puerto Rico, Nicaragua, Dominican Republic, 

Southern Peru to Papua, Guam, Izu,  Bonin Islands, Honshu, Japan, Mariana Is, Papua New Guinea, 

Loyalty Islands to Reykjanes Ridge, Dodecanese Islands, Greece, Turkey, Poland, Ukarine, Cyprus, Bulgaria, North Macedonia, Bosnia and Herzgovina, Eastern Mediterranean, Crete, Black Sea, Northern, Central Mid-Atlantic, Poland, Bulgaria, Turkey, 

Honshu Japan to Ascension Island, Peru, Tarapaca, Chile, 


Node 3 (120 degrees)


Solomon Islands to  Galapagos, Iceland, Ontario, New York, Panama, 

Sumatra to Central Mid-Atlantic, Vancouver, Alberta, Coast of Oregon,

Tonga to Greenland, Quebec, Tajikistan, 

Fiji to Nunavut, Quebec, Canada, Virgin Islands, Puerto Rico, 

Panama to Honshu, Japan, Solomon Islands,

Michoacan, Mexico to South of Australia, Tajikistan, Taiwan, 

Taiwan to Western Mexico, Georgia, 

Luzon, Philippines to Virginia, Southern Texas, Michoacan, Mexico, New Jersey, New York City, 

New Guinea to Iceland, Missouri, Bosnia, Illinois, Arkansas, Gulf of Mexico, Chiapas, Mexico, Iceland, Los Lagos, Chile,  

Central Mid-Atlantic to Fox Islands, Sumatra, Sichuan, China,

Sichuan, China to Central Mid-Atlantic, 

Southern Peru to Kuwait, Santa Cruz Is,

Loyalty Islands to Virginia, Haiti, New York State, Southern Iran,  

Honshu Japan to Panama, North Atlantic, Puerto Rico,


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


Solomon Islands to Southern Iran, Oaxaca, Mexico, Western Texas, 

Sumatra to Pacific-Antarctic Ridge, Hawaii, Jan Mayen, Norwegian Sea, South Sandwich Islands, Southern Alaska, Hawaii, Gibraltar, Beaufort Sea, Alaska, 

Tonga to South Carolina, Alberta, Beaufort Sea, South of Africa, Georgia, Illinois, Louisiana, British Columbia, Canada,  Central Chile, 

Fiji to Alberta, Northern Chile, South of Africa, Arkansas, Oklahoma, Chiapas, Mexico, Algeria,

Panama to Kuril Is, Fiji Islands, North Island, New Zealand,

Michoacan, Mexico to Aegean Sea, Mariana Islands, Turkey, Solomon Islands, Southern Honshu, Japan, South Sandwich Islands, Romania, South Island, New Zealand, Lake Baykal, South Atlantic, Mariana Is,  New Ireland, New Britain, Greece, South Island, New Zealand, Mariana Islands,

Taiwan to Pacific-Antarctic Ridge, Gulf of California, Reykjanes Ridge, Southern California,  Yellowstone National Park, Northern Mid-Atlantic, 

New Guinea to New Mexico, Easter Island, Alberta, Iran, Montana, Idaho, Nunavut, Canada, Gulf of California, Northwest Iran, Turkey, Baja California, Yellowstone, Wyoming, 

Central Mid-Atlantic to Coast of Northern California, Botswana, Central Alaska, Yukon, Vancouver, B.C.,  

Sichuan, China to northern, Central California, Quebec,  

Luzon, Philippines to Los Angeles, Gibraltar, Reykjanes Ridge, Yellowstone, Wyoming, Quebec, Idaho, Wyoming, Colorado, Pacific-Antarctic Ridge, South Africa, Central California, 

Southern Peru to Dodecanese Islands, Greece, Tanzania, Turkey, Svalbard, Pribilof Is, South Island, New Zealand, Alaska Peninsula, Fiji, South of Alaska, Unimak Island, Alaska, 

Loyalty Islands to Alberta, Guatemala, Nepal, Central Peru, Northwest Territory, Canada, South of Panama, Tajikistan, Southern Texas, Gulf of Mexico, El Salvador, Xinjiang, China, Nicaragua, Guatemala, Oklahoma, Western Texas, Mongolia, Southern Texas, Oaxaca, Bouvet Is, Carlsberg Ridge, Ecuador, Argentina, eastern Mexico, Kashmir, Nicaragua, Texas,  

Honshu Japan to Balleny Islands, North Atlantic Ocean, Oaxaca, Guerrero,  Mexico,


Node 4 (90 degrees)


Solomon Islands to Vancouver, Baja California, Easter Island, 

Sumatra to Italy, Andreanof Islands,

Tonga to Texas, Colorado, Idaho, Denali, Montana, British Columbia, Yukon Territory, Canada, Guatemala, Sichuan, China,  

Fiji to Vancouver, Texas, Anchorage, Alaska, northern Mexico, South Sandwich Islands, Michoacan, Mexico,  British Columbia, Canada, Guatemala, 

Panama to Tonga, Fiji, Italy,

Michoacan, Mexico to Fiji,

Taiwan to Coast of Northern California, Washington,

New Guinea to Yukon, Canada, 

Central Mid-Atlantic to Yellowstone, WY, Gulf of California, Afghanistan, 

Sichuan, China to Hawaii, Fiji, 

Luzon, Philippines to Iceland, France-Germany,

Southern Peru to England,  Hawaii, Iceland, 

Loyalty Islands to Vancouver, Gulf of California, Aysen, Chile, Southern Alaska, southern, central  California, Gulf of California, 

Honshu Japan to


Node 5 (72 degrees)


Solomon Islands to Pacific-Antarctic Ridge,

Sumatra to Kuril Islands,

Tonga to Baja California, Rat Islands, Fox Islands, Andreanof Islands, Kuril Islands,  South of Sumatra, Coast of Oregon, 

Fiji to Baja California, Fox Islands, Andreanof Islands,

Panama to Beaufort Sea, southern Alaska, southern mid-Atlantic,  Hawaii, Denali,

Michoacan, Mexico to  Iceland, Antofagasta, Chile,  

Taiwan to Beaufort Sea, Southern, Central Alaska, South Indian Ocean, Fiji, Tonga,

New Guinea to Nepal, Fox Islands, Alaska,

Central Mid-Atlantic to

Sichuan, China to South Indian Ocean, Tanzania,  Santa Cruz Is,

Luzon, Philippines to Fiji, 

Southern Peru to Northern California, 

Loyalty Islands to Easter Island,  Andreanof Islands, Sumatra, Kuril Islands, 

Honshu Japan to Iran, Tonga, Fiji, Central California, Idaho, Tonga, Southern Iran,


Node 6 (60 degrees)


Solomon Islands to  Sumatra, Kuril Islands, 

Sumatra to Solomon Islands,

Tonga to

Fiji to Easter Island, 

Panama to

Michoacan, Mexico to Fox Islands, Andreanof Islands, Reykjanes Ridge, Coquimbo, Chile, Fox Islands, Aleutians,  

Taiwan to Andreanof Islands, Alaska, Santa Cruz Islands, 

New Guinea to

Central Mid-Atlantic to

Sichuan, China to New Britain, 

Luzon, Philippines to Southern Iran, Andreanof Islands, 

Southern Peru to Maine, 

Loyalty Islands to Bonin Islands, 

Honshu Japan to Vancouver, 


Node 7 (52 degrees)


Solomon Islands to Kuril Islands, 

Sumatra to Southern Iran, Mariana Islands, Tajikistan, Hindu Kush, 

Tonga to South of Australia, Western Australia,

Fiji to Guam, Banda Sea,  Hawaii,

Panama to Northern mid-Atlantic,

Michoacan, Mexico to Northwest Territory, Canada, Kenai, Alaska,  northern Chile, Bolivia, 

Taiwan to Pakistan, Santa Cruz Is,

New Guinea to Sumatra, 

Central Mid-Atlantic to Northern Chile,  Colombia, Dominican Republic,

Sichuan, China to

Luzon, Philippines to Santa Cruz, Is,

Southern Peru to

Loyalty Islands to Hawaii, Sulawesi, Indonesia,

Honshu Japan to Nicobar Islands, Kashmir, Tajikistan,