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)


Central Atlantic to

Dodecanese Is. to

Komandorsky Is. to

Auckland Is. to North Atlantic, 

Guatemala to

Near Islands to


Outer shadow zone edge (141-148 degrees)


Central Atlantic to

Dodecanese Is. to Auckland Islands, Loyalty Is., Greece,

Komandorsky Is. to

Auckland Is. to Greece, Crete, Western Turkey,

Guatemala to East, West Indian Ridge, Western Australia, Minahasa, East Timor, India, Celebes,

Near Islands to

Sumatra to Chile,


Node 3 (120 degrees)


Central Atlantic to

Dodecanese Is. to New Britain, 

Komandorsky Is. to Uganda, Northern Chile, Southern Peru, 

Auckland Is. to Yellowstone, Oklahoma, Western Montana, 

Guatemala to Kyushu, Botswana, Northern China, Uganda, Ryukyu Islands, Guam, Iran, New Guinea, Bismarck Sea,

Near Islands to Southern East Pacific,   Northern Chile, Southern Peru,


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


Central Atlantic to SE Alaska, India, Central, Northern California,  

Dodecanese Is. to Central Peru, Mariana Islands, Costa Rica, El Salvador, Southeast Indian Ridge, Guatemala, New Guinea, Costa Rica, Gulf of California, Central, eastern Mexico, Baja California,

Komandorsky Is. to Auckland Islands, Colombia, Central Atlantic Ocean, Ecuador, Barbados, 

Auckland Is. to Central Peru, Rat and Andreanof Islands, Fox Islands, Nepal, Gulf of California, Near Islands, Northeastern China, Kuril Islands, Komandorsky Islands, Southern California, Ecuador, Andreanof Islands, Western Mexico,  

Leyte Philippines to Montana, Mammoth Lakes, California,

Guatemala to Solomon Islands, Southern Mid-Atlantic, Vanuatu, Greece/Turkey,  Crete, Cook Strait, Loyalty Is, Hokkaido, Kurils, New Zealand, Honshu, Japan, Vanuatu, Western Turkey, Loyalty Islands, Crete, Southern Kurils,  

Near Islands to Ecuador, Peru,  

Sumatra to south of Alaska,


Node 4 (90 degrees)


Central Atlantic to Guerrero, Mexico, 

Dodecanese Is. to Andreanof Is, Vancouver, Kansas, Cuba, Yellowstone, Oklahoma, Washington, 

Komandorsky Is. to Tunisia, Costa Rica, Puerto Rico,

Auckland Is. to Honshu, Japan, 

Guatemala to Fiji, Italy, Tonga, South Sandwich Islands, Kamchatka, 

Near Islands to Dominican Republic, Puerto Rico, Haiti,


Node 5 (72 degrees)


Central Atlantic to

Dodecanese Is. to Quebec, Central Atlantic Ocean, New York,

Komandorsky Is. to Tonga, Michoacan, Mexico, Tennessee, Reykjanes Ridge, Pennsylvania, Georgia, Vanuatu, Banda Sea, Fiji/Tonga, Nova Scotia, Tennessee, Georgia,  

Auckland Is. to Mentawai, Indonesia,

Guatemala to Bering Strait, Iceland, Andreanof Islands, Pribilof Is, Madeira Islands, 

Near Islands to Georgia, Caucasus, Banda Sea, Vanuatu, Ohio, Iraq, Guerrero, Mexico,


Node 6 (60 degrees)


Central Atlantic to

Dodecanese Is. to Sichuan, China, 

Komandorsky Is. to Bismarck Sea, Mindanao, New Britain, New Guinea, Kansas, Eastern Canada, Iceland, Myanmar, China, Oklahoma, New Britain, 

Auckland Is. to

Leyte Philippines to Rat Islands, Alaska, 

Guatemala to Northern Mid-Atlantic, Los Lagos, Chile, Alaska, Hawaii

Near Islands to New Ireland, New Guinea, Oklahoma,


Node 7 (52 degrees)


Central Atlantic to

Dodecanese Is. to Central Mid-Atlantic,

Komandorsky Is. to Sichuan, China, Taiwan, Yellowstone, Central California, Nevada,

Auckland Is. to

Leyte Philippines to Kamchatka,

Guatemala to North Atlantic Ocean, Central Chile, SE Alaska,

Near Islands to Southern California,

Sumatra to Solomon, New Ireland,


Node 8 (45 degrees)


Central Atlantic to

Dodecanese Is. to

Komandorsky Is. to Taiwan,  Coast of Northern California,

Auckland Is. to New Ireland

Guatemala to Vancouver Is, Northern, Central Chile,

Near Islands to Hawaii, Northern California, Taiwan,