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)


Brazil to

Mindanao, Philippines to

Komandorsky Islands to South Sandwich Islands, 

South Sandwich Islands to Komandorsky Islands, Russia, 

Loyalty Islands to

Southern Alaska to South of Africa, 

Minahasa to

Venezuela to Sumba, Minahasa, Sumbawa, Java, Lombok, Indonesia, 

Fiji to

Lomboc, Indonesia to  Venezuela,


Outer shadow zone edge (141-148 degrees)


Brazil to Guam, Bonin, Volcano Islands, Japan, 

Mindanao, Philippines to Central Chile,

Komandorsky Islands to

South Sandwich Islands to

Loyalty Islands to Crete,

Minahasa to Buenos Aires, Argentina, Baja California, Central Chile, Oaxaca, Mexico, 

Venezuela to Taiwan, Solomon Islands, Bonin Islands, Papua New Guinea, 

Fiji to Central Mid-Atlantic, Romania, Central Turkey, England, 

Lomboc, Indonesia to Eastern Texas, Ohio, Kentucky, Guerrero, Mexico, Central Chile, Quebec, Canada, 


Node 3 (120 degrees)


Brazil to

Mindanao, Philippines to Oklahoma, South Sandwich Islands.  

Komandorsky Islands to

South Sandwich Islands to Molucca, Utah, Central California, Thailand, 

Loyalty Islands to Venezuela, Zimbabwe, Ontario, Arctic Ocean, 

Southern Alaska to Buenos Aires, Argentina,

Minahasa to Tristan de Cunha, Utah, Baja California, South Sandwich Is, 

Venezuela to Fiji, Hokkaido, Southern Kurils, 

Fiji to Guadeloupe, Puerto Rico, Virgin Is,

Lomboc, Indonesia to Central, northern California, 


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


Brazil to Crete, Andreanof Islands, Alaska, Fiji, Tonga, Kermadec Is, Uganda, 

Mindanao, Philippines to Southern, central California, Utah,

Komandorsky Islands to Trinidad, Northern Mid-Atlantic, Venezuela, 

South Sandwich Islands to Mississippi, Sumatra, Sicily, Italy, Central Vanuatu, Tennessee, 

Loyalty Islands to Mississippi, Central Chile, Nebraska, Central Colorado, Missouri, Tajikistan, Chiapas, Oaxaca, Mexico,  

Southern Alaska to Java, East Pacific Rise, North Island, New Zealand, Lombok, Indonesia, Northern Chile, South of Java, Nias, Sunda Strait, Indonesia, 

Minahasa to Antarctic-Pacific Ridge, British Colombia, Ionian Sea, Sicily, Coast of Oregon, Vancouver,

Venezuela to Ural Mts, Andreanof Is, Northern Kamchatka, South of Africa, 

Fiji to Argentina, Caribbean Sea, Georgia, northern Chile, Nepal, Colombia, Tennessee, Indian Ocean, East of South Sandwich Is, Peru, Missouri, Ecuador, Colombia, Panama, Cayman Islands, South Sandwich Is, Brazil, Peru, Chile, Kentucky, 

Lomboc, Indonesia to Bosnia, South Sandwich Is, South Shetland Is, Germany, Northern Alaska, Arctic Ocean, Albania, Alaska, Italy, Southern Atlantic, Scotia Sea, Greenland Sea, South Sandwich Islands, Gulf of California,


Node 4 (90 degrees)


Brazil to

Mindanao, Philippines to

Komandorsky Islands to

South Sandwich Islands to Australia,

Loyalty Islands to Rivello Gigedo Is, Southern Alaska, northern Baja California, Southern California,

Southern Alaska to Tonga/Fiji, Kermadec Is, Pakistan, Sulawesi,  Loyalty Islands, Banda Sea,

Minahasa to southern Alaska, Romania, Greece, northern Alaska

Venezuela to

Fiji to Southern Chile, Northern Alaska, Mexico, Guatemala,

Lomboc, Indonesia to


Node 5 (72 degrees)


Brazil to

Mindanao, Philippines to

Komandorsky Islands to New Brunswick, Mississippi, Central Vanuatu,

South Sandwich Islands to

Loyalty Islands to

Southern Alaska to Tajikistan,

Minahasa to South Indian Ocean, Iran, Ural Mts, 

Venezuela to South Shetland Islands, 

Fiji to Sunda Strait, Northern East Pacific Rise, Taiwan, Hokkaido, Fox Islands, Kurils, Near Islands, 

Lomboc, Indonesia to


Node 6 (60 degrees)


Brazil to Utah,

Mindanao, Philippines to Komandorsky Islands,

Komandorsky Islands to Mindanao, 

South Sandwich Islands to

Loyalty Islands to

Southern Alaska to Oaxaca, Mexico, Central Peru, Fiji, Banda Sea,  

Minahasa to

Venezuela to Kuril Islands, 

Fiji to Sumba, Minahasa, Australia, Mindanao, Philippines, 

Lomboc, Indonesia to Honshu, Southern Kuril Islands,


Node 7 (52 degrees)


Brazil to

Mindanao, Philippines to

Komandorsky Islands to Yellowstone,

South Sandwich Islands to

Loyalty Islands to Australia, Mindanao, 

Southern Alaska to Tokyo, Japan,

Minahasa to Loyalty Is,

Venezuela to Idaho, Texas, Yellowstone, Northern Colorado, 

Fiji to Mariana Is, Banda Sea,

Lomboc, Indonesia to Vanuatu, Macquarie Island, Honshu, Japan,