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)


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)


Alaska Peninsula to Mozambique, South Africa, 

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

Oaxaca Mexico to Flores Sea, Indonesia, Myanmar, Carlsberg Ridge, 

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

Northern Chile to 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)


Alaska Peninsula to Los Lagos, Chile,

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

Oaxaca Mexico to New Guinea, Turkmenistan,

South of Kermadec to 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)


Alaska Peninsula to Sumatra, South Pacific, West Chile Rise, northern Chile, southern Peru, Java, Sumatra, 

New Guinea to South of Africa, Utah, Idaho, Southern California,

Oaxaca Mexico to 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)


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

New Guinea to Juneau, Alaska, Vancouver,

Oaxaca Mexico to  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)


Alaska Peninsula to  Bismarck Sea, Solomon Islands, D'entrecasteaux Islands, Laos, Haiti, New Guinea, Taiwan,  Xizang, Philippines, Mindanao,

New Guinea to Fox Islands, Xizang, China,

Oaxaca Mexico to Iceland, North Atlantic,

South of Kermadec to 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)


Alaska Peninsula to Oaxaca, Mexico

New Guinea to Myanmar,

Oaxaca Mexico to Alaska Peninsula,

South of Kermadec to 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)


Alaska Peninsula to New York, Izu Islands, Japan, 

New Guinea to Kuril Islands, Sumatra, Andaman Islands, 

Oaxaca Mexico to 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,



Node 8 (45 degrees)


Alaska Peninsula to Honshu, Japan, Gulf of California, Texas, Oklahoma,  


Node 11 (40 degrees)


Alaska Peninsula to


Node 10 (36 degrees)


Alaska Peninsula to Los Angeles, California


Node 11 (32.7 degrees)


Alaska Peninsula to Central California, Mammoth Lakes, California, 


Node 12 (30.0 degrees)


Alaska Peninsula to


Node 13 (27.6 degrees)


Alaska Peninsula to


Node 14 (25.7 degrees)


Alaska Peninsula to Coast of Northern California