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)


Qinghai, China to Central Chile, 

Fox Islands to  South of Africa, 

Flores Sea to Barbados, Greenland,

Timor  Sea to

Northern Peru to

Vanuatu to


Outer shadow zone edge (141-148 degrees)


Qinghai, China to South Sandwich Islands, Ecuador, Peru.

Fox Islands to Zimbabwe, South Indian Ocean, 

Flores Sea to Maine, Argentina, Galapagos Is, Atacama Chile, Northern Mid-Atlantic, Massachusetts, South Carolina, Kentucky, Alabama, Central Chile, Guatemala, Chiapas, Mexico, 

Timor  Sea to Maine, Argentina, Galapagos Is, Atacama Chile, Northern Mid-Atlantic, Massachusetts, Azores, Nicaragua, South Carolina, 

Northern Peru to Irian Jaya, Carlsberg Ridge, Korea, Bali, Ryukyu Islands, Xinjiang, China, Papua New Guinea, Gujarat, India, 

Vanuatu to  Cypress, Netherlands, Scotland, Turkey, Eastern Mediterranean, Northern Mid-Atlantic, Sicily, Italy, England, Crete,


Node 3 (120 degrees)


Qinghai, China to Michoacan, Mexico, Virgin Islands,

Fox Islands to Central Chile, 

Flores Sea to Southeast Pacific, Montana, Utah, Gulf of California, Southern, Baja California, Montana,  

Timor  Sea to Southeast Pacific, Wyoming, Southern California,

Northern Peru to Fiji, Iran, Mayotte, Solomon Islands, 

Vanuatu to Maine, Dominican Republic, Southern Iran, 


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


Qinghai, China to Baja California, South Pacific Ocean,  South, North Island, New Zealand, Tennessee, Southeastern Alaska, Gulf of California,  Kermadec Islands, Southern California,  

Fox Islands to South Island, New Zealand, 

Flores Sea to Antarctica, Greenland Sea, Greece, South Sandwich Islands, Eastern Alaska, 

Timor Sea to  Northern Greece, Yukon Canada, Southeastern Alaska, Antarctica, Vancouver, Sea to Crete, Greece,  Romania,

Northern Peru to Kermadec, Tonga/Fiji Islands, Northern Greece, South Africa, South Island, New Zealand, Andreanof, Rat Islands, Near Islands, Crete, Cook Strait, New Zealand, Fiji Islands, Prince Edward Islands, Greece, Macquarie Islands, New Zealand, Rat Islands, South Africa, Greece, Romania, Dodecanese Islands, South Island, New Zealand, 

Vanuatu to South of Africa, Carlsberg Ridge, Central Peru,  Atacama, Chile, Nicaragua, South Sandwich Islands, Mid-indian Ridges, Kansas, northern Chile, Louisiana, South of Africa, Ecuador, Iran, Nicaragua, South Georgia, South Indian Ocean, South Atlantic, Molucca Sea, Southern Peru, Hnduras, Costa Rica, South Sandwich Islands, Prince Edward Is, Indian Ocean, Brazil, Northern Chile, Oklahoma, Nicaragua, Central Chile, Guerrero, Mexico, Tajikistan, Scotia Sea, Veracruz, Mexico, South of Africa, Afghanistan, Oklahoma, Hindu Kush, Guatemala, South Sandwich Islands, Gujarat, India, 


Node 4 (90 degrees)


Qinghai, China to Tonga, 

Fox Islands to  Pakistan, Iran, Java, 

Flores Sea to Alaska Peninsula,

Timor  Sea to Southern Alaska, Georgia, 

Northern Peru to

Vanuatu to Xinjiang, China, Gulf of California, Southeast Asia, 


Node 5 (72 degrees)


Qinghai, China to Southeast Alaska, Northwest Territories, Canada, 

Fox Islands to New Guinea, Tonga, Fiji, 

Flores Sea to

Timor  Sea to Komandorsky Islands, Near Islands,

Northern Peru to British Columbia, Canada,


Node 6 (60 degrees)


Qinghai, China to Austria, Papua New Guinea, Northern Greece, Fox Islands, 

Fox Islands to Taiwan, Iceland, Greenland,   

Flores Sea to Tonga, Fiji,  Kashmir,

Timor  Sea to Kermadec Islands, Tonga, North Island, New Zealand, 

Northern Peru to western Montana, Geysers, California,  

Vanuatu to Halmahera, Central Honshu, Hokkaido, Taiwan, 


Node 7 (52 degrees)


Qinghai, China to

Fox Islands to Gulf of California, 

Flores Sea to Timor, South, North Island, New Zealand,  India, Nepal, Vanuatu,

Timor  Sea to Sea of Japan, India, Qinghai, China, South Island, New Zealand, 

Northern Peru to Northern Mid-Atlantic, Quebec, northern Gulf of California, 

Vanuatu to Flores Sea, Hawaii, Western Australia, Halmahera,