If there was even the remotest chance that human beings could trigger an earthquake along major subduction zones, we would be doing so on a regular basis.
Geolologists and geophysicists have been looking for ways to relieve the stress along fault lines for a long time in small, controlled earthquakes to prevent the "big one". There just is no way for us puny earthlings to do that.
What often triggers earthquakes in faults with high stress is the infiltration of water (a lubricant) after a rainy period. Explosive force on the surface will be mostly directed upward and outward, not down into the earth. That's why explosives are ineffective to trigger earthquakes.
Thanks. This will be part of my response. Much welcomed.