Terrestrial weaponization

[Image: From a simulation of nuclear bunker buster technology, produced by the Union of Concerned Scientists].

Defense Tech introduces us to the "earthquake array," a "focused underground shockwave that amounts to an artificial earthquake." This "artificial earthquake" will be put to use by the Air Force, of all people (not the Earth Force?), in order to annihilate underground targets.
Intriguingly, the shockwave will cause all regional tunnels, bunkers, mines, sewers, nightclubs, basement TV rooms, commercial show caves, etc., to collapse – which means that the bomb is actually a kind of landscape weapon, de-caving the earth from within.
"The secret," we read, "is in effectively combining 20 separate explosions into a coherent pulse."
More interesting than explosives, however, would be the phenomenal amount of patience and long-term thinking required to execute a slightly different plan: seeing that the future rise of a distant empire is all but historically inevitable, you and a crack team of undercover geotechnical engineers go deep into what will soon be enemy territory – even if not for another 500 years – and you install several hundred acres of massive vibrating plates a thousand feet below ground. You hook them up to something – perhaps a geothermal well – and then you landscape the hell out of the place.
No one will know you were there.
Then 500 years goes by, at which point that distant empire is now your biggest rival – and that means your moment has come. Your weapon is ready.
You activate the earth-plates.
Within seconds, a shuddering manmade tectonic groan of undeclared, anti-architectural, vibrational warfare levels their whole civilization. Your plan works.
It's the earthquake array, as it really should be. Terrestrial weaponization. Earth War I.

(For quite similar thoughts, involving James Bond, see BLDGBLOG's guide to tectonic warfare).