So, let's see...a tank circuit hooked to sensors at a resonant frequency of multiples of .0005 Hz...and the earth drives our generators for us. Better than catching a tornado and putting it in a box. 'Course if it really caught on, every home would be run by one in the basement, there would be millions of these boxes all over Earth...and the feedback would interfere with the original oscillation beat and degrade it or reinforce it and it would be worse than global warming. We'd get Global Humming! Every hearing species on earth would go psycho, and only the cockroaches survive...

There is actually a legendary tale that Nikolai Tesla caused earth-tremors in the lower Village of Manhattan by using a resonator which fed back a pulse into the bedrock through an iron columnin his workshop, which made the neighborhood start to oscillate, and the local constables figured it had to do with him and found him toying with this device in his warehouse/workshop. Made him quit it.

Dunno if its true or not, but a funny story and a cautionary tale about what happens when oscillations feed back into themselves. Remember Gallopin' Gertie, the Tacoma Narrows bridge that tore itself apart back in the (?) 20's? Same principle...