This is interesting when you think about our HAARP at 2.5 today again.
[link to www.haarp.alaska.edu]

Thread: EQ Swarm in Cali. and HAARP emmits between 2.5Hz and 3Hz

[link to socioecohistory.wordpress.com]
What is the significance of a 2.5 Hz ULF broadcast? The natural resonance of an earthquake is 2.5 Hz. Scientists working for the United States military discovered this using the phased array antennas at the HAARP facility in Alaska. HAARP’s own charts suggests that earthquakes occurred constantly for 3 days. We know for a fact that they haven’t.