Based on earlier research of my own, it seems that either Haarp is used to deflect CME's or is used to directly counter the energy wave frequency given off by an earthquake. I'll explain each briefly below.

Haarp as CME deflector: During the midwest tornado outbreak, the planet was being bombarded by CME's. It may be that CME's cause earthquakes because there is some correlation between large scale earthquakes and CME's. Haarp usually gets cranked up during these solar storms which leads me to believe that it may be used to deflect the CME's and keep them from directly striking fault areas. The CME appears to bounce around the earth and eventually cause an earthquake elsewhere on the planet.

Haarp as earthquake preventer: During the midwest tornado outbreak, it was reported that a frequency similar to an earthquake registered over the New Madrid fault. However, it did not emimate from the fault itself, it seemed to come from the tornados. In other words, the tornados were creating an energy wave similar to that given off by an earthquake. This leads me to believe that Haarp may be used to create storms that actually counter the harmonics of the fault which result in a cancellation of the earthquake energy waves and a subsequent elimination of the earthquake.

At this point, it is all speculation. My guess is as good as any. I'm just trying to piece it all together.