This is an animated map of seismicity in North Texas and Southern Oklahoma, showing the drastic increase in activity as a result of waste water injection, part of the hydraulic fracturing process. Earthquakes are symbolized by circles that are proportional to the magnitude of that earthquake. The circles appear green before the onset of hydraulic fracturing activity, and red after. The increase begins around 2008. Each time an earthquake occurs, a sound made of a sped up seismogram is played. I suggest you keep the volume low, because it turns out seismograms sound like thunder or shotgun blasts when they are sped up!