The range of 60-70 decibels sound pressure level is about as loud as normal conversation in 1 meter distance. The distance from the ears to the sound source is very important to the value of the SPL. Scroll down to related links and look at Table of Sound Pressure Levels.
1 Primarily, during the fracking process:  [Earthquakes] were caused by fluid injection during hydraulic fracturing in proximity to pre-existing faults.. 2  Secondarily, via the disposal of fracking wastewater via underground injection.
Earthquakes and sinkholes in North Texas fracking zone described at meeting. Watch this news report about the peopleâs frack quake meeting last night in Azle and be horrified by, not only the earthquake damage but, the fracking sinkholes! The sinkhole in the news story is very near Traceyâs home.