The range of 60-70 decibels sound pressure level is about as loud as normal conversation in 1 meter distance.
Flammable, Radioactive Sinkholes. Lesser known in the mainstream media, however, is frackingâs link to massive sinkholes appearing overnight and leaking radiation across the nation.
Sinkholes and Blue Holes. A sinkhole, also known as a cenote, sink, sink-hole, shakehole, swallet, swallow hole, or doline (the different terms for sinkholes are often used interchangeably), is a depression or hole in the ground caused by some form of collapse of the surface layer.