skyquake
n.— «Roughly a year after a series of bizarre rumbling was reported across the Magic Valley, similar incidents are being reported again in south-central Idaho and northern Nevada.…Often called “skyquakes,” the unexplained booms have become a regular occurrence worldwide in recent years, often coming in waves over the same area.» —“They’re baaack” by Nate Poppino Times-News (Twin Falls, Idaho) Mar. 15, 2009. (source: Double-Tongued Dictionary)