Recent studies have shown that the ground rose noticeably before the 1971 San Fernando quake that killed 58 people in California's last major trembler.
When the bomb hit the ground, the shock worked a "trembler switch" that touched off the bomb's main charge.
Small quake shakes Blowing Rock A micro-earthquake hit about 2 miles north-northeast of Blowing Rock, N.C., on Sunday afternoon, Aug. 25, according to the U.S. Geological Service. A USGS report said the 2.9-magnitude trembler occurred at 2:50 p.m. There were no reports of damages. The hypocentral depth of the quake was about 6 miles. Earlier Sunday, residents of Glen Falls, N.Y. (near Albany) experienced a 2.7-magnitude quake ...
Aug. 27, 2013 - Mountain Xpress