People standing around would suddenly find the Earth moving at a thouand miles per hour beneath their feet. They would fall down and be tumbled over and over to their deaths. Most structures (and trees) would probably fall down and join a 'tidal wave' of debris. The oceans would slosh out of their banks, to some, probably very large, degree of calamity. Planes in the air might be OK for a while, but serious atmospheric phenomena would surely soon(?) occur. Should you suspect this might soon happen, my lay opinion is that you should go to near the North or South pole, and lie down. An interesting question would be how near a pole you would have to be to survive in the short term.
