 Scientists with the USGS and UC Berkeley had predicted, with a 90 to 95% confidence level, that an earthquake would strike the Parkfield area between 1985 and 1993.This was known as the Parkfield Earthquake Prediction and the Parkfield Earthquake Experiment, conducted by the USGS.Attempts at predicting the quake continued until January 2001, but an earthquake of 5.5 magnitude or greater did not occur from 1985 until the 2004 quake.