How many foreshocks where there in Chile earthquake 2010 and when were they?

The magnitude 8.8 earthquake that struck Chile on February 27, 2010, was preceded by a series of foreshocks. According to the United States Geological Survey (USGS), there were at least 15 foreshocks with a magnitude of 4.5 or greater in the days and weeks leading up to the main event. The largest of these foreshocks occurred on February 24, 2010, with a magnitude of 6.0.