FAIRBANKS, Alaska (AP) _ A moderate earthquake shook the Fairbanks area Friday evening. There were no reports of damage.

The quake occurred at 6:50 p.m. and had a preliminary magnitude of 5.0 on the Richter scale, said Jim Dickson at the the University of Alaska Fairbanks Geophysical Institute. It was centered 33 miles southwest of Harding Lake.

The quake was felt at the university and other areas in and around the city.

The Richter scale is a measure of ground motion as recorded on seismographs. Every increase of one number means a tenfold increase in magnitude. Thus, a reading of 7.5 reflects an earthquake 10 times stronger than one of 6.5.

An earthquake at 5.0 on the scale is capable of causing considerable damage.