The earthquake happened in an area where earthquakes are something common, USGS said.
The epicenter of the earthquake was located at 10 km from Weitchpec, a city close to the Six Rivers National Forest, not far from the Oregon border.
Authorities say that no damages or victims were recorded.
To measure the magnitude of an earthquake, USGS uses the “moment magnitude” scale. On this open scale, a 6 magnitude earthquake is considered powerful.
The North of California is frequently affected by earthquake, and the intense seismic activity is due to the San Andreas strip, who crosses the most populated state in the United States.
Seismologists estimate that there is a 99% probability for a devastating earthquake to hit California in the next 30 years. According to estimates, a 7,8 magnitude earthquake might kill 1,800 people, 50,000 might suffer injuries and it might damage 300,000 buildings.
In 1994, a 6,7 magnitude earthquake hit Los Angeles and it killed 60 people, it caused damages worth 10 billion dollars. Five years earlier, 67 people died in San Francisco because of a 6,9 magnitude earthquake.