A second earthquake hit the San Francisco area around 8:16 p.m. local time on Thursday, sending a tremor through Oakland's City Hall Plaza, where Occupy Oakland protestors have camped out for over a week.

Rather than being alarmed, the already energized crowd cheered, according to Gavin Aronsen, an editorial fellow at Mother Jones who is covering the protests.

The city of Oakland has allowed the protestors to camp out in the area, officially named Frank H. Ogawa Plaza, but controversy regarding the treatment of reporters caused a rise in police presence. The group was then served with an eviction notice, which stated that safety, sanitation and health hazards overwhelmed the right for assembly.

In recent days, camp conditions and occupants' behavior have significantly deteriorated, and it is no longer manageable to maintain a public health and safety plan, the city said in the notice.

The city said that overnight occupation would no longer be tolerated, and the Plaza would be open from 6 a.m. to 10 p.m.

But Occupy Oakland remained undaunted and said it would fight to continue occupying the area, even comparing the movement to Thursday's earthquakes.

Our eviction notice comes after the recent mild earthquakes today, the group posted on Twitter. Our power is surging beneath with [sic] waiting to come to the surface.

The two earthquakes, measured at 4.0 and 3.9 magnitude, did minor damage, according to local television reports. Some items fell off shelves in homes, plaster fell from a local business and artwork was knocked askew.

Ironically, the two earthquakes occured on the same day as the 2011 Great California Shakeout, a widespread safety drill where participants practiced the drop, cover and hold on technique. More than 8.5 million people had registered to attend, said organizers. The state has not experienced a major disaster since the 6.7 magnitude Northridge quake in 1994, which killed 72 people and caused $25 billion in damage.

Thursday's earthquakes came near the 22nd anniversary of the 6.9 magnitutude San Francisco earthquake that killed 63 people during the 1989 World Series.