Reno Nevada - Earthquake Centrl with over 100 Earthquakes on Friday

Another earthquake in the Reno area has dumped cans off shelves, knocked pictures off walls and sent rocks off hillsides.

The temblor came late Friday night, a day after a quake caused high-rise casinos to sway and put visitors and residents on edge. There were no immediate reports early Saturday of injuries or major property damage.

The U.S. Geological Survey says the 4.7 magnitude temblor at 11:40 p.m. was centered six miles west of Reno near Mogul. That's where a swarm of more than 100 quakes rattled the area on Thursday. The biggest was a 4.2 event.

A 3.5 aftershock followed at 12:29 a.m. Saturday, the USGS said.

The initial quake was felt 30 miles north in Portola, Calif., and at least 45 miles south near Stateline, Nev.

-----------------------------------------
Earlier report
-----------------------------------------

The growing magnitude and frequency of recent earthquakes in the Reno area make it hard for some experts to predict upcoming temblors, officials said Friday.

"We're not in the position to tell the future on this one," Glenn Biasi, a research associate professor at the University of Nevada, Reno Seismological Laboratory. "We were thinking that it would die down ... but to have those two earthquakes (Thursday) kind of put that exclamation point on it. We might not be done with it."

Biasi said large earthquakes usually are followed by smaller aftershocks. The Reno-area earthquakes in the past month reversed the pattern because they grew in magnitude over time.

"I think the message here is to be prepared," said Ken Smith, a research associate professor at UNR's Seismological Laboratory, who was among emergency management officials at a press conference Friday about preparedness. "Because we can't predict (earthquakes) and we can't prevent them."

On Friday, almost 100 earthquakes -- most under a 3.0 magnitude, were reported in the Reno area. The strongest temblor, a 3.6 magnitude, came about 6:15 p.m. Friday and rattled Northwest Reno.

In the past month, Smith cited several earthquakes that were between a magnitude 3 and 3.6. The strongest earthquake, at 4.2 magnitude, hit at 3:55 p.m. Thursday and was centered about four miles northwest of Reno, the U.S. Geological Survey said. At 3:47 p.m. Thursday, there was a 4.1 quake.

"If anything else, these earthquakes we've had just serve as a reminder that now is a good time to get (prepared)," said Aaron Kenneston, emergency manager of Washoe County.

Smith said he would call these recent quakes a "swarm." If these tremors were to lead to a larger earthquake, the set of rumbles would then be classified a "foreshock."

To prepare for any future quakes, Kenneston said residents should store in their homes items such as food, batteries, flashlights, first aid supplies and at least a gallon of water per family member. He said these items are useful in the event of any hazard.

"We found it makes a lot more sense to prepare for all hazards than it is to prepare just for an earthquake," Kenneston said.

Gary Derks, the operations officer for the Nevada Division of Emergency Management, said the state is ready to help Washoe County in the event of any catastrophe.

"If something were to occur, there is absolutely no doubt that the Division of Emergency Management is prepared to give assistance to local governments," Derks said.

Derks said the state has worked with various county and state entities to discuss a response plan. For example, in case of an earthquake, the Nevada Highway Patrol and the Nevada Department of Transportation would help check freeways and bridges for damage.

Washoe County and its cities and towns are constantly preparing for 13 types of disasters, from earthquakes and bio-infectious agents to hazardous materials accidents, Kenneston said.

Plans include participation with other local agencies and a chain-of-command so the agencies are working as a single unit.

District schools also are prepared for an earthquake, officials said.

Dale Sanderson, capital projects and facilities management administrator, said all district schools except one have a steel-reinforced wall system, "which is what you need in an earthquake."

Robert Mitchell Elementary School's roof is supported by an additional structural system made of wood. The school is the most vulnerable to an earthquake, but the reinforced system would help avoid a "catastrophic collapse of the building," Sanderson said.

The district has $100 million coverage for earthquake damage, and students also practice evacuation procedures each month. Some schools practice drills in class and ask students to seek shelter under their desks, said Chris Smith, district emergency management director.