Seismologists keeping eye on Carson City

CARSON CITY — Nevada seismologists and emergency managers are monitoring an earthquake swarm in Carson City that has the potential to result in a major temblor.

But officials from the Nevada Seismological Laboratory at the University of Nevada, Reno stressed they can’t predict how the sequence of more than 120 minor quakes that began June 1 will play out or whether it will result in larger events.

The largest quakes of the swarm have been one of magnitude 2.9 on June 5 and two of magnitude 2.8 on Thursday and June 16. While each was followed by many smaller quakes, no injuries or major damage have been reported.

The activity is occurring more than five miles below ground on the southeastern edge of the capital city of 55,000.

Graham Kent, director of the seismological lab, said such quake swarms in Northern Nevada are not unusual.

“Based on the historical record of earthquakes in the region, as earthquake sequences progress, the probability of larger events that could be felt or that could potentially cause damaging ground shaking increases,” he said in a statement. “We’re working with state emergency managers, and are watching this closely so citizens can be informed and prepared.”

Ken Smith, associate director of the lab, said major quakes are always possible in Northern Nevada.

“This sequence of events is noteworthy and of concern in that it may be associated with the northern extent of the Genoa Fault Zone, a large range-bounding fault system capable of earthquakes of magnitude 7 and larger,” he said. “We cannot forecast or predict how this particular sequence of earthquakes will evolve or if there will be larger events.”

Nevada is the third most seismically ac- tive state, behind California and Alaska.

In 2008, a swarm of thousands of minor quakes rattled Reno over a threeplus-month period. Seismologists urged residents of Northern Nevada’s largest city to prepare for a bigger event after a 4.7 quake on April 25, 2008, the strongest in the swarm.

That quake caused Reno high-rise casinos to sway, swept store shelves clean, cracked walls in homes and dislodged rocks on hillsides. It also prompted some frazzled residents in the densely populated quake zone to spend nights outside in campers and trucks. But there were no reports of injuries or major damage.

Magnitude 3.9 and 3.6 quakes struck within a couple minutes of each other in Reno on June 8, 2008, and were preceded by 3.2 and 3.0 quakes. No major damage or injuries were reported after those quakes, either.

Reno’s last major quake measured 6.1 on April 24, 1914.