Reno

Late Friday night Mogul, NV (just west of Reno) was struck by a M4.7. While a M4.7 earthquake is not terribly large, it was a very shallow quake causing items to fall off grocery shelves, minor rock falls in the surrounding hills, and some of the taller casinos to sway. This quake is the largest thus far in a swarm that began approximately two weeks ago causing seismologists at University of Nevada Reno to issue a statement warning residents of a heightened probability of a larger earthquake.

Source: University of Nevada Reno.

Following an earthquake of this size there is a small increase in the probability of a larger magnitude earthquake in the west Reno area. Citizens should also be aware of the possibility of strong aftershocks from this evenings Magnitude 4.7. Mogul-Somersett residents should expect to feel aftershocks of this earthquake for some time. It cannot be determined if this evenings Magnitude 4.7 earthquake will be the largest earthquake of the 2008 Mogul-Somersett earthquake sequence

The Seismological Laboratory at UNR has posted some terrific products related to this swarm which can be found on their website. The graph below shows clearly how the recent swarm is not just background noise but a true signal:

Source: University of Nevada Reno.