An earthquake swarm that began in a secluded northwest Nevada region this summer has grown more intense in recent days, increasing the chance of a large quake occurring, geology officials said.
The activity is centered just off the state's northwest border, some 40 miles (64 km) southeast of Lakeview, Oregon, and started July 12, the Nevada Seismological Laboratory said on Wednesday.
Over the past three months, the laboratory has recorded some 550 incidents of seismic activity of a magnitude of 2.0 or larger, while there have been three magnitude 4.0 or higher quakes since Oct. 30.
On Tuesday, the area was rocked by a magnitude 4.6 earthquake, the laboratory said.
The U.S. Geological Survey said that roughly a dozen quakes between magnitude 2.5 and 3.6 shook the area on Friday.
The laboratory said that following swarms like these there is a slight increase in the likelihood that a larger earthquake will happen.
The current swarm resembles one that occurred in Reno, Nevada, in 2008 that shook the area over a two-month stretch with increasingly strong temblors leading to a magnitude 5 quake that caused moderate damage in the area, the Laboratory said.
(Reporting by Curtis Skinner; Editing by Hugh Lawson)