The Reno earthquakes of 2008, also known as the "Mogul-Somersett earthquake sequence", occurred in or near the western Reno, Nevada, suburbs of Mogul and Somersett. The earthquake swarm began in February 2008, but the first significant quake of the series occurred on April 15, 2008, registering a 3.6 magnitude. On April 24, 2008, two quakes in the same area registered 4.1 and 4.2. On April 25, 2008, the quake of largest magnitude occurred, registering 4.7 on the Richter scale and causing damage in the immediate area around the epicenter, including destroying 200 feet (61 m) of a wooden flume supplying water from the Highland Ditch, also known as the Highland Ditch flume. The flume carried up to 50 million US gallons (190,000 m3) a day from the Highland Ditch to Reno's Chalk Bluff Water Treatment Facility and another 5 million US gallons (19,000 m3) to area irrigation users.
In the early morning hours of August 16, 1931, a powerful earthquake occurred in West Texas with a maximum Mercalli intensity of VIII (Severe). Estimates of its magnitude range between 5.8–6.4 mb, making it the most powerful earthquake ever recorded in Texas history. Its epicenter was near the town of Valentine, Texas; there, the earthquake caused damage to many homes and buildings. The earthquake may have been caused by movement along oblique-slip faulting in West Texas, the most seismically-active region in the state. Shaking from the earthquake was perceptible within a 400 mi (640 km) radius of the epicenter, affecting four U.S. states and northern Mexico. Several foreshocks and aftershocks accompanied the primary temblor, with the aftershocks continuing until at least November 3, 1931. The main earthquake caused no fatalities, though several people sustained minor injuries; the damage in Valentine amounted to $50,000–$75,000.
The 1986 Chalfant Valley earthquake struck southern Mono County near Bishop and Chalfant, California at Pacific Daylight Time on July 21. With a moment magnitude of 6.2 and a maximum Mercalli intensity of VI (Strong), the shock injured two people and caused property damage estimated at $2.7 million in the affected areas. There was a significant foreshock and aftershock sequence that included a few moderate events, and was the last in a series of three earthquakes that affected southern California and the northern Owens Valley in July 1986.
The Oklahoma earthquake swarms are an ongoing series of human activity-induced earthquakes affecting central Oklahoma, southern Kansas, northern Texas since 2009. Beginning in 2009, the frequency of earthquakes in the U.S. state of Oklahoma rapidly increased from an average of fewer than two 3.0+ magnitude earthquakes per year since 1978 to hundreds each year in the 2014–17 period. Thousands of earthquakes have occurred in Oklahoma and surrounding areas in southern Kansas and North Texas since 2009. Scientific studies attribute the rise in earthquakes to the disposal of wastewater produced during oil extraction that has been injected more deeply into the ground.
The 2019 Ridgecrest earthquakes of July 4 and 5 occurred north and northeast of the town of Ridgecrest, California located in Kern County and west of Searles Valley. They included three initial main shocks of magnitudes 6.4, 5.4, and 7.1, and many perceptible aftershocks, mainly within the area of the Naval Air Weapons Station China Lake. Eleven months later, a Mw 5.5 aftershock took place to the east of Ridgecrest. The first main shock occurred on Thursday, July 4 at 10:33 a.m. PDT, approximately 18 km (11.2 mi) ENE of Ridgecrest, and 13 km (8.1 mi) WSW of Trona, on a previously unnoticed NE-SW trending fault where it intersects the NW-SE trending Little Lake Fault Zone. This quake was preceded by several smaller earthquakes, and was followed by more than 1,400 detected aftershocks. The M 5.4 and M 7.1 quakes struck on Friday, July 5 at 4:08 a.m. and 8:19 p.m. PDT approximately 10 km (6 miles) to the northwest. The latter, now considered the mainshock, was the most powerful earthquake to occur in the state in 20 years. Subsequent aftershocks extended approximately 50 km (~30 miles) along the Little Lake Fault Zone.
On May 15, 2020 at 4:03:27 local time, a magnitude 6.5 earthquake struck ~35 miles (56 km) west of Tonopah, Nevada in the Monte Cristo Range near the California-Nevada border. It was Nevada's largest earthquake in 66 years.
The 1962 Cache Valley earthquake was a magnitude 5.9 earthquake that occurred on Thursday, 30 August 1962 at approximately 6:35 AM MT north of Richmond, Utah, United States, at the border between Utah and Idaho. No people were killed in the quake. The quake caused between US $1–2 million in damage.
In 1954, the state of Nevada was struck by a series of earthquakes that began with three magnitude 6.0+ events in July and August that preceded the Mw 7.1–7.3 mainshock and M 6.9 aftershock, both on December 12. All five earthquakes are among the largest in the state, and the largest since the Cedar Mountain earthquake of 1932 and Pleasant Valley event in 1915. The earthquake was felt throughout much of the western United States.
