ABC is reporting
State of Emergency After Northern California Shaken by Biggest Earthquake in 25 Years
Northern California was shaken awake this morning by its strongest earthquake in 25 years, a jolt that damaged historic buildings and hurt dozens of people, including a young child who had to be flown out of the area for treatment after being critically injured by a crumbling fireplace.
California Gov. Jerry Brown declared a state of emergency after the South Napa Earthquake, which struck about 3:20 a.m. local time, according to the U.S. Geological Survey. Its epicenter was located about six miles south-southwest of Napa, California, and 51 miles west-southwest of the state capital, Sacramento. Officials have variously referred to the earthquake's magnitude as 6.0 and 6.1.
Dozens of aftershocks followed, with one reaching 3.6 magnitude, the USGS told ABC News. The earthquake was the largest one to shake the Bay Area since the 1989 6.9-magnitude Loma Prieta Earthquake.
Pacific Gas and Electric Company says more than 15,000 customers without power, and I imagine it must be important for people to check for gas leaks which should be reported immediately.
CNN reports this was a "slip plate fault."
9:57 AM PT: One NAPA valley hospital reports 70 injuries. No fatalities have been reported.
10:04 AM PT: Emergency declared after 6.0 earthquake sends 89 to hospital in Napa
A long, rolling 6.0 earthquake shook a wide swath of the Bay Area awake early Sunday, prompting Gov. Jerry Brown to declare a state of emergency. The temblor damaged buildings, cut off power to tens of thousands, sparked fires, and sent at least 89 people to a hospital including three who were in critical condition.
Centered about nine miles south of wine country's Napa at 3:20 a.m., the quake was felt as far south as Santa Cruz and into Sonoma County. It was the largest earthquake to strike the Bay Area since the 6.9 Loma Prieta temblor of 1989, the U.S. Geological Survey said.
The National California Seismic System put the chance of a strong aftershock in the next week at 54%. Scientists at UC Berkely released a video showing an early-warning system that sent an alert 10 seconds before the earthquake.
According to a PG&E map, more than 42,000 customers were without power across the northern Bay Area, including American Canyon, Napa, St. Helena, Santa Rosa and Sonoma.
Gov. Brown said full emergency services have been activated: "These public safety officials are doing all they can to help residents, and those living in affected areas should follow their guidance and instruction,” he said in a statement.
10:13 AM PT: Jim Kerstetter and Ian Lovett of The New York Times writes State of Emergency Declared in California Earthquake
NAPA, Calif. — Gov. Jerry Brown of Caifornia declared a state of emergency for southern Napa on Sunday after a strong earthquake with a preliminary magnitude of 6.0 hit the region, causing scores of injuries and damage and knocking out power to thousands of people across the region.
The governor, in his statement, said his emergency services office would work closely with state and local emergency managers to respond to residents and critical infrastructure that were affected.
The temblor struck about 10 miles northwest of American Canyon — six miles south of Napa — around 3:20 a.m., according to the United States Geological Survey. It was the most powerful earthquake to hit the Bay Area since the Loma Prieta earthquake of 1989, which collapsed the Bay Bridge. At least four aftershocks were reported Sunday.
“A quake of that size in a populated area is, of course, widely felt throughout that region,” Randy Baldwin, a geophysicist with the United States Geological Survey in Golden, Colo., told The Associated Press. “The 6.0 is a sizable quake for this area. It’s a shallow quake. It’s about 6 miles deep. We received hundreds of reports on our website from people that felt it in the surrounding area.”
A CNN reporter says geolists say a 6.0 of such shallow depth can be felt as it were a 7.0 earthquack at a deeper depth.
11:10 AM PT:
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11:11 AM PT
11:27 AM PT: U.S. Geological Survey Official Earthquake Event Site
Event Time
2014-08-24 10:20:44 UTC
2014-08-24 03:20:44 UTC-07:00 at epicenter
2014-08-24 06:20:44 UTC-04:00 system time
Location
38.215°N 122.318°W depth=10.7km (6.6mi)
Nearby Cities
6km (4mi) NW of American Canyon, California
9km (6mi) SSW of Napa, California
13km (8mi) NNW of Vallejo, California
14km (9mi) SE of Sonoma, California
82km (51mi) WSW of Sacramento, California
Related Links
Aftershock Warning
Additional earthquake information for California
Additional earthquake information for United States
Tectonic Summary
The earthquake lies within a 70-km-wide (44 miles) set of major faults of the San Andreas Fault system that forms the boundary between the Pacific and North American tectonic plates. The persistent northwestward movement of the Pacific plate relative to North America primarily causes right-lateral slip across the major faults, but also causes deformation between the major faults. The ongoing complex deformation field is revealed by modern geodetic surveys and earthquake patterns as well as the regional geologic structure. The earthquake is located at the eastern shore of San Pablo Bay between two major active fault systems: the Hayward-Rodgers Creek Fault system on the west and the Concord-Green Valley Fault system on the east. The earthquake occurred near the well-known West Napa Fault, and the less well known Carneros-Franklin Faults, which juxtapose different suites of rocks. Although there are several faults in the region of the earthquake, only the West Napa Fault is known to have displaced Holocene-age sediment — which is positive evidence of surface fault rupture in the last 11,000 years.
Historically, in this region shaking sufficient to seriously damage structures at Mare Island occurred during the M6.8 1868 Hayward Fault earthquake, the M7.8 1906 San Andreas Fault earthquake, and particularly during the M6.3 1898 Mare Island earthquake. The 1898 earthquake may have occurred about 20 km (12 miles) to the northwest on the southern Rodgers Creek Fault. Even larger nearby events than the 1898 earthquake can be expected in the future. In addition, the epicentral region of this earthquake is depicted on the USGS National Seismic Hazard Maps to have a high probability of strong shaking in the future.
The earthquake is located between two major, largely strike-slip fault systems. The Hayward-Rodgers Creek Fault system, which is approximately 7 km (4 miles) west of the site, generated damaging earthquakes in 1868 and probably in 1898. The Concord-Green Valley Fault system, which is 12 km (7 miles) east of the site, produced a M5.5 earthquake in 1954; while it has not generated a large historical event, there is strong evidence for recent pre-historic activity. The 1999 Working Group on California Earthquake Probabilities (WG99, 1999) concluded that the Hayward-Rodgers Creek Fault system has a 32 percent probability of generating a large earthquake (M6.7 to 7.4) by the year 2030, and the Concord-Green Valley Fault system has a 6 percent chance of generating a large earthquake (M≥6.7) in the same time period.