The relative motion on this fault is not well known but thought to be about 1 mm/yr (0.04 in/yr). The 2014 Mw 6.0 South Napa earthquake occurred on the West Napa Fault Zone (WNFZ) and caused damage in and around the City of Napa. Helley and Herd (1977 #509) first named the northwest to north northwest-striking zone of predominantly dextral slip faults the West Napa fault zone. A new order from President Trump is racist, says the head of a local agency that intends to defy it The epicenter of the 2000 M L 5.2 Yountville earthquake occurred 5 km west of the surface trace of the West Napa Fault as defined by Helley and Herd (1977), and thus the source of the earthquake was assigned to an unmapped fault. We separately acquired P- and S-wave data at every station using multiple hammer hits, which were edited and stacked into individual shot gathers in the lab. West Napa fault, Browns Valley section (Class A) No. Mapping the exact location of the aftershocks in three dimensions will yield a picture of the actual fault plane underground. The fault zone that ruptured in the South Napa earthquake had been previously recognized as a strand of the West Napa Fault zone . Some significant faults in the region are the Calaveras, Concord-Green Valley, Greenville, Hayward, Mt. 60 miles taking this route:Take I-80 WEST, from Sacramento, to SR-12 to NAPA at EXIT 39B.Take SR-12 WEST to Today's earthquake was between a pair of active fault systems, the Hayward-Rodgers Creek Fault system and the Concord-Green Valley Fault system. Parts of the West Napa Fault Zone ruptured during the Aug. 24, 2014 South Napa earthquake, they said. It has been mapped as a Late Pleistocene-Holocene active fault, and is considered to be predominantly a right lateral strike-slip fault. This was a shallow-focus … The most common usage in recent literature is West Napa fault. The West Napa Fault runs between the valleys on the eastern edge of the mountains. The West Napa Fault is part of the huge fault zone extending outward from the San Andreas Fault, which lies about 31 miles (50 km) west of Napa Valley.The San … The whole zone is about 70 km (44 mi) wide. (hra093) This early work reported that the fault and its branches extend 30-35 km along the western margin of the Valley; the Wesling and Hanson report suggests that the fault is 57 km long, extending from Carquinez Strait … Most Popular on TIME… a strike slip fault. The West Napa Fault has identified to have the potential capacity to generate a 6.8 to 7.1 magnitude earthquake (Napa County, BDR, 2005). Our seismic survey was designed to image a strand of the West Napa Fault Zone (WNFZ), which ruptured during the 24 August 2014 Mw 6.0 South Napa Earthquake. As noted in Table 4.10-3, there are four faults (West Napa, Hunting Creek, Green Valley and Cordelia) that are of concern to Napa County. Napa Valley quake . The M=6.0 earthquake injured 120 people, three critically, and caused localized damage in Napa Valley. The West Napa Fault and its branches were first mapped by Weaver (1949), and subsequent work extended from the 1970's into the 1990's (references in the article cited). However, the fault had not been identified as being particularly hazardous prior to the quake that hit on 24 August. In October 2016, we acquired high-resolution P- and S-wave seismic data along a 120-m-long, SW-NE-trending profile in Napa, California. The West Napa fault extends along the western margin of the basin that underlies much of Napa Valley. 36a Last Review Date: 2000-06-07 ... Bryant, W.A., 1982, West Napa fault zone and Soda Creek (East Napa) fault, Napa County: California Division of Mines and Geology Fault Evaluation Report FER-129, microfiche copy in Division of Mines and Geology Open-File Report 90-10, 18 p., scale 1:24,000. We acquired seismic reflection, refraction, and guided-wave data along a 115-m-long profile across the known surface rupture zone of the West Napa Fault zone. The San Andreas Fault System is an active plate boundary comprising right-lateral strike-slip faults that runs nearly the length of California. by Dr. Wendy Bohon. Napa lies exactly in the axis - or "along the strike" as seismologists call it - of the West Napa Fault, the assumed origin of Sunday's quake. This earthquake nucleated ~11km beneath Napa Valley on or near the West Napa fault, which is itself one a series of subparallel right-lateral strike-slip faults that comprise the San Andreas fault system. But there is also another factor during the earthquake which can determine the zones of damage, that is the direction of the rupture itself. The West Napa fault was more completely mapped by Fox and others (1973 #5253). 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