Later investigations confirmed the shaking recorded on seismic instruments was consistent with the observed damage in the downtown area of Napa. Key Recovery Factors for the August 24, 2014, South Napa Earthquake Aftershocks during the first week after the mainshock. Copy Link. The shaking causes the shifting of below-surface features that may temporarily (and sometimes permanently) change the flow from a spring or even stop the flow. (Credit: Tim Dawson, California Geological Survey. “Did You Feel It?” community intensity map indicating the severity of shaking felt by people in central California during the South Napa Earthquake in 2014. This kind of hydrogeologic response to earthquakes is well known to scientists. The South Napa earthquake was very well recorded and produced a number of strong ground motion recordings that are of considerable interest to the engineering community. The length of the rupture was about 12.5 km (8 mi), and scientists measured up to 46 cm (18 in) of slip. A strong, 6.0-magnitude earthquake jolted Northern California yesterday (Aug. 24) at 3:20 a.m. local time. On August 24, 2014, a magnitude-6.0 earthquake occurred in Napa, California. A. Show more about Online Teaching suggestions Webinar about teaching this module: Addressing Earthquake Hazards with LiDAR, GPS, and InSAR in Upper-level Undergraduate Courses 2014 South Napa Earthquake – 3D Print Two weeks ago on the night of August 24, 2014 I was shaken awake by the 6.0 magnitude earthquake that struck Napa, CA. USGS PAGER Assessment for the 2014 South Napa Earthquake with initial estimates of fatalities and economic loss. Geologic Hazards Science Center, Golden, Colorado. In response to this earthquake, the Special Projects task of the National Earthquake Technical Assistance Program (NETAP) under FEMA Contract HSFE60-12-D-024 with the Applied Technology Council (ATC) These measurements are probably minimums for the zone since the deformation was probably distributed over an area of several meters wide. It caused much damage and injured many. USGS Geologists inspecting fault trace in a trench dug across one of the ruptures from the 2014 South Napa earthquake. Shallow slipping across the fault, known as afterslip, continued after the mainshock and lasted for several months. (Public domain.). The only other noteworthy earthquake in the Napa area in the recent past (since 1973) was the M4.9 Yountville earthquake on September 3, 2000. The highest intensities were MMI VII-VIII in the city of Napa and extending a littler farther north. Inspection of the buildings after the earthquake yielded 100+ red-tagged structures, meaning immediate rehabitation is too dangerous. They walked across the landscape to trace where the fault had ruptured the Earth’s surface, and mapped the earthquake surface rupture and post-earthquake afterslip, in great detail using mobile laser scanning (a truck-mounted Lidar system), alignment arrays (such as creepmeters that directly measure extremely small fault movements), GPS measurements, and satellite-based radar surveys (InSAR and UAVSAR). Once fully implemented in the western U.S., the advance warnings of a few seconds up to a minute or more provided by the ShakeAlert system can be enough to slow public transit systems, open fire-house doors, and allow people to “Drop, Cover and Hold On.” Although there were no trains running at 3:20 a.m. when the earthquake happened, the Bay Area Rapid Transit (BART) system’s automated train-stopping system did successfully activate when the warning was received. An earthquake measuring an estimated 6.0 struck southern Napa County at 3:20 a.m. on Aug. 24, 2014 with widespread reports of damage throughout … Our better scientific understanding of the 2014 earthquake sheds light on the nature of earthquake faults and hazards in the region, and will enable communities to be better prepared and better able to withstand the next earthquake. Following the event, geologists made more than 1,200 field observations at locations where tectonic faulting and ground failure produced visible deformation that fractured and disturbed the ground surface. There was one fatality due to the earthquake, and at least $500 million in economic losses. Numerous vehicles were trapped by fallen carports at the Charter Oaks apartments on Browns Valley Road in Napa, Calif., following the South Napa earthquake Sunday morning, Aug. 24, 2014. ), Napa Valley area red- and yellow-tagged structures shown as red and yellow squares. Damage to structures decreased with distance from the rupture. The relative motion on this fault is not well known but thought to be about 1 mm/yr (0.04 in/yr). Predictions included broad spectrum events for 8/25/14 at 1413 UTC. the sedimentary basin - soft sediments amplify the shaking. Assuming a continuous fault zone, the West Napa – Franklin Fault zone could be capable of generating a much larger magnitude earthquake than the M 6.0 that occurred on August 24, 2014. The California Geological Survey (CGS) is currently remapping the West Napa Fault System in concert with fault excavation (trenching) studies carried out by the USGS and CGS to evaluate the prehistoric record of rupture on the various fault strands. Cullen 328 Let's discuss it 05:47, 26 August 2014 (UTC) This article in the San Jose Mercury News, published about 80 miles away, specifically mentions that "South Napa Earthquake" is emerging as the accepted name. Public domain. Ongoing fault movement along the surface rupture, called afterslip, continued for several months, and caused further damage to foundations and structures. For example, the California Department of Transportation (Caltrans) received an automated report that they could use to determine which bridges and overpasses experienced the greatest level of shaking and were most at risk to damage so they could prioritize inspections. ShakeMaps provide near-real-time maps of ground motion and shaking intensity following significant earthquakes. Hurricane Marie peaked on 8/24 at 21 UTC - about 2 hours from the Peru earthquake. Afterslip rates decreased dramatically in the months following the earthquake and is still being monitored by the USGS. Scientists found that some of the fault segments that ruptured on the morning of August 24 had been previously mapped as part of the West Napa fault system, but the rupture also extended northward where no faults had been mapped before. Key Recovery Factors for the August 24, 2014, South Napa Earthquake. The South Napa earthquake occurred on Sunday, 24 August 2014 at 3.20 am local time at a depth of 10.7 km, having MW 6.0 and causing significant damage to unreinforced masonry (URM) buildings Aug 25, 2014. The 6.0-magnitude quake struck at 3:20 … Results suggest the West Napa Fault and the Franklin Fault (to the southeast) may be continuous at depth. Open-File Report 2014–1249 >> Pubs Warehouse > OF 2014–1249. ShakeCast is an application for automating ShakeMap delivery to critical users and for facilitating notification of shaking levels at user-selected facilities. Pavement buckling and tented sidewalk resulting from compressional forces at north end of main fault rupture, Sandybrook Lane, Napa California. (Josh Edelson/AFP/Getty Images) the commercial buildings were pre-1950 masonry and had not been built to current code standards or retrofit. It was the largest earthquake to hit the Bay Area since the 1989 World Series quake. Or, try our Real-time Notifications, Feeds, and Web Services . It provides an excellent example for studying crustal strain associated with the earthquake cycle of a strike-slip fault with clear societal relevance. But this was no small earthquake, and as the small representative sample of Jawbone© data shows, many residents had trouble going back to sleep after this one. The crosses and letters indicated cross-sections not shown in this image. LOS ANGELES _ In a land where the mildest rumble elicits an anxious question _ "Did you feel that?" This event was of great interest to seismologists, especially at the Berkeley Seismolgical Laboratory. Many others spread out across the Napa Valley and surrounding area to collect additional data such as fault rupture expressed on the ground surface, as well as shaking induced damage to buildings and infrastructure. The city of Napa was very strongly shaken: many historical masonry buildings and older residences were damaged. After the 2014 South Napa Earthquake, approximately half the households in the city of Napa and in western Vallejo that reported an injury stated that the injury occurred dur-ing cleanup activities. Almost three years have passed since the 2014 magnitude-6.0 South Napa earthquake. The West Napa fault extends along the western margin of the basin that underlies much of Napa Valley. The August 24, 2014, South Napa earthquake (M6.0) produced significant damage resulting from shaking, fault rupture, fault afterslip, and ground deformation. maps compiled from these personal accounts, reflected peak shaking intensities up to a “severe” level, just a little bit less than the “violent” shaking calculated in the instrument-generated ShakeMaps. The 2014 South Napa earthquake was the first large earthquake (Mag 6) to occur within the Plate Boundary Observatory GPS network since installation. The number of aftershocks was less than usual for an earthquake of this size, 80 during the first month following the mainshock, compared to 320 following the M6.0 in Parkfield in 2006. (Public domain. To determine the continuity and extent of the faults that ruptured during the South Napa earthquake and its aftershocks, and to search for possible interconnections with other mapped faults, USGS recorded aftershocks using temporary seismograph arrays that were positioned across the rupture zone and mapped faults located north and south of the rupture. Hydrograph showing stream flow in cubic feet per second on USGS streamgage on Sonoma Creek near Agua Caliente, from about August 23 – September 13, 2014. The earthquake's epicenter was a few miles south of Napa … Office of Communications and Publishing12201 Sunrise Valley DriveReston, VA 20192United StatesPhone: 703-648-4460. The epicenter of that earthquake was 20 km (12 mi) NNW of the South Napa epicenter, and also on the West Napa fault system. The sharp rise starting on August 24 reflects an increased streamflow due to the South Napa Earthquake. The team comprised a diverse mix of perspectives and backgrounds, including The magnitude 6.0 earthquake occurred early in the morning on August 24, 2014, on the West Napa Fault. These activities resulted in a comprehensive understanding of fault motion and ground response, in ways that could not have been imagined the last time (1989) there was a large quake in the San Francisco Bay Area. 1: What does it mean if my apartment building was red, yellow, or green tagged*? There was no evidence for the shaking being strongly amplified in any particular pockets of the downtown area. A few homes even shifted off of their foundations, which can be due to the failure of the cripple walls, which drop the floor to the foundation and sometimes allow houses to slide off the foundation. This earthquake was unusual for its size, because it had a relatively long surface rupture of 12.5 km (8 mi) with a significant amount of surface slip (up to 46 cm; or 18 in). When the pressure adjusts and equilibrates with the water table, the flow will often return. Engineers and scientists determined that the worst-damaged buildings resulted from a combination of: The South Napa earthquake caused this ground surface rupture running through a viineyard near Buhman Road, Napa Valley, California. The red star is the location of the mainshock. The numbers of aftershocks following the earthquake was relatively low for an earthquake of this size, and in contrast to other large Californian earthquakes, the aftershock locations do not clearly outline the main fault rupture surface. In the case of re trospective full-waveform inversions, a network with station spacing of 10km within the epicentral distanc e of 30km is able to provide adequate stable key source parameters if the preestimated hypocenter and fault ori entation are accurate of ±5km and ±15°, respectively. USGS geologists and geophysicists, along with their colleagues from federal, state, and local government agencies and academia, started conducting field work immediately after the earthquake. First, to put the South Napa earthquake in context, the West Napa fault, which was the causative fault, is part of the large San Andreas Fault Zone (SAFZ) system. Recent advances in technology let to more rapid assessment of the nature and effects of this quake, showcasing significant advances since the previous big quake in the San Francisco Bay area in 1989 – the magnitude 6.9 Loma Prieta earthquake. The California Integrated Seismic Network detected the South Napa earthquake immediately, and the first ShakeMap, issued four minutes after the earthquake, depicted the violent shaking in the immediate area. Ground shaking was significant with accompanying maximum Modified Mercalli Intensities between VIII and IX. Over 41,000 people went online to report what they felt during the event. Facebook. (Josh Edelson/AFP/Getty Images) Kids skateboard over buckled roads in a residential neighborhood of Napa. We can use this increased knowledge to make our communities safer and more resilient in future quakes. August 25, 2014 at 8:22 PM The WNFZ was mapped as a 46-kilometer long segment of subparallel fault traces from Vallejo to Saint Helena, California. Afterslip causes additional damage to manmade structures, such as roads, but does not release seismic waves and cause shaking. The epicenter of that earthquake was 20 km (12 mi) NNW of the South Napa epicenter, and also on the West Napa fault system. Residential structures and wineries surrounding this area were significantly damaged. (Public domain.). The earthquake fault rupture extended northward from the epicenter, directing much of the seismic energy toward the city of Napa. Copy Link. In the days, weeks and months that followed, scientists collected and analyzed data from instruments that recorded the event. ), Locations of the traces of tectonic surface faulting produced by the South Napa earthquake overlain on an aerial photograph. The same could be said for the tornados in the midwest and south, and hurricanes in the southeast coastal areas. Frequently Asked Questions (FAQs) for Tenants After the 2014 South Napa Earthquake To aid tenants who have been affected by the 2014 South Napa Earthquake. The prototype earthquake early warning “ShakeAlert” system provided about 5 seconds of warning to test users 23 miles away in Berkeley and a 9-second warning to San Francisco, 31 miles away. The South Napa Earthquake caused extensive damage through both ground shaking and surface cracking (rupture). the wood-frame houses that were damaged were older ones that had not been retrofit (see links below for retrofitting information). With one fatality, and approximately a half billion dollars of economic damage, the city of Napa is still recovering from last year’s quake. The earthquake woke people throughout northern California, in cities as far away as Sacramento and Santa Cruz. Symbol size represents earthquake magnitude, and fill color represents depth. Caption: A map shows the location of the August 24, 2014 earthquake just south of Napa, California. The "Did You Feel It?" These maps are used by federal, state, and local organizations, both public and private, for post-earthquake response and recovery, public and scientific information, as well as for preparedness exercises and disaster planning. In response to the earthquake, California Earthquake Clearinghouse established a physical clearinghouse location in Napa, CA from August, 24 to August 26, 2014. Both the Napa and Peru earthquakes struck within about one day of this prediction. Data collected from airborne LIDAR were used to look for effects on the ground surface. The magnitude 6.0 earthquake occurred early in the morning on August 24, 2014, on the West Napa Fault. Geographic Names Information System (GNIS), Mapping, Remote Sensing, and Geospatial Data. The discharge of springs and groundwater to these streams began within an hour after the earthquake, increasing intermittently from 0.1 to nearly 3 cubic feet per second within a couple of weeks. California Governor Jerry Brown called it the "South Napa Earthquake" in his official emergency declaration, widely reported in the press. In a new report, scientists from MIT and elsewhere detail how, even after the earthquake’s main tremors and aftershocks died down, earth beneath the surface was still actively shifting and creeping — albeit much more slowly — for at least four weeks after the main event. The 24 August 2014 Mw 6.0 South Napa earthquake occurred on … Warmer colors represent stronger shaking. There is no denying that. USGS issued a forecast for the continuing afterslip for some homes that was included in the report for FEMA. map with 41,356 responses as of this writing. Mapped faults and seismicity (magnitude 3+, 1947-2007) prior to the August 24, 2014 South Napa earthquake. Skip Links. performance of buildings after earthquakes. The South Napa Earthquake provided a valuable reminder to engineers and the public of what they should expect from time to time when they live in earthquake country. Nicholas George looks under a buckled highway just outside Napa. Overview. With each earthquake experienced, scientists learn more about the hazards, and how the natural and built environment will respond. No other surface features were found, such as evidence of liquefaction or landslides. Following the South Napa Earthquake on August 24, 2014, the Earthquake Engineering Research Institute (EERI) convened a small team of researchers to develop an approach for studying the resilience of businesses impacted by major earthquakes. The Did You Feel It? The South Napa earthquake included a few small segments that ruptured together to produce the M6 earthquake.. One year ago, the largest earthquake in over 25 years hit the San Francisco Bay Area, causing significant damage in California’s famous Napa Valley. A smaller magnitude 5.0 earthquake on the same fault had damaged the city of Napa in 2000. The computed instrumental intensities agreed well with those reported by residents. Previous smaller earthquakes in the area also triggered relatively few aftershocks for their size, suggesting that this area doesn’t produce many aftershocks. The M6.0 South Napa earthquake occurred on August 24, 2014. In the wee hours of Sunday morning at 3:20am, the residents and wineries of Napa Valley were shaken by a magnitude 6.0 earthquake, the largest in the San Francisco Bay Area in over 25 years, and the first since the M7.9 1906 earthquake to rupture on the surface. (see directivity). Olivia Allen-Price. An Instrumental Intensity “ShakeMap,” depicts the ground shaking produced by the 2014 South Napa earthquake. M 6.0 - South Napa Within 1 hour after the earthquake, over 25,000 citizen scientists entered their data on the website, creating a map of the distribution of shaking that they felt. The Earthquake Event Page application supports most recent browsers, view supported browsers. Damage to wood-frame houses was mostly broken or cracked chimneys and failure of cripple walls (see Additional Resources below), short walls in the crawl space between the foundation and the floor. After the earthquake, one or more types of traumatic exposure were reported among 27% and 4% of Napa and western Vallejo households, respectively; _ having even a few seconds of warning before an earthquake Hydrograph showing stream flow in cubic feet per second on USGS streamgage on Sonoma Creek near Agua Caliente, from about August 23 - September 13, 2014. One year ago, the largest earthquake in over 25 years hit the San Francisco Bay Area, causing significant damage in California’s famous Napa Valley. Afterslip is a slow movement on the fault, and it is yet unclear whether it is associated with, or independent of, the aftershocks. The Mw 6.0 South Napa earthquake of August 24, 2014, produced complex and extensive surface faulting and other ground deformation features. Global predictions for localized events were posted on Astrosymm.com on 6/14/14. Afterslip forecast hazard map of the Browns Valley neighborhood and surrounding area in Napa, Calif. After the 2014 South Napa Earthquake, approximately half the households in the city of Napa and in western Vallejo that reported an injury stated that the injury occurred during cleanup activities. (Public domain.). This detailed assessment of the South Napa earthquake and the West Napa Fault system helps scientists assess future earthquake hazards in the area so communities can better prepare for them. Where I was in San Francisco wasn’t close enough to the epicenter to do much other than wake people up. Sometimes a single fault segment will slip and cause an earthquake, and other times many fault segments slip in unison, causing a larger earthquake. 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