EERI Special Earthquake Report – October 2014

EERI Special Earthquake Report M 6.0 South Napa Earthquake of August 24, 2014

This report describes the findings led the development of this summary California. The cities of Napa, of members of the Earthquake report as well as the EERI briefing American Canyon, and Vallejo are Engineering Research Institute (hosted jointly with PEER). The fol- located in the area of strongest (EERI) and their colleagues who lowing members served as Disciplin- ground shaking, and had the most conducted reconnaissance through ary Leads to coordinate the compila- damage. Figure 1 shows the epi- the California Earthquake Clearing- tion of observations in their topic area central area of the earthquake, with house. The California Earthquake for both the briefing and this report: MMI shaking intensities overlaid on Clearinghouse is managed by Ibrahim Almufti, Andre Barbosa, population density. The total popu- the California Geological Survey Jonathan Bray, Timothy Dawson, lation within MMI VI is estimated (CGS), EERI, the United States Joshua Marrow, Mike Mieler, Charles to have been about 200,000, with Geological Survey (USGS), the Scawthorn, and Mark Yashinsky. approximately 36,000 subjected California Office of Emergency Each of the leads worked together to shaking at the level of MMI VIII Services (CalOES), and the Cali- with numerous other reconnaissance (Table 1). fornia Seismic Safety Commission volunteers to incorporate a broad (CSSC). Many other organizations spectrum of observations. Though ≥ MMI Population participated in reconnaissance this report intends to be comprehen- VI 199,000 activities including, Geotechnical sive, it is not exhaustive. Extreme Events Reconnaissance VII 90,000 (GEER) Association; Pacific Earth- EERI’s coordinating role as a part of VIII 36,000 quake Engineering Research the California Earthquake Clearing- Center (PEER); California Depart- house was made possible by funding Table 1. Estimated population with ment of Transportation (Caltrans); from FEMA. This report is published MMI isoseismals (source: Charles the American Society of Civil Engi- as part of EERI’s Learning from Scawthorn, published sources). neers’ Technical Council on Lifeline Earthquakes Program. Earthquake Engineering (TCLEE); One fatality and approximately 200 and the Structural Engineers Asso- Introduction injuries were attributed to the earth- ciation of California’s Post-Disaster quake; many more minor injuries Performance Observation Com- The Mw 6.0 South Napa earthquake were caused by cleanup activities. mittee. The EERI Reconnaissance struck at 3:20 am (PDT) on August The number of severe injuries and Leader, Marko Schotanus, coordi- 24, 2014, just north of San Francisco, fatalities would have been much nated reconnaissance efforts and higher had the earthquake struck during the day. Fallen debris from collapsed walls and façades, and Figure 1. toppled heavy building content did Epicentral pose life safety risks. area of South Napa earth- Much of the fault rupture extended quake, show- to the ground surface, and it ing location of crossed through the western neigh- fault rupture borhoods of Napa, causing damage and after- to streets, sidewalks and houses. shocks, and The event also caused strong MMI intensities ground shaking, in some locations overlaid on exceeding design ground motions. population den- sity (source: There was significant damage to Charles Scaw- lifelines and structures, and dis- thorn, SPA ruption to businesses. Damage to Risk). lifelines consisted mainly of pipe breaks, and there was generally

1 EERI Special Earthquake Report – October 2014

scientific and engineering commu- Figure 2. nities with agencies and organiza- Clearing- tions responsible for emergency house Field- response and recovery so that their notes Tool findings can inform the response map inter- and recovery efforts. During its face and three days of operation, over 100 data experts visited the clearinghouse colletion location and participated in recon- screen naissance activities. Their expertise (source: spanned many disciplines: geosci- EERI). ences, geotechnical engineering, structural engineering, nonstructural components, insurance, lifelines, transportation, government, risk analysis, and business continuity. They represented over 40 organiza- only limited loss of service. Severe earthquake, the California Earth- tions. structural damage was mostly quake Clearinghouse was activated limited to older wood-frame houses and a physical clearinghouse loca- This was the first California earth- and unreinforced masonry buildings tion was operational by 3:00 pm quake with a magnitude and with known vulnerabilities. Non- on August 24. The CGS serves as damage sufficient to trigger the structural damage was more wide- the lead organization and provides establishment of a clearinghouse spread, and included a few large all coordination for state resources since the 1994 Northridge earth- engineered buildings of the last required for clearinghouse activation. quake. However, in the intervening decade in downtown Napa. Non- The clearinghouse was located at the years, regular exercises and activi- structural damage was the primary Caltrans Maintenance Facility on Jef- ties of the California Earthquake cause of business interruption. ferson Street in Napa, with a Caltrans Clearinghouse managing partners mobile satellite communications truck allowed for the establishment of In the following sections, the providing phone and internet connec- a timely, relevant response that authors who contributed to each tivity. The physical clearinghouse was utilized modern approaches to data section are listed at the start of operational from Sunday August 24 collection, visualization and shar- each disciplinary topic area. Com- through Tuesday August 26. ing. This is the first earthquake in plete acknowledgements for each California where data were col- section are summarized at the end The purpose of the California Earth- lected and displayed in near-real of the document. quake Clearinghouse is twofold: (1) it time through the clearinghouse, allows all agencies in the field to coor- and where many layers of data, Clearinghouse Operations dinate reconnaissance efforts, admin- collected by different individuals (Heidi Tremayne, EERI; Maggie Ortiz, ister access to restricted areas, share and organizations, were all acces- EERI; Alex Julius, EERI; Marjorie findings, and make plans for teams in sible through one data viewer. Greene, EERI; Anne Rosinski, Califor- the field each day; and (2) it links the Essentially a breakthrough in terms nia Geological Survey; Luke Blair, U.S. Geological Survey; Fred Turner, Califor- nia Seismic Safety Commission) Figure 3. Clear- inghouse After a major earthquake in Cali- online multi- fornia, the California Geological disciplinary Survey (CGS) is mandated to data map, establish a clearinghouse, along managed with its managing partners, EERI, by EERI, as the United States Geological captured on Survey (USGS), the California September Office of Emergency Services 6, 2014 (CalOES), and the California Seis- (source: mic Safety Commission (CSSC). EERI). Within four hours of the South Napa

2 EERI Special Earthquake Report – October 2014 of managing field observations, the 3. EERI Batch Photo Upload Tool • The clearinghouse helped the gains made during the Napa event for geotagged photos is ideal for earthquake community make will inform scientific and engineer- post-processing and annotating notable progress towards ing data collection and analysis in large numbers of photos from a coordinated, longitudinal future events. desktop upon return from the field. data archiving of earthquake This is a .jar application that can damage observations by A key element to the response quickly add annotation and meta- encouraging data sharing was the establishment of a virtual data to photos including photog- and collaboration among the clearinghouse website at http:// rapher name, type of observation, scientific/engineering com- www.eqclearinghouse.org/2014-08- date of acquisition, and caption munities, avoiding duplication 24-south-napa/ to record scientific text. of field efforts, and providing and engineering observations, the data collection and visu- photos and data from the earth- Data from these tools and other alization tools that facilitate quake (Clearinghouse, 2014). This geo-located data submitted by many sharing. website hosted notifications about experts, was visualized via an online reconnaissance efforts, instructions multidisciplinary data map (http:// • With support of the California and links to data collection and bit.ly/1smi6so), shown in Figure 3. Highway Patrol, multiple over- visualization tools, links to media Each of the tools described allows flights were flown with clear- reports, and preliminary reports by upload of image and pdf files, and inghouse experts onboard scientific/engineering experts as live updates to the visualization map. to acquire high-resolution they became available. Otherwise experts could also submit aerial imagery on Sunday and KMZ or KML data layers that were Monday. EERI members and expert visitors uploaded to the visualization map by were encouraged to use a suite EERI staff. The backend database • The Clearinghouse Chair, of data collection tools, developed that hosts these data, along with the Anne Rosinski, coordi- in support of the California Earth- visualization map and virtual clear- nated a coalition of USGS, quake Clearinghouse: inghouse website, will serve as an CGS, Department of Water ongoing and longterm repository and Resources (DWR), Pacific 1. Clearinghouse Fieldnotes archive for scientific and engineering Earthquake Engineering Tool for geo-tagged photos is observations and reports from the Research Center (PEER), and a web-app developed by Scott earthquake. Geotechnical Extreme Events Haefner and Luke Blair of USGS Reconnaissance (GEER) to for field data collection and The California Earthquake Clearing- acquire LiDAR high-accuracy photo documentation using a house for the South Napa earthquake imagery in the most critical web-enabled phone (Figure 2). had several important accomplish- areas. This tool has an easy-to-use ments: interface that allows users to Many lessons from this California enter a field observation using • Field team coordination was Earthquake Clearinghouse activa- one of several simple forms and supported by EERI staff who tion will influence and enhance the attach a relevant photo (Haefner operated from the clearinghouse response to future earthquakes. and Blair, 2014). See http://bay- location to link disparate volun- Notably, improved communica- quakealliance.org/fieldnotes/ teers and experts conducting tions, training, and advanced reconnaissance in the field. coordination are needed to 2. EERI Photo Upload Tool for encourage additional organiza- non-geotagged photos is ideal • Nightly briefings were held at tions and experts to participate for post-processing photos from the clearinghouse location and more fully in reconnaissance a desktop upon return from webcast so that reconnaissance activities. Further improvements the field. This tool has an easy teams and volunteers could are needed in the robustness of point-and-click map interface share synthesized daily findings the data collection tools and the that allows users to upload with the research community, functionality of visualization tools. photos, observations, and the State Emergency Operations The California Earthquake Clear- reports at any clicked upon map Center, the Regional Emergency inghouse managing partners are location or typed-in address. Operations Center, and FEMA preparing an After-Action Report See http://www.eqclearing- Region 9. that will more completely outline house.org/map/? eventid=29 lessons and recommendations for future activations.

3 EERI Special Earthquake Report – October 2014

The following sections of this EERI region that accommodates approxi- the fault in the Napa area (Wesling Special Earthquake Report reflect mately 40 mm/yr of dextral shear and Hanson, 2008; Clahan et al., the collaborative reconnaissance (Figure 4). The fault has been the 2010). Geomorphic expression has observations, findings, and out- subject of several studies that have been used to estimate a slip rate comes facilitated by the California examined evidence for recency of of ~1 mm/yr, and geodetic models Earthquake Clearinghouse. activity (Bryant, 1982; Wesling and estimate slip rates ranging from 1 Hanson, 2008; Clahan et al., 2010; mm/yr to as much as 4.5 mm/yr Geosciences Rubin and Dawson, in progress). (Field et al., 2013). The recurrence (Timothy Dawson, California Geological The fault zone displays evidence of and timing of past surface rupturing Survey; Keith Kelson, U.S. Army Corps Holocene activity in the American earthquakes is unresolved due to of Engineers; Ken Hudnut, U.S. Geo- Canyon area (Bryant, 1982; Wesling an absence of quality paleoseismic logical Survey; Dan Ponti, U.S. Geo- and Hanson, 2008), and reported sites. logical Survey; John Wesling, State of Holocene activity along portions of California Office of Mine Reclamation; CISN ShakeMap : 6.3 km (3.9 mi) NW of American Canyon, CA Bill Barnhart, U.S. Geological Survey) Aug 24, 2014 03:20:44 AM PDT M 6.0 N38.22 W122.31 Depth: 11.2km ID:72282711 Figure 5. 39˚ Tectonic Setting. The earthquake ShakeMap

ruptured the ground surface along Cloverdale showing several strands of the West Napa Roseville instrumental fault zone, a 43-km-long zone of intensity data Sacramento discontinuous faulting (Bryant, 38.5˚ recorded by Santa Rosa NFS #3 2000). The West Napa fault is part Vacaville the California of the system of northwest-trending Integrated Seismic Net- faults in the San Francisco Bay Vallejo Lodi work (CISN). 38˚ San Rafael Stockton (source: USGS, 2014b) San Francisco Tracy km 0 50 Fremont 37.5˚

-123˚ -122˚ Map Version 27 Processed 2014-09-19 05:13:08 PM PDT

PERCEIVED SHAKING Not felt Weak Light Moderate Strong Very strong Severe Violent Extreme POTENTIAL DAMAGE none none none Very light Light Moderate Mod./Heavy Heavy Very Heavy PEAK ACC.(%g) <0.10.5 2.46.7 13 24 44 83 >156 PEAK VEL.(cm/s) <0.07 0.41.9 5.8 11 22 43 83 >160 INSTRUMENTAL INTENSITY I II-III IV VVI VII VIII IX X+ Scale based upon Wald, et al.; 1999

Figure 4. Active faults in the San Francisco Bay Area. Red lines are faults with previously observed historical surface ruptures or that are actively creeping, orange lines are faults with Holocene activity; green lines are faults active in the Late Figure 6. Finite fault model from joint inversion of seismological waveform Quaternary, and purple lines are data, geodesy, and InSAR estimated surface displacements. Yellow star is faults active in the Quaternary. Base earthquake hypocenter, dots are relocated aftershocks, black rectangle at map from ESRI, fault traces from surface is location of maximum slip recorded at surface, which is coincident USGS Quaternary Fault and Fold with peak modeled slip at depth. Note that aftershocks are clustered in the Database (source: Timothy Dawson). southern part of the rupture (source: USGS 2014a).

4 EERI Special Earthquake Report – October 2014

Seismology. The earthquake lateral slip on a northwest-trending, location of the 1898 Mare Island was recorded by the relatively steeply west-dipping fault plane, and earthquake is not known precisely, dense network of seismographs an estimated magnitude of Mw 6.0 intensity data suggest it was about in the region, which resolved the (USGS, 2014a). Strong shaking was 10 km southeast of the epicenter hypocenter to be near the Cut- recorded throughout the Napa Valley of the 2014 earthquake (Bakun, tings Wharf area at a depth of region, with a peak instrumental 1999). 11.3 km. The moment tensor intensity of IX recorded at Napa Fire solution is consistent with right- Station Number 3, located at 38.330, Surface Rupture. The earthquake -122.318 (Figure 5). produced more than 14 km of surface rupture from the Napa River Fault slip models derived from at Cuttings Wharf in the south, to seismological waveform data or joint beyond the northern boundary of inversions of waveform, geodetic, and Alston Park in the city of Napa, in satellite interferometry data indicate the north (Figure 7). The surface that the rupture propagated up-dip rupture is largely west of most and northwest from the hypocenter. mapped traces of the West Napa The maximum slip of ~1 m at depth fault zone, although it is coincident was about 8 km north of the hypocen- with the western-most Quaternary ter, and aftershocks occurred pre- trace of the West Napa fault, and dominantly south of, and deeper than, locally with mapped bedrock faults the area of maximum slip (Figure 6). (Clahan et al., 2004). The fault was previously unrecognized where it The earthquake was centered in an was covered by younger sediment, area of historical seismicity associ- particularly near its northern end in ated with the West Napa fault zone. Browns Valley, and at its southern The 2000 M 4.9 Yountville earthquake end near the Napa River. is associated with the West Napa fault zone (Langenheim et al., 2006) Displacements along the surface and had a zone of aftershocks about rupture are predominantly right- 4 km northwest of the 2014 South lateral and the rupture is highly Figure 7. Map showing location of Napa earthquake rupture. The M 6.3 variable in terms of expression at observed and inferred South Napa 1898 Mare Island earthquake caused the surface. However, rupture is Earthquake fault rupture. Image extensive damage in the Vallejo typically expressed as a zone of base from Google Earth (source: area, near the southern end of the en echelon left-stepping fractures Dawson et al., 2014). West Napa fault zone. Although the (Figure 8), varying from less than

Figure 9. Sur- face fault rupture through vineyard about 6.7 km NW of epicenter, showing offset vineyard rows in area of maximum measured right- lateral offset of 40-45 cm (source: NSF-GEER; GPS N38.2776 Figure 8. Surface rupture west of Buhman Avenue, W122.32377; showing left-stepping en echelon fractures and mole- 08/25/14: 2:23 tracks. Right-lateral displacement was on the order pm) (photo: Keith of 40 cm, with a small amount (~12 cm) of up-on-the- Kelson, USACE). west vertical displacement. GPS location: 38.2924°, -122.3432° (photo: Dawson et al., 2014).

5 EERI Special Earthquake Report – October 2014

one meter to tens of meters wide. Analysis (ARIA) mission, using the the main shock at some locations Right-lateral offsets are as high as Agenzia Spaziale Italiana’s COSMO- that exhibited as much as 20 cm 40-45 cm measured in the area SkyMed satellite. Rupture at the of right-lateral afterslip 48 hours near the intersection of Buhman airport was verified by geologists in afterward. Avenue and Congress Valley Road the field (Figure 10). Uninhabited (Figure 8). aerial vehicle synthetic aperture radar Opportunities to Advance Knowl- (UAVSAR) imagery flown five days edge. The South Napa quake was At the latitude of Browns Valley after the earthquake proved to be the largest one in the San Fran- Road, the rupture was observed useful in identifying other areas of cisco Bay region since the 1989 along two subparallel, northwest possible faulting, and was especially M 6.9 Loma Prieta earthquake, trending strands approximately useful in identifying linear zones of and several research opportunities 500 m apart (Figure 9), with offset deformation that would likely have arise from this event. Following of 10- 20 cm on the western strand, been missed in the field without the the earthquake, new techniques and about 2- 8 cm on the eastern benefit of the InSAR and UAVSAR such as post-earthquake campaign strand. North of Browns Valley, imagery. and continuous GPS monitoring, these strands appear to merge a mobile LiDAR scanning systems few hundred meters south of Alston Afterslip. Within the first 24 hours, (MLS), and various SAR techniques Park. The northern end of the afterslip was expressed as the con- were deployed in order to record rupture has been verified approxi- tinued development of the rupture on the distribution of surface rupture mately 1.2 km north of Alston Park. the ground and the growth through and the amount of coseismic slip time of observed offsets across roads and afterslip. The amount of total Minor right-lateral offset, likely less and other cultural features. The post-earthquake offset is relatively than a few centimeters, also was USGS was able to establish four large for a M 6 main shock and has observed crossing two taxiways at alignment arrays across the fault in implications for the interpretation the Napa County Airport (Figure order to monitor afterslip. Although of standard empirical relationships 10). This rupture is located on the results are not yet finalized, based on between surface displacement and mapped trace of the Airport Sec- episodic field observations in the 26 earthquake magnitude, because tion of the West Napa fault zone days following the earthquake, after- these relationships are developed as designated by Bryant (2000), slip is continuing at the four stations using total slip (including unknown and the rupture was first identi- located within the primary, 7-km-long amounts of afterslip). Because the fied by X-band InSAR results from epicentral part of the rupture (Lien- cross-fault distribution of slip can be NASA’s Jet Propulsion Labora- kaemper, 2014). Little or no offset documented with a high degree of tory Advanced Rapid Imaging and was observed within a few hours of precision, we have better informa- tion on the patterns and relative Figure 10. COSMO- amounts of slip for mitigating fault SkyMed X-band InSAR rupture to pipelines, levees, and image overlain on Google other infrastructure. Earth Imagery show- ing discontinuity (white Geotechnical Engineering arrow) corresponding to (GEER-PEER: Jonathan Bray, UC minor faulting at the Napa Berkeley; Julien Cohen-Waeber, UC County Airport. Upper Berkeley; Tim Dawson, CGS; Tadahiro right photo shows en Kishida, PEER; Nicholas Sitar, UC echelon cracks on airport Berkeley; Christine Beyzaei, UC Berke- taxiway (source: Ken ley; Les Harder, HDR; Ken Hudnut, Hudnut, USGS). Arrows USGS; Keith Kelson, USACE; Robert denote pre-earthquake Lanzafame, UC Berkeley; Roberto vegetation lineament and Luque, UC Berkeley; Dan Ponti, USGS; low scarp (source: NASA Michelle Shriro, GEI; Nathaniel Wagner, Jet Propulsion Laboratory UC Berkeley; and John Wesling, CA Advanced Rapid Imag- OMR) ing and Analysis (ARIA) mission http://photojour- Earthquake Ground Motions. The nal.jpl.nasa.gov/figures/ earthquake produced strong ground PIA18798_fig1.jpg). motions in the northern San Fran- cisco Bay area (Bray et al., 2014).

6 EERI Special Earthquake Report – October 2014

Figure 11. Fault normal and fault parallel velocity time series recorded in the near fault region (source: Bray et al., 2014).

A total of 214 three-component nisms or site effects (e.g., deep basin and RotD100 (maximum rotated uncorrected digital accelerograms response). direction component) were calcu- were downloaded from the Center lated for each recording station. The for Engineering Strong Motion The 5% damped pseudo-spectral spectral values of these records Data (CESMD) and processed acceleration response spectra of the exceeded the ASCE-10 MCE spec- using PEER standard procedures recorded ground motions at the Napa tra within the range of 1-2 s. Peak (Ancheta et al., 2014). Fire Station No. 3 SMS and Napa spectral values approach or exceed College SMS sites are compared the 2475-year return period UHS Of particular importance were to ASCE 7-10 design spectra and values at these two Napa stations. intense ground motions in the USGS uniform hazard spectra (UHS) heavily damaged areas in and in Figure 12. The square root sum High-frequency spikes were around Napa. Pulse-like waveforms of squares (SRSS) of the two hori- observed in the Carquinez Bridge were observed in several of the zontal components, and the RotD50 Geotechnical Array #1 records, velocity time series at the near-fault (median rotated direction component) which reached approximately 1.0 g stations shown in Figure 11. The maximum recorded peak ground velocity (PGV) was 92 cm/s at the Napa Fire Station No. 3 strong motion station (SMS). Several sta- tions exhibited pulse-like motions in both horizontal components (Napa Fire Station No. 3, Lovall Valley Loop Road, and Napa College). The Main Street and Huichica Creek SMS exhibited velocity pulses in their fault normal and fault parallel components, respectively. The velocity time series of five near-fault records contained veloc- ity pulses with periods within the expected range of 0.7- 2.0 s for soil sites shaken by a M 6 event (Bray et al., 2009), but they also con- tained longer-period pulses signifi- cantly higher than this range. It is not clear if the longer-period pulses were due to fault rupture mecha- Figure 12. Comparison of code spectra and UHS for the Napa Fire Station and Napa Valley College (source: Bray et al., 2014).

7 EERI Special Earthquake Report – October 2014

high-frequency spikes are observed movement displaced another house in the S-wave portion of the wave- structure 6 cm from its foundation. form from a depth below 100 m to the Structures that were tied into the surface. This observation suggests ground, e.g., pier and grade beam that the large PGA observed at Car- foundations, were damaged at a quinez Bridge Geotechnical Array #1 higher rate than ring-wall with sus- is in part a result of site amplification pended timber floor foundations. due to local soil conditions. However, these observations do not exclude A distinct damage mode involved the possibility of soil-structure interac- compressional and extensional tion effects on the measured record- failures within relatively new, stiff ings. concrete sidewalks and curbs off of the primary fault trace throughout The 5% damped pseudo-spectral the Browns Valley area (Figure 15). accelerations from the recorded Newly placed sod with a geotex- ground motions compared well to tile backing was warped in places those estimated with the recent similar to what one might see when NGA-West2 Ground Motion Predic- a rug is shaken from one end. The tion Equations (GMPE; Bozorgnia et sidewalk failures appeared to be a al., 2014). The comparison shows manifestation of localized zones of generally a good agreement for both compression and extension distinct Figure 13. Surface fault rupture horizontal and vertical components from the surface fault rupture, and in Browns Valley area (fault trace near the fault, with the exception of possibly induced by intense tran- mapped by NSF-GEER team mem- the large high-frequency motions sient surface waves. Other potential bers overlain on GoogleEarthTM observed near the Carquinez mechanisms are ground deforma- image; source: Bray et al., 2014). Bridge and the large velocity pulses tions associated with surface fault- observed in the near-fault region, as ing or lurching of compacted earth for the NS component. The spikes discussed above. fills. were investigated by comparing the acceleration time series at sev- Geotechnical Effects. Surface fault- Although the Napa area was eral stations along the path from ing damaged homes, underground strongly shaken by this event, there the epicenter to the sites and the utilities, and other infrastructure was a noticeable lack of liquefaction downhole array records. The spikes where the fault traversed developed and liquefaction-induced ground were observed in the S-wave por- areas, such as the Browns Valley failure, even in areas previously tion of several of the records. This residential area in western Napa identified as being susceptible to suggests that the spikes could be (Figure 13). Right-lateral surface fault the hazard. Dam and levee perfor- a result of path effects. The spikes rupture deformation in this area was mance was generally excellent, and increase in amplitude from the on the order of 10 - 20 cm. The sur- only a few cases of minor cracking Vallejo–Hwy 37/Napa River East face fault rupture damaged the house were observed. Similarly, under- Geotechnical Array to the Carqui- structure shown in the left photograph ground storage caverns at local nez Bridge Geotechnical Array #1. of Figure 14. The right photograph wineries performed well, with only Downhole records show that two shows where the surface fault ground minor cracking reported at some of the installations.

Figure 14. Effects of surface fault rupture on infrastructure in Browns Valley area; left--home severely damaged (NSF-GEER: N 38.3025 W122.3436; 08/25/14), and right- -foundation offset 6 cm (NSF-GEER; N 38.3038 W 122.3430; 08/25/14) (source: Bray et al., 2014).

8 EERI Special Earthquake Report – October 2014

Figure 15. Top--buckled sidewalk (NSF-GEER: N38.3039 W122.3430; 08/25/14); middle--sidewalk cracks (NSF- GEER: N38.3064 W122.3456; 08/28/14); and lower--warped sod (NSF-GEER: N38.3065 W122.3455; 08/28/14) indicating compressional and extensional zones in compacted fill near fault trace in Browns Valley area. (source: Bray et al., 2014).

Opportunities to Advance site effects on ground motion char- or slope movements; hence, further Knowledge. Much can be learned acteristics. Most of the strong motion study is warranted. Sites that were from a comprehensive study of the sites require shear wave velocity mapped as being liquefiable that did ground motions produced by this measurements to characterize the not exhibit liquefaction should be earthquake, including near-fault Vs30 of the sites. The characteristics better characterized and added to velocity-pulse effects, the unusu- of surface fault rupture were well the liquefaction-triggering database. ally intense high-frequency spikes captured, and they offer the opportu- The cause of damage to buried in the acceleration time series at nity to better understand the char- utilities in areas that did not undergo the Carquinez Bridge site, and the acteristics of ground deformations in significant permanent ground effects of the Napa basin and local close proximity to the fault rupture. displacements should be inves- The effect of surface fault rupture on tigated. Lastly, the documented homes and other infrastructure is a performance of dams, levees, other particularly fruitful avenue of further earth structures, and natural slopes study. Structures with different foun- provides the opportunity to evalu- dations can be investigated to better ate commonly employed analytical understand how each foundation procedures. system responds to, and performs in areas of ground deformation from Lifelines surface faulting. The alternating pat- (ASCE TCLEE: Charles Scawthorn, terns of sidewalk compression zones SPA Risk; John Eidinger, G&E Engi- and extension zones are relatively neering Systems; Mark Yashinsky, unique and may provide insights Caltrans) regarding transient ground motions in the very-near fault zone. Conversely, Utilities serving the affected area the ground deformation recorded in include potable water, wastewater, the sidewalks in the Browns Valley electric power, natural gas and com- area may be a result of secondary munications. There are no petro- ground deformation resulting from leum refineries or major pipelines Figure 16. Schematic of City of surface faulting, compacted earth fill, within the zone of MMI VI shaking, Napa water system overlaid on MMI and showing three sources (large dark blue circles) and main transmission lines, locations of distribution tanks (smaller circles) and damaged Montana “B” tank. The California Water Project’s North Bay Aqueduct, which feeds Barwick Jamieson WTP, is Table 2. City of Napa distribution piping–length of pipe (% in red) by age and shown as dashed light-dark blue material. Key: C900 = PVC, DIP = Ductile Iron Pipe, CI = Cast Iron, AC = (source: Charles Scawthorn, SPA Asbestos Cement, RCCP = Reinforced Concrete Cylinder Pipe, STL = Steel Risk). (source: Scawthorn, after City of Napa).

9 EERI Special Earthquake Report – October 2014

Material Breaks % Brks Brks/mile Figure 17. City of Napa water Asb. Cement 8 5% 0.23 system over- C900 (PVC) 2 1% 0.34 laid on PGA, Cast Iron 123 75% 0.82 showing loca- Concrete 1 1% 0.53 tions of breaks Duct. Iron 18 11% 0.16 and Montana Steel 3 2% 0.10 “B” tank (data: Other/Unknown 7 4% City of Napa; Total 163 100% map: Charles Scawthorn, Table 3. Number, percentage, and per mile breaks, SPA Risk). City of Napa Water Distribution system (data: City of Napa; table: Charles Scawthorn, SPA Risk).

but there are several major facilities breaks in the system; there were 163 • Alameda County WD – within the MMI V zone (see Figure breaks, 75% of which were in cast 1 truck crew 1). Transportation lifelines serv- iron pipe. Among the more significant • City of Fairfield – ing the affected area include roads breaks was that in the main transmis- 1 truck/ 2 crews and highways, rail, airports, marine sion pipe from the Milliken source, • CCWD – ports and ferry.(Eidinger, 2014). which was broken by a rock slide, 1 truck/crew Figure18. • EBMUD – Potable Water. The City of Napa’s 5 truck/crews water system, which serves approx- Of the 12 tanks in the system, one imately 80,000 persons, is shown in (termed Montana “B”) sustained sig- These crews arrived with their own Figure 16 and has three sources: nificant damage, Figure 19. The tank trucks and equipment fully stocked is an unanchored 67’ diameter, 37’ with spare parts. All were released • Lake Hennessy (31,000 A-ft), high circular welded steel tank with by August 29. The city estimates Water Treatment Plant (WTP, 20 corrugated iron (CGI) roof supported it spent about $200,000 on spare mgd, built1982) by redwood beams on steel columns. parts for repairs. The water sloshed with approximately • SWP/Barwick Jamieson WTP 6’ amplitude, damaging the roof. American Canyon reported no (21,900 A-ft pa entitlement, WTP There was no buckling of the walls, damage to its system, while the 20 mgd, built 1967) but some rocking was evidenced by City of Vallejo sustained approxi- motion at the outtake slip joint. The mately 51 distribution pipe breaks. • Milliken Reservoir (1400 A-ft), a tank drained immediately following seasonal backup source the event due to a nearby pipe break.

The distribution system includes While there were a relatively large 12 tanks and 337 miles of distri- number of breaks, and loss of pres- bution pipe, which is made up of sure at some locations, service was several types and vintages of pipe, maintained for much of the city due to as shown in Table 2. Table 3 and a decision by the city to continue the Figure 17 show the locations of flow from both Lake Hennessy and Barwick Jamieson sources. It was Figure 19. Montana “B” tank. later estimated that the total loss of Upper photo–roof damaged by water due to this policy was approxi- sloshing; lower photo-- outtake mately 100 Acre-feet. exhibiting evidence of motion at slip joint (photo: City of Napa). Pipe breaks were repaired relatively quickly, with half completed in less than five days, Figure 20. The City of Napa was aided in making repairs by regional utilities through the Cal- Figure 18. Milliken line, broken by WARN (www.calwarn.org ) system, rock slide (photo: City of Napa) as follows:

10 EERI Special Earthquake Report – October 2014

Figure 20. Left, water Type of Pipe Miles % system distribution pipe break ABSPlastic 2 0.7% repairs (%) vs. number Asb. Cement 124 45.9% of days following the earthquake (data: City Cast Iron 1 0.4% of Napa; chart: Charles Concrete 3 1.1% Scawthorn, SPA Risk). Polyvinyl chloride 61 22.6% Reinf. Concrete pipe 7 2.6% Table 4. Right, Napa Sanitation District Pipe Vitreous clay pipe 70 25.9% Material breakdown Other 2 0.7% (source: Napa Sanita- Total 270 100.0% tion District)

Napa Sanitation District. Napa’s damaged barrels that flowed to the the fuses to blow and the power sanitation district (NSD) provides sewers and then SWRF. The wine is outage. sewer service for 75,000 people acid and disrupted normal anaerobic over 23 square miles with a system bacterial processes in the digester, Approximately 70,000 PG&E of 270 miles of sewer lines (Table increasing biochemical oxygen customers had one or more power 4), 5,651 manholes, and three lift demand (BOD) to as high as 15,000 outages during and after the stations. NSD reported 11 breaks mg/l (normal is 175 mg/l), and upset- earthquake, with a peak around in its sewer mains, all in asbestos ting treatment operations for about 3.75 hours after the quake. Over cement pipes. Nine of these breaks 48 hours. Air was blown into the 99% of these customers had power are believed to have been along digester for 24 hours (using normal restored within 24 hours (Figure the fault trace, while two were due blowers), and the process recovered. 22). to water main breaks (causing soil No untreated water or solids were erosion and loss of support to the released to the environment. Natural Gas. The affected region sewer line). is traversed by two natural gas Electric Power. The affected region transmission lines (Figure 23). Napa’s wastewater is treated at the contains several 60 kV–230 kV trans- PG&E reported two non-hazardous 7 mgd (dry weather) Soscol Water mission lines and 30 substations, leaks on these lines, but no rupture Recycling Facility (SWRF), where Figure 21, as well as some relatively of line. there was sloshing and spillage at unique structures such as the Carqui- the sand filters. Additionally, minor nez Straits crossing structures. In the distribution system, PG&E cracking was observed in several reported no loss of service to reinforced concrete structures at the Damage to the distribution system customers due to damage to their plant. (12-21 kV), included 12 pole trans- facilities; 160 customers lost service formers, 15 cross arms, 63 spans of due to damage to customer facili- SWRF did not lose PG&E service, conductors, and 28 downed overhead ties. PG&E responded to 5,810 but wastewater treatment opera- wires (though no poles were dam- service “tags” (report of gas odor, tions were significantly disrupted aged). Initial investigations estimated leak, safety check) and performed due to an inflow of an estimated that more than 90% of all outages 2,818 relights (with 926 in Napa 334,000 gallons of wine spilled from were related to wire-wire contact of and 110 in Vallejo), which were all the electrified lines, which caused completed ~24 hrs following the

Figure 21. Affected region EHV electric system Figure 22. Number of customers without power, versus (source: Charles Scawthorn, SPA Risk) hours after the earthquake (source: TCLEE)

11 EERI Special Earthquake Report – October 2014

Figure 25. Napa airport with inferred fault trace in red (epi- center star), and mapped trace of W. Napa fault in black (base map: Virtual Earth; annota- tions: Charles Figure 23. Fault rupture, after- Scawthorn, SPA shocks and PGA intensities Risk). superimposed on PG&E map of natural gas transmission lines Telecommunications. Telecommu- shown as blue lines (trans- nications systems generally per- were also significantly delayed. mission data: PG&E; source: formed well. The AT&T building in (Trains, 2014) Charles Scawthorn, SPA Risk downtown Napa sustained damage to a concrete wall panel, attached Air. The Napa County airport to the building using eight bolted reported no damage to any of its angles, which fell due to connec- own facilities, although minor crack- tion failure during the earthquake ing was reported on one runway and disrupted power to the build- (see Figure 25). Operations were ing. Emergency generators did not suspended from normal opening work, but the equipment and opera- time (7:00 am) for 30 minutes to tions were sustained by battery allow inspection and then were systems. resumed. The airport lost normal commercial power, but backup Verizon reported no loss of ser- power functioned satisfactorily. vice; however, they had to bring in backup power for several cell The Air Traffic Control (ATC) tower towers. at Napa airport is owned and oper- ated by the Federal Aviation Admin- No disruption of 911 service was istration (FAA); it sustained no reported. structural damage, there was glass breakage in its main control room Rail. California OES reported that windows. Local ATC was not avail- the Union Pacific inspected its lines able for four days until a temporary Railroads within the Figure 24. and found no issues; BNSF opened tower was brought in; the temporary affected area, overlaid on PGA most tracks; Cal Northern Railroad tower will be required for several (source: Charles Scawthorn, reported no damage; and Sonoma- weeks, pending delivery of replace- SPA Risk). Marin Area Rail Transit (SMART) ment glass. Operations continued event. PG&E also reported 26 stopped trains running until at least without ATC, and pilots communi- priority leaks (blowing gas, immedi- Tuesday (see Figure 24). The Napa ate response), 425 non-hazardous Valley Railroad reported heavy leaks, 886 non-hazardous meter damage to its Napa Station. Amtrak reset leaks. PG&E inspected 76 reported its Capitol Corridor was gas regulators in the affected area, suspended for “a time;” its Los finding no damage. Angeles–Seattle Coast Starlight was held while track and bridges No information is currently avail- were inspected; its Northbound able regarding the presence, train No. 14 was stopped near performance, or impacts of seismic Emeryville, and the southbound No. shut-off valves. 11 stopped near Chico for several hours; and its California Zephyrs Figure 26. Sonoma Creek Bridge (photo: Mark Yashinsky).

12 EERI Special Earthquake Report – October 2014

Figure 27. lower photo--Napa Slough Bridge; upper photo--typ- ical damage to pile extensions on the Napa Slough Bridge (photos: Mark Yashinsky). Figure 28. Banging at abutments on the Napa River (W. Imola Ave) Bridges (photo: Mark Yashinsky). so the substructure was retrofit with large-diameter cast-in-steel shell against abutments (Figure 28). This (CISS) piles supporting the ends of kind of damage is a nuisance to the enlarged bent cap when it was repair, but it doesn’t normally affect widened in 1999 (Figure 26). The a bridge’s ability to carry traffic. bridge is two miles from the local agency-owned Napa Slough Bridge (Figure 27), which had a similar substructure, similar soft soil, and cated directly via radio, which is a similar level of ground shaking the normal procedure at airports during the earthquake. There was that do not have ATC. no damage to the Sonoma Creek Bridge while the Napa Slough Bridges. State-owned bridges in Bridge had serious damage (Figure the area had been retrofit in the 27). 1990s. Out of 412 state bridges in Figure 30. Fault offset across Solano, Napa, and Sonoma Coun- The ends of the pile extensions on State Route 12 (photo: Mark ties, 54 bridges had been retrofit- the Napa Slough Bridge had deep Yashinsky). ted and the others were screened cracks and spalls into the core and found not to be vulnerable. region. Fortunately, the #4 hoop The Napa River (State Route 37) The benefits of this retrofit pro- reinforcement at 12 inches was Bridge, a 33-span precast girder gram could be seen following the strong enough to hold onto the lon- bridge on flexible two-column piers earthquake. gitudinal reinforcement and prevent and stiff four-column piers, was built the failure of the piles. If the earth- in 1963 (Figure 29). The 1989 Loma The Sonoma Creek (State Route quake had been of longer duration, Prieta earthquake was centered 37) Bridge is a 22-two span the piles may have failed. 100 km away, but the bridge was precast girder bridge on battered damaged due to the long-period (tilted) and poorly confined pile Most of the damage to state bridges shaking on deep bay mud. The pre- extensions. This type of substruc- was due to opening and closing cast girders started to pull out of the ture had been identified as vulner- of expansion joints, and the bang- diaphragms, but fortunately didn’t able during the retrofit program, ing of wingwalls and barrier rails move far enough to collapse. The bridge was retrofitted in the 1990s with larger foundations, containing Figure 29. Retro- more piles, steel column casings, fitted Napa River and end diaphragms strengthened Bridge with large with transverse prestressing and foundations, steel concrete bolsters. column casings, and strengthened precast The ground motion during the girder connections South Napa earthquake was low, (photo: Mark Yashin- but the bridge shook enough to sky). damage the expansion joints at its crest. However, no primary member

13 EERI Special Earthquake Report – October 2014

family units. In Napa County, nearly 30% of the housing stock was built before 1959, while in Solano County only 20% of residences predate 1959. The median house price in Napa County is $460,000; in Solano County it is $290,000 (USA.com, n.d.a; USA.com, n.d.b). Napa County also has a significant population of mobile homes, many Figure 33. Foundation collapse in of which were damaged in the Salvador Mobile Estates northwest earthquake. of downtown Napa. Mobile home displaced in westerly direction Most single-family homes in the (photo: Mike Mieler). region are one- or two-story wood- frame structures with either wood or Napa and the surrounding region, stucco exterior siding. Many homes as far south as Vallejo (Fimrite, built before 1950 have cripple wall 2014). Chimney failures included Figure 31. Cripple wall failure of sin- foundations, where the first floor both crumbling of masonry and top- gle-story house west of downtown of the structure is elevated sev- pling of entire chimneys (see Figure Napa. House fell in northwesterly eral feet off the ground on short 32). Many masonry chimneys in direction (photo: Betsy Mathieson). perimeter walls that are vulnerable residential neighborhoods north of was damaged and the bridge was to collapse in earthquake ground downtown Napa had been removed quickly returned to service after shaking. The area surrounding or replaced before the earthquake, being briefly closed for inspection. downtown Napa has a high con- possibly due to damage from the centration of such structures, and 2000 Yountville earthquake. In the Roads. Road damage was due to several cripple wall failures were residential neighborhoods along the surface fault offset. Traffic was so observed (see Figure 31). Some West Napa fault, several relatively busy in Napa that vehicles were cripple wall structures had been new homes had concrete founda- allowed on roads with significant retrofitted prior to the earthquake, tion damage due to surface fault cracking (Figure 30). Fortunately, but we have not identified them all rupture (Bray et al., 2014). there was little vertical offset across or studied them in detail. In addition the West Napa Fault and the hori- to cripple wall distress and failure, Many mobile homes in Napa zontal offset was usually less than many residential masonry chimney County had extensive foundation a foot. failures were reported throughout damage as a result of earthquake ground shaking. Typical mobile Other transportation. No damage home foundations comprise stacked was reported at the Napa Marina concrete blocks that are vulner- (on the Napa River), the marine ter- able to collapse in an earthquake. minals in Vallejo, Martinez or Beni- An exterior survey of more than cia, or the ferry landing in Vallejo. 80 mobile homes (both damaged and undamaged) in the Salvador Performance of Structures Mobile Estates community in Napa revealed that nearly a quarter Housing of homes had either significant (Mike Mieler, Johns Hopkins University; permanent displacement or partial Janiele Maffei, CEA; Betsy Matheson, foundation collapse (see Figure 33). Exponent; Danielle Hutchings Mieler, In the Napa Valley Mobile Home ABAG; Larry Stevig, State Farm Insur- Park, earthquake shaking ignited ance; Warner Chang, IBHS) fires that destroyed four homes and damaged two. Following the The housing stock in Napa and earthquake, reconnaissance teams Solano Counties comprises mostly identified and briefly surveyed a Chimney collapse near single-family homes. Of the 207,000 Figure 32. small number of mobile homes downtown Napa. Chimney failed at housing units in the region, over whose foundations had been roof line of two-story Victorian house two-thirds are detached single- retrofitted with steel braces. They (photo: David McCormick).

14 EERI Special Earthquake Report – October 2014

masonry buildings (URMs) in the downtown area of Napa. Most buildings with retrofits appeared to perform well with respect to global life safety or collapse prevention, but a number of localized life safety hazards were identified. Damage was variable, but over 30 retrofitted URM buildings generally outper- formed the three remaining nearby unretrofitted buildings. Because interior access was not available for most buildings, interior damage and the extent of retrofit was only partially documented. Some cases certainly warrant detailed follow-up inspections to assess all structural and nonstructural damage, and to Figure 34. URM buildings observed Figure 36. Turret damage in retrofit- determine the details and perfor- by EERI team members/contributors ted stone masonry building (No. 12 mance of the retrofits. (source: Andre Barbosa). in Figure 34; photo: Matt Schoettler). Figure 34 shows the location of showed less foundation damage, severely damaging the cars parked URM buildings inspected by the but several instances of incom- underneath. Additional reconnais- team in the three to four days fol- plete or inadequate retrofit installa- sance is required to more fully lowing the earthquake. Buildings in tions were observed. More detailed understand the broader perfor- other portions of the city were not studies are recommended to verify mance of multi-family residences visually inspected. both the quality and performance throughout the region. of mobile home retrofits. Two historic retrofitted stone Unreinforced Masonry Buildings masonry buildings, the Vintner’s A limited number of multi-family (Andre R. Barbosa, Oregon State Uni- Collective (Figure 35) and the apartments have been surveyed versity; David McCormick, SGH; Marko Goodman Library (Figure 36), following the earthquake, includ- Schotanus, Rutherford+Chekene; Bill posed life-safety risks from falling ing one with a potential soft-story. Tremayne, Holmes Culley; Fred Turner, hazards. Interestingly, these were In general, only minor structural California Seismic Safety Commission) the only two buildings that were damage was observed, though reported to have suffered minor at one apartment complex sev- Several teams performed rapid damage in the 2000 Yountville eral detached carports collapsed, visual inspections of unreinforced earthquake (Miranda and Aslani,

Figure 37. Out-of-plane failure in URM building (No. 1 in Figure 35. Historic stone masonry building damage Figure 34; photo: Andre Barbosa). (No. 21 in Figure 34; photo: Andre Barbosa).

15 EERI Special Earthquake Report – October 2014

Figure 38. Out-of-plane failure in two-wythe masonry Figure 39. In-plane shear failure of masonry piers wall with brick veneer connected with straight adhesive (No. 22 in Figure 34; photo: Andre Barbosa). anchors (No. 4 in Figure 34; photo: Karl Telleen).

2000), while all other URM build- cal integrity of the building. The front. In-plane shear cracks were ings were reported as undamaged damaged turret received limited clearly visible. Wall-to-floor ties in that event. retrofit due to historic preserva- performed well. However, the tion issues. Subsequent review out-of-plane demand exceeded Figure 35 shows the partial of the seismic retrofit drawings the out-of-plane flexural capacity collapse of the front wall of the indicated that the retrofit included of the exterior walls at the second Vintner’s Collective building. the addition of two concrete shear story. Though there is interior wood walls in the transverse direction framing with hold-downs, no (one interior and the other located Several buildings had compre- connectivity to the masonry was at the front façade), and perimeter hensive retrofits. Though these observed. It is not clear whether floor and roof diaphragm ties. The retrofits generally appeared to the wood framing was part of the only documented intervention at have performed well, some build- retrofit and if it was intended to the turret tower was the addition ings were red-tagged immediately function as a secondary grav- of a 5” thick concrete slab at the after the earthquake mainly due ity system to protect the interior. mid-height. to falling hazards. In one URM In-plane shear cracks in the north building with a comprehensive and south walls (not shown) were Out-of-plane failures were retrofit, we observed roof and also observed, but damage was observed in several buildings, ceiling-to-wall anchors with thru- moderate. The Goodman Library but in-plane shear failures were (Figure 36) was retrofitted with less prominent. Figure 37 shows a 2004 design. While roof dia- the out-of-plane failure in an phragm strengthening and parapet unretrofitted building adjacent to bracing was visible, the extent of a parking area where a car was other retrofit measures was hidden destroyed by the falling walls to avoid compromising the histori- and parapets. Figure 38 shows damage to a corner of a building that was retrofitted in 1984, well before the city and the state had adopted minimum retrofit codes. The exterior wall was a two-wythe wall with a brick veneer. The retrofit included straight adhesive anchors that were embedded only in the collar joint and did not perform as intended.

Figure 39 shows damage to Retrofitted building with Figure 41. Wall damage caused Figure 40. a building that had an interior shifted cornice stone (No. 14 in by exit stair (No. 14 in Figure 34; braced frame along the open Figure 34; photo: Marko Schotanus). photo: Bill Tremayne).

16 EERI Special Earthquake Report – October 2014

Figure 42. Comprehensive retrofit with minor damage in parapets (left), which led the building to be yellow tagged since the building was still accessible from the back (photo: Bret Lizundia); and (right) inte- rior view showing no business interruption (No. 20 in Figure 34; photo: Bill Tremayne). bolts on the east façade and steel observed at the shared URM ary support posts to roof trusses, concentric braced frames at the wall. A relatively modern steel and perimeter roof diaphragm- first and second story along the framed stair was supported at to-wall anchorage. These retrofit front wall (Figure 40). The only the mid-height landing from the measures were successful even notable damage at the front of shared wall, and was also rigidly though there was front and rear the building was a cracked/loose attached at the top landing. The parapet damage, making access cornice stone at the center of stair stringers appear to have from the front impossible. the wall, which created a falling acted as braces, inducing out-of- hazard and required repair. The plane demands on the URM wall, A building located less than 200 building’s tenants reported that the causing the localized out-of-plane yards from the Napa netquake only interior damage was some failure, as shown in Figure 41. station that recorded a peak- broken wine bottles. Interestingly, ground acceleration of 0.61g the front entrance of the build- Figure 42 shows another suc- seems to have performed as ing was red-tagged, though the cessful retrofit-- a single-story expected (Figure 43). Damage building was accessible from the URM structure with a single consisted of cracks on the non- rear, where localized damage was owner and multiple tenants. structural façade wall elements The retrofits consisted of steel near the brace base connections, moment frames at the front of while structural elements also the building, shotcrete overlay showed damage in the chevron at the rear interior wall, second- braces and gusset plates which

Figure 44. Steel frame with masonry infills: left--rocking wall pier with perma- nent offset (photo: Bill Tremayne); right-- shear failure in wall pier (No. 26 in Figure 34; photo: Andre Barbosa).

Figure 43. Buckled brace in URM with steel braced frame retro- fit (No. 19 in Figure 34; photo: Andreas Schellenberg).

17 EERI Special Earthquake Report – October 2014

Figure 45. Observed damage in Queen of the Valley Hospital (photos: OSHPD). showed localized buckling at when comprehensive retrofits the first story. This building was are implemented. Of the over allowed to be occupied 30 hours 30 URMs in Napa that had been after the earthquake. retrofitted, ages of the retrofits varied from over 40 years ago to A few damaged buildings were the present. Most were intended identified as having steel or con- to comply with the various edi- crete framing with URM infills. The tions of the Uniform Code for post office building in downtown Building Conservation with city Napa, a steel frame building with amendments and/or the Califor- Figure 47. Top and bottom, store- URM infill walls, showed shear nia Historical Building Code, as front damage (photos: OSHPD). cracking in end-wall piers, such as well as applicable sections of the the stair-stepped bed joint sliding California Building Code for new systems and details, provided that seen in Figure 44, interior/slender construction. Several retrofits were detailed information is made avail- wall piers damage, and permanent completed many years before the able. Some key vulnerabilities offset in sliding bed-joints. city had adopted its mandatory were not addressed adequately: retrofit ordinance. This offers a (a) parapets and tops of walls The performance of URM struc- great opportunity to investigate the were left vulnerable; (b) corners tures confirmed their high seismic performance of different retrofit of buildings at the roof level vulnerability, and demonstrated appeared to be more susceptible the difficulty of addressing all to damage, likely due to the lack potential falling hazards even of confinement and overburden as well as deformation incompat- ibilities between orthogonal walls; and (c) some adhesive anchors in older retrofits--particularly with short and straight embedments- -intended to connect walls to floor and roof diaphragms did not perform well. Recent acceptance criteria for adhesive anchors prohibit such short and straight embedments. Stone masonry performed below average, even when retrofitted. Figure 46. Left and right, precast beam and diaphragm connection damage at one location (photos: OSHPD).

18 EERI Special Earthquake Report – October 2014

Hospitals walls in the main hospital building (CBS SF, 2014). Damaged facili- (Ali Sumer, OSHPD) (Figure 45). ties were concentrated northwest of the epicenter, west of Highway Six general acute care hospital In the main hospital building, built 29, for about ten miles north of facilities (comprising 58 buildings) in 1957, two elevators were out- the epicenter. Other wineries had and 16 skilled nursing facilities of-service, and there was some only minor damage to bottles and were within 25 miles of the epi- damage in the precast floor slabs/ contents in the tasting facilities. center. The Queen of the Valley beams (see cracks in Figure 46). In Medical Center (QVMC) was the the South Nursing Wing building, The earthquake risk profile of a closest to the fault trace (2.3 miles the storefront bowed in and off the winery is varied based on the time away) and had the most damage. top track (Figure 47). The stucco of year. Direct damage and loss of A few buildings lost limited func- exterior walls at the ICU rooms life was minimized due to the time tionality temporarily due to minor pulled down from upper deck at of day and of year. In late August structural and/or nonstructural the top of wall approximately ½” the wineries are preparing for damage. The facility was on emer- causing disruption of services in crush, with most of the wine tanks gency power immediately after these rooms. In the North Acute and barrels empty, ready to receive the event due to loss of power. Care building, a humidifier above newly crushed grapes and fer- Three buildings at the QVMC were the corridor ceiling leaked causing mented wines. Had the earthquake yellow tagged by OSHPD engi- water damage to the ceiling tiles struck a couple months later, the neers, and the rest of the buildings underneath. damage to the production facilities were green tagged. and loss of wine would have been Wineries considerably higher. The QVMC buildings had seis- (Joshua Marrow, Partner Engineering mic joint damage, plaster cracks, and Science, Inc.; Andy Yiu, Partner Early analysis reveals damage dropped ceiling tiles, and content Engineering and Science, Inc.) to wine barrel storage at facilities damage in several rooms. The located in areas with a PGA greater most extensive ceiling damage The Napa Valley has approximately than 0.20g, less than ten miles from was in the North Acute Care Corri- 400 wine production facilities, about the epicenter. Loss of wine stored dor building near the seismic joints 300 of which have been built since in barrels was still being tabulated. at the third floor. A ¾” diameter 1966. An estimated 50 wineries Damage to wine barrel storage water line break caused water sustained measurable damage damage to a few nonstructural to tanks, barrels and/or buildings

Figure 50. Stainless steel wine tank ruptured anchors, shifted Figure 48. Collapsed stacks of Figure 49. Collapsed barrel stacks 12inches, and buckled tank wall barrels on “two-barrel racks” (top); leaning on interior column (top); a (bottom); tank-supported catwalk stable stacks of barrels on four- column knocked out of plumb by collapsed when tank (off to the left) barrel racks (bottom) (photos: Andy collapsed barrels (bottom) (photos: collapsed (top) (photos: Joshua Yiu, Joshua Marrow). Andy Yiu, Joshua Marrow). Marrow).

19 EERI Special Earthquake Report – October 2014

performed well, with no reported Figure 52. lower photo--locations damage. of fires in NVMHP (damaged buildings outlined in red) ; upper Full 600-pound barrels from col- photo--panoramic image of dam- lapsed stacks damaged interior aged mobile homes (photo: Virtual building columns and collapsed the Earth; annotations: Charles Scaw- exterior wall of a facility 10 miles thorn, SPA Risk). north in Oak Knoll (Figure 49). Interior stud-frame partition walls separated regions of collapsed bar- rels, reducing the total collapsed Figure 51. Fires and approxi- mate times overlaid on PGA (half barrel count and wine loss. shaded triangle indicates street number unknown) (source: Charles Stainless steel wine tanks used Scawthorn, SPA Risk). in the wine industry are gener- ally not anchored or inadequately was significant in wineries using anchored. Proper anchorage the two-barrel portable steel barrel design is complicated by the tight rack system. Stack collapse was spacing of the tanks, minimal con- not directly tied to the height of the crete edge clearance and anchor A more complete assessment of stack (up to six barrels tall, 18-feet embedment, and thin bottom winery damage is on-going and will long). The vulnerability of the two- course tank walls. Damage lim- be published as part of the FEMA- barrel rack was previously demon- ited to full tanks with limited base funded Applied Technology Council strated in the 2000 Yountville and anchorage. The majority of tanks publication ATC-66-8 in early 2015. 2003 San Simeon earthquakes. were empty in preparation for the The two-barrel racks tend to slide harvest and crush in Septem- Emergency Response off the supporting barrel below and ber. At a facility located 9.5 miles result in the collapse of the stack directly north of the epicenter, three Fire Following Earthquake above (Figure 48, top). Barrel 20,000-gallon tanks were dam- (Charles Scawthorn, SPA Risk) stacks using the four-barrel rack aged beyond repair, resulting in sustained damage limited to ejec- loss of 75% of the wine (Figure 50, Fire sites were surveyed on the day tion of the top-level barrels, with bottom). At the same facility, the following the earthquake (August no reported stack collapse (Figure tank failure resulted in partial col- 25), and senior officers of the Napa 48, bottom). Pyramid stacks and lapse of the catwalk and ruptured Fire Department (NFD) were inter- other proprietary storage methods PVC cooling lines (Figure 50, top). viewed. A complete list of incidents to which the NFD responded was No. Time of report Location Description (see below) not available at the time of the (approx) interview, but fires attributable to 1 0330 Orchard Ave Napa Valley Mobile Home Park (NVMHP) – actually two ignitions – see narrative the main shock are summarized in 2 0400 Laurel St. (no. street 2 story, 2 unit residence, roof collapse, Table 5 and shown in Figure 51 and number started fire Figure 52. 3 0500 162 Robin at Solano Dbl wide home The Orchard Avenue fire was the 4 0630 1990 Trower Smoke inside structure largest in the earthquake. First 5 0730 770 Lincoln x Soscol Electrical fire in substructure of a mobile dispatch was of T1 to a report of home gas odor, but en route T1 observed 6 1200 4072 Rohlffs Way x Fair Kitchen fire in single story multi-unit senior a fire in the Napa Valley Mobile housing complex Home Park (NVMHP) off Hwy 29 Table 5. Fires attributed to the main shock (source: NFD). 20 EERI Special Earthquake Report – October 2014 at Orchard Road, and diverted be circumvented. Its use for pre- The shelter population grew from to this incident. T1 encountered venting access to buildings, as well eight people the first night to nearly a broken water main spewing as for closing streets, caused some 50 people a week later (City of water at the entrance to the park confusion among residents. Napa, 2014; Yune, 2014a; Napa and proceeded to enter. T1 then Valley Register, 2014). The shelter encountered a single structure Within several days of the earth- recorded 436 overnight stays over fire at 313 Mark Way, with the quake, city officials replaced the the span of two weeks, and closed structure 50% involved; simultane- caution tape with chain link fenc- on September 8 as demand sub- ously, T1 observed a second fire at ingbarricades and scaffolding. The sided (Rasmus, 2014). On Sep- 317 Patty Way, which was 100% officials had to weigh their respon- tember 8, Napa City and County involved and impinging on neigh- sibility to protect the well-being of opened the Local Assistance boring buildings, see Figure 52 residents while recognizing that Center, a one-stop assistance depot top). Wind conditions were calm. barricades in streets could block with representatives from more traffic and affect businesses. When than 50 public and private agencies Approximately 20 minutes into the possible, the chain link barricad- that provide earthquake recovery incident (at about 0400), Water ing was placed on the sidewalk assistance and information to resi- Tenders 15 and 25 arrived from in order to keep the streets pass- dents and business owners (Yune, the Napa County Fire Department. able. This practice recognized 2014b). NFD E6 had also arrived and sup- the falling hazard, but not the pressed the Mark Way fire. T1 and potential for debris to be flung in In Vallejo, the Red Cross opened WT 25 similarly suppressed the aftershocks. Scaffolding next to a an evacuation shelter on August 24 Patty Way fire. damaged building partially col- at the Florence Douglas Center. On lapsed on October 1st windy day, account of limited initial demand for At 1990 Trower there was a report suggesting the need for engineered the services provided the Vallejo of smoke inside. At this site, designs and strict regulation of shelter closed soon after its open- which is a restaurant, employees temporary structures to ensure their ing but reopened three days later reported some equipment had stability and protective capability. to deal with growing demand and fallen onto other equipment in Recent California Building Offi- remained opened until September the kitchen, causing a call to the cials, CALBO, (2013) guidance on 5, when the Red Cross transited fire department. No significant cordoning and barricading dam- the clients in the Vallejo Shelter into damage. aged buildings recommends placing long-term housing (American Red either “hard barriers “ (designed Cross, 2014; St. John and Nelson, Rohlffs Way was a report of smoke for impact loads) immediately 2014; Napa County Red Cross, in a kitchen area of a senior citi- adjacent or “soft barriers” at “up 2014). zens residence. to 1.5 times the building’s height” away from it. In most cases, this Economic Impact As reported above, the Napa necessitates installing hard bar- County FD responded quickly with riers or placing barricades in the Losses and Insurance water tenders. By noon, two OES street. The CALBO guidance was (Mike Mieler, John Hopkins University) strike teams had arrived in Napa. developed following experiences in Christchurch, New Zealand, where In California, less than 10% of Barricading dozens of passersby were killed homeowners and businesses with (Danielle Hutchings Mieler, ABAG; when brick debris from damaged property insurance have earth- Ibrahim Almufti, Arup; Janiele masonry buildings was flung into quake coverage (Buck et al., 2014). Maffei, CEA; Marko Schotanus, streets during aftershocks. In Napa County, less than 6% of Rutherford+Chekene; Bill Tremayne, homeowners and renters have Holmes Culley; Fred Turner, California Shelters earthquake insurance (Buck et al., Seismic Safety Commission) (Mike Mieler, John Hopkins University) 2014; Carrns, 2014; EQE CAT, 2014). The California Earthquake In the immediate aftermath of the Following the earthquake, the Authority (CEA) estimates that earthquake, city officials used American Red Cross established approximately 15,000 of its poli- yellow caution tape around the an overnight shelter for displaced cyholders may have experienced most hazardous buildings to keep residents in Napa at the CrossWalk moderate to strong shaking from people away from falling debris. Community Church which was the earthquake (CEA, 2014). While This was a temporary measure, opened by 10am on August 24 it is still too early to understand the and the caution tape could easily (Napa CountyRed Cross, 2014). earthquake’s full economic impacts,

21 EERI Special Earthquake Report – October 2014

a preliminary analysis by EQECAT Figure 54. places the insured losses between A red- $500 million and $1 billion, though tagged business interruption costs and building contents damage could push the closed due figure higher (EQE CAT, 2014; to hazards Pender, 2014a; White, 2014). A posed by report by RMS caps the insured an adjacent losses at $250 million (Pender, building 2014b). (photo: Fred Turner). The City of Napa estimates the earthquake caused at least $300 million in damage to privately owned homes and commercial properties, and $58 million in damage to public infrastructure (Pender, 2014b; Kane, 2014). part of the declaration, low-interest ten. However, in the days after the Damage is expected to exceed disaster loans from the U.S. Small earthquake, the business com- $5 million in Vallejo and $4.5 mil- Business Administration (SBA) munity put out a call for residents lion in Sonoma County (Fimrite, are available to private, nonprofit to come downtown and patronize 2014; St. John and Nelson, 2014; organizations; the loans pro- open businesses. By the evening Pender, 2014b; Kane, 2014). On vide up to $2 million to repair or of the day following the quake, res- September 11, President Obama replace damaged or destroyed taurants were full and many people declared a partial major disaster real estate, machinery and equip- were strolling around downtown. for the quake, providing public ment, inventory, and other business A tourist industry collaborative- assistance for both emergency assets (Wyatt, 2014). However, -including Napa County economic work and the repair or replace- the disaster declaration does not officials, hotels, and wineries- ment of disaster-damaged public include individual assistance to -broadcast that Napa was still facilities (Napa Local Assistance private citizens and households for open for business. Social media Center, 2014). Additionally, as disaster-related damage, because including Twitter and Facebook the federal declaration process for were used. Tasting rooms in most individual assistance is currently of the wineries around Napa were under review. re-opened the day after the earth- quake, despite substantial damage Business Interruption to their inventory. (Ibrahim Almufti, Arup; Danielle Hutch- ings Mieler, ABAG; Lauren Biscombe, In many cases, particularly for URM Arup) and non-ductile concrete buildings with significant damage, the deci- Business interruption in Napa was sion to red tag was fairly straight- primarily caused by structural or forward since a life-safety hazard nonstructural interior damage that was readily apparent. The extent of triggered the assignment of yellow downtime for these businesses will or red tags. In many cases signifi- likely be considerable as owners cant exterior damage also caused must determine whether their build- adjacent buildings, which were oth- ings are even repairable. erwise undamaged, to be yellow or red-tagged. Businesses could not In cases where there was visible reopen until sufficient repairs were nonstructural damage but little to Figure 53. The metal studs sup- porting this stucco façade pulled done to merit a green tag. no evidence of structural damage away from the floors. The steel (either because there was no connection restraints were bent Downtown Napa was hit hardest, damage or because it was hidden and the screws were torn out with many businesses still closed by nonstructural components), (photo: Lauren Biscombe). at the time this report was writ- buildings generally were yellow-

22 EERI Special Earthquake Report – October 2014

Storefront glazing broke in many limbo as their ability to re-open is businesses. In some cases, large generally out of their control. Some shards of glass still remained and were reinforcing their roofs to pre- posed a life-safety hazard which vent masonry bricks from adjacent necessitated a yellow tag. Lami- buildings falling through in the nated glazing would likely have hopes that they would be awarded performed better and avoided a a green tag. yellow tag. There were several instances of significant façade In light of these “adjacency” issues, damage, even to newer buildings cities may want to assess whether like the Andaz Hotel, as noted resilient central business districts above. In one case, the steel could be created to minimize eco- connections of the metal studs nomic impacts. This would entail supporting a stucco façade of a retrofitting structurally vulnerable three-story office building pulled buildings and upgrading façades out of the floors, causing the on existing buildings. It would building (steel moment frame built also incorporate enhancements recently) to be red-tagged (Figure to achieve “beyond code” perfor- Figure 55. Toppled heavy shelving 53). There was also damage to mance objectives for new buildings, unit in a toy store (photo: Ibrahim mechanical equipment on the roof including additional requirements Almufti). of this building that did not trig- for new façades. While utility tagged. In many cases, business ger the red tag, but it would have disruption was not a major contribu- owners were left to wonder why contributed to business interruption tor to business downtime in Napa, their building was tagged a certain nonetheless. Stronger equipment improvements to utility and other way and how they could resolve anchorage could have prevented infrastructure would also support their status. This was indicative of some of the damage. Damage to resilient business districts. the fact that the tagging process is other nonstructural components ultimately based on the judgment was less extensive and did not Most owners in Napa reported of the individual evaluator. The contribute to tagging for this earth- damage to building contents and placards provided no information quake. This included relatively inventory, and while this contributed on follow-up contacts. minor cracking of partitions and to financial losses, it generally did some displacement of acoustic not cause extensive business inter- Several buildings were yellow- ceiling tiles. ruption since the damage did not tagged due to potential electrical trigger a yellow or red tag. Since hazards caused by water damage When business owners did not the earthquake struck early on from broken sprinkler pipes; it is own the building in which they Sunday morning when many busi- not clear whether the earthquake were located, the initiation of nesses were closed, many owners accelerations directly caused the repairs was delayed until the build- took the day to clean up and were pipes or sprinkler heads to break ing owner decided how to proceed, able to re-open on Monday if their or whether the breaks resulted contributing to business downtime. building was otherwise undam- from interaction with other building It was not clear what the con- aged. Of more concern are the components. This affected some tractual obligation of the building injuries that could have resulted Napa County buildings and two owner is in terms of making repairs from content damage to customers hotels, the Andaz and the Westin in a timely fashion. and staff had the earthquake struck Verasa. The Andaz Hotel had during business hours. Inside water damage as well as damage Some undamaged buildings were offices many downed file cabinets to its stone façade that was a life- also yellow or red tagged because and heavy bookshelves landed safety hazard to passersby and adjacent buildings posed a life- squarely on office chairs that would required barricading. The Andaz is safety hazard either from falling have been occupied during the day. set to re-open in early November, masonry bricks or significant A printer was thrown approximately and the Westin Verasa is re-open- façade damage (Figure 54). It may 3 feet from the table on which it had ing parts of the hotel in stages, be appropriate to introduce a new been sitting. At a toy store in down- with a plan to be fully operational tag color for this scenario to help town Napa bookshelves fell into by early December. avoid confusion for evaluators and the aisles (Figure 55); had children for owners. The status of many of been in the store, they could have these businesses is currently in been badly injured. The single fatal-

23 EERI Special Earthquake Report – October 2014

ity from the earthquake was caused (University of Hawaii), Eric Field- conclusions, or recommendations by a falling television. These types ing (NASA JPL), Margaret Glasscoe expressed herein are those of the of injuries could be prevented by (NASA JPL), Craig Glennie (Univer- authors and do not necessarily anchoring heavy building contents; sity of Houston), Les Harder (HDR), reflect the views of the NSF. currently this is not required by the Wayne Haydon (CGS), Suzanne building code. Hecker (USGS), Chris Hitchcock This reconnaissance effort benefit- (InfraTerra), Tom Holzer (USGS), ted further from collegial interac- Acknowledgements Ken Hudnut (USGS), Michael tions with members of a variety of Jewett (Miller Pacific), Keith Kelson organizations: California Earthquake Any opinions, findings, conclusions, (USACE), Jeremy Lancaster (CGS), Clearinghouse; California Depart- or recommendations expressed Jim Lienkaemper (USGS), Andy Lutz ment of Transportation (Caltrans); herein are those of the authors and (InfraTerra), Max Mareschal (CGS), California Division of Safety of do not necessarily reflect the views Alexander Morelan (UC Davis), Mike Dams (DSOD); California Highway of EERI, authors’ organizations, or Oskin (UC Davis), Jessica Murray Patrol (CHP); California Office of sponsors. (USGS), Susan Owen (NASA JPL), Emergency Services (OES); Cali- Jay Parker (NASA JPL), Ante Perez fornia Seismic Safety Commission Specific acknowledgements for (CGS), Alexandra Pickering (USGS), (CSSC); California Strong Motion each of the report sections are Fred Pollitz (USGS), Carol Prentice Instrumentation Program (CSMIP); listed below. (USGS), Jared Pratt (RGH Consul- City of Napa Public Works; Cotton, tants), Cindy Pridmore (CGS), Ron Shires & Associates, Inc. (CSA); Clearinghouse Rubin (CGS), Carla Rosa (USGS), County of Napa Public Works; Kevin Ryan (Ryan Geological Con- California Department of Water EERI works closely with its manag- sulting), David Schwartz (USGS), Resources (DWR); Earthquake ing partners in the California Earth- Gordon Seitz (CGS), Robert Sickler Engineering Research Institute quake Clearinghouse and would (USGS), Mike Silva (CGS), Nicholas (EERI); ENGEO, Inc.; Fugro, Inc.; like to acknowledge particularly Sitar (UC Berkeley), Jenny Thorn- GEI Consultants; HDR Engineering, the leadership of Anne Rosinski of burg (CGS), Jerry Treiman (CGS), Inc. (HDR); NASA Jet Propulsion the California Geological Survey, John Tinsley (USGS), David Trench Laboratory; Pacific Gas and Electric along with the contributions of Luke (Fugro), Chad Trexler (UC Davis), Company (PG&E); University of Blair of the U.S. Geological Survey, John Wesling (OMR), Donald Wells California, Davis; University of Cali- Kevin Miller of the California Office (AMEC), Mark Wiegers (CGS), Sang- fornia, Los Angeles; and U.S. Army of Emergency Services, and Fred Ho Yun (NASA JPL), Dana Zaccone Corps of Engineers (USACE). Turner of the California Seismic (GeoVit) Safety Commission. The ultimate Lead Authors are listed in the report; success of the clearinghouse is Geotechnical Engineering additional Contributing Authors due to the contributions of all the follow: N. Abrahamson (PG&E), volunteers who passed through The geotechnical response to the N. Avdievitch (USGS), T. Bayham and/or contributed over 2000 data earthquake was a highly collabora- (ENGEO), M. Bennett (USGS), points and records through the tive effort, with significant contribu- Y. Bozorgnia (UC Berkeley), D. online tools. tions from members of the following Branum (CGS), B. Brooks (USGS), organizations: Geotechnical Extreme C. Brossy (Fugro), B. Bryant (CGS), Geosciences Events Reconnaissance (GEER) M. Buga( Fugro), H. Carlosama Association; California Geological (UC Berkeley), B. Chiou (Caltrans), Nikita Avdievitch (USGS), Mike Survey (CGS); Pacific Earthquake B. Collins (USGS), R. Darragh Bennett (USGS), Dave Branum Engineering Research Center (Pacific Engineering and Analysis), (CGS), Jonathan Bray (UC Berke- (PEER); U.S. Geological Survey C. Davenport (CGS), M. Delat- ley), Ben Brooks (USGS), Cooper (USGS); and the University of Cali- tre (CGS), S. DeLong (USGS), A. Brossy (Fugro), Bill Bryant (CGS), fornia, Berkeley (UCB). The work of Donnellan (NASA – JPL), D. Dreger Mike Buga (Fugro), Julien Cohen- the GEER Association is based upon (UC Berkeley), U. Eliahu (ENGEO), Waeber (UC Berkeley), Brian work supported by the National Sci- Y-Nhi Enzler (California Division of Collins (USGS), Clif Davenport ence Foundation (NSF) through the Safety of Dams), T. Ericksen (Univ. (CGS), Marc Delattre (CGS), Steve Geotechnical Engineering Program of Hawaii), E. Fielding (NASA – DeLong (USGS), Andrea Don- under the leadership of Dr. Richard JPL), S. Foti (Politecnico di Torino), nellan (NASA JPL), Doug Dreger Fragaszy through Grant No. CMMI- M. Gardner (UC Berkeley), M. (UC Berkeley), Todd Ericksen 0825734. Any opinions, findings, and Glasscoe (NASA – JPL), C. Glen-

24 EERI Special Earthquake Report – October 2014 nie (Univ. of Houston), C. Gutierrez Gas & Electric, Verizon, California Bray, J.D., A. Rodriguez-Marek, and (CGS), G. Harris (HDR), W. Haydon Public Utilities Commission, ASCE J.L. Gillie, 2009. “Design Ground (CGS), S. Hecker (USGS), C. Hitch- Technical Council on Lifeline Earth- Motions Near Active Faults,” Bulletin cock (InfraTerra), D. Hiteshew (City quake Engineering (TCLEE), EERI/ of the New Zealand Society for Earth- of Vallejo), J. Hollenback (PEER/ California Earthquake Clearinghouse, quake Engineering, 42 (1). UC Berkeley), T. Holzer (USGS), M. EERI and PEER staff. Jewett (Miller Pacific), P. Johnson Bray, J., et al., editors, 2014. (CSA), J. Lancaster (CGS), J. Lien- Performance of Structures, Emer- Geotechnical Engineering Recon- kaemper (USGS), Y. Lu (UC Berke- gency Response, and Economic naissance of the August 24, 2014 M6 ley), A. Lutz (InfraTerra), J. Macedo Impacts South Napa Earthquake. Report of (UC Berkeley), S. Mahin (UC the NSF-Sponsored GEER Associa- Berkeley), M. Mareschal (CGS), C. Lead Authors are listed in the report; tion, California Geological Survey, Markham (UC Berkeley), S. Mazzoni additional Contributing Authors follow: Pacific Earthquake Engineering (UC Berkeley), M. McAuley (Califor- Adam Azofeifa (Holmes Culley), Brian Research Center, and U.S. Geologi- nia Highway Patrol), A. Morelan (UC Olson (Tipping Mar), Jonas Houston cal Survey,.Report No. GEER-037, Davis), S. Muin (UC Berkeley), M. (Holmes Culley), , Andreas Schel- September 15. http://www.geeras- Oskin (UC Davis), S. Owen (NASA – lenberg (PEER/UC Berkeley), Matt sociation.org/GEER_Post%20EQ%20 JPL), M. Panagiotou (UC Berkeley), Schoettler (PEER/UC Berkeley), Karl Reports/SouthNapa_2014/GEER_ J. Parker (NASA – JPL), A. Perez Telleen (Maffei Structural Engineer- SouthNapa_9-15-2014_reduced.pdf (CGS), M. Perlea (U.S. Army Corps ing), Zhiqiang Chen (UMKC), Steve of Engineers), V. Perlea (U.S. Army Pryor (Simpson Strong-tie), Abra- Bryant, W.A., 1982. West Napa fault Corps of Engineers), A. Picker- ham Lynn (Cal Poly + Degenkolb zone and Soda Creek (East Napa) ing (USGS), J. Pratt (RGH Con- Engineering), Glen Granholm (ETC fault, Napa County. California Division sultants), C. Prentice (USGS), C. Building & Design), Post-Disaster of Mines and Geology Fault Evalua- Pridmore (CGS), C. Rosa (USGS), Performance Observation Com- tion Report FER-129, scale 1:24,000. R. Rubin (CGS), B. Schmidt (Cali- mittee of the Structural Engineers fornia Highway Patrol), D. Schwartz Association of California, Erol Kalkan Bryant, W.A., compiler, 2000, Fault (USGS), G. Seitz (CGS), P. Shires (USGS), Erika Fischer (Purdue Uni- number 36b, West Napa fault, Napa (CSA), R. Sickler (USGS), M. Silva versity). County Airport section, in Quaternary (CGS), M. Stanley (HDR), J. Stew- fault and fold database of the United art (UCLA), J. Thornburg (CGS), J. This report was edited by Sarah States. U.S. Geological Survey web- Tinsley (USGS), J. Treiman (CGS), Nathe. Lay-out by Pam McElroy. site: http://earthquakes.usgs.gov/haz- D. Trench (Fugro), C. Trexler (UC ards/qfaults; accessed 09/22/2014. Davis), B. Vanciel (City of Vallejo), References S. Wang (UC Berkeley), J. Weber Buck, C., L. Philip, and P. Reese, (HDR) D. Wells (AMEC), M. Wieg- American Red Cross, 2014. “Ameri- 2014. “Napa’s 6.0 rumbler brings up ers (CGS), S. Yun (NASA – JPL), D. can Red Cross opens evacuation another queasy topic: Earthquake Zaccone (GeoVit). centers following Napa quake,”. insurance,” The Sacramento Bee, August 24. http://www.redcross. August 26. http://www.sacbee.com; Lifelines org/news/article/American-Red- accessed September 24, 2014. Cross-Opens-Evacuation-Centers- Alex Kwasinski (University of Texas), Following-Napa-Quake; accessed CALBO, 2013. “CALBO’S Interim John Andrews (Department of Water September 23, 2014. Guidance for Barricading, Cordoning, Resources), Anshel Schiff (Precision Emergency Evaluation, and Stabili- Measurements), Alex K Tang (L&T Ancheta, T. D., et al., 2014. “NGA- zation of Buildings with Substantial Consulting), Tom O’Rourke (Cor- West2 Database,” Earthquake Spec- Damage in Disasters.” California nell University), Craig Davis (Los tra, V, 30(3), pp. 989-1005. Building Officials, November. Angeles Department of Water and Power), Majid Sarraf (TTG), City Bakun, W.H., 1999. “Seismic activ- Carrns, A., 2014. “After Napa jolt, of Napa (Fire Department, Depart- ity of the San Francisco Bay region,” quake-proofing your homeowner’s ment of Public Works, Water Divi- Bulletin of the Seismological Society insurance,” The New York Times, sion), City of Vallejo (Department of of America, 89, pp. 764-784. August 29. http://www.nytimes.com; Public Works, Fire Department), City accessed September 24, 2014. of American Canyon (Department Bozorgnia, Y., et al., 2014. “NGA- of Public Works), Napa Sanitation West2 Research Project,” Earthquake CBS SF, 2014. “Napa Valley Wine District, Napa County Airport, Pacific Spectra, V, 30(3), pp. 973-987. Industry Reports $80.3 Million

25 EERI Special Earthquake Report – October 2014

Damage Toll from Earthquake,” Sponsored GEER Association Team, Langenheim, V. E., R.W. Graymer, September 9. http://sanfrancisco. California Geological Survey, Pacific and R.C. Jachens, 2006. “Geo- cbslocal.com/2014/09/09/napa-val- Earthquake Engineering Research physical setting of the 2000 ML 5.2 ley-wine-industry-reports-80-3-mil- Center, and U.S. Geological Survey. Yountville, California, earthquake: lion-in-damages-from-earthquake/; Report No. GEER-037, Section 3. Implications for Seismic Hazard in accessed September 23, 2014. http://www.geerassociation.org/ Napa Valley, California.” Bulletin of GEER_Post%20EQ%20Reports/ the Seismological Society of America, CEA, 2014. “CEA policyhold- SouthNapa_2014/GEER_South- 89.pp. 1192-1198. ers already submitting claims for Napa_9-15-2014_reduced.pdf damage to homes from American Lienkaemper, Jim., 2014. Personal Canyon Earthquake,” August 24. Eidinger, J., ed., 2014. ASCE TCLEE communication. U.S. Geological http://www.earthquakeauthor- Preliminary Reconnaissance Report Survey, 9/19/2014 ity.com/UserFiles/File/Release/ of the August 2014 South Napa American%20Canyon%20Earth- Earthquake, American Society of Miranda, E. and H. Aslani, 2000. Brief quake%20Release%20Aug%20 Civil Engineers Technical Council Report on the September 3, 2000 24%202014.pdf; accessed Septem- of Lifeline Earthquake Engineering, Yountville/Napa, California Earth- ber 24, 2014. September 2. http://www.asce.org/ quake. http://peer.berkeley.edu/pub- uploadedFiles/Technical_Groups_ lications/yountville-napa_sep-2000. City of Napa, 2014. “Earthquake and_Institutes/TCLEE/NAPA%20 html; accessed September 28, 2014. Recovery Status Report,” August 2014%20ASCE%20Final.pdf 29. http://www.cityofnapa.org/index. Napa County Red Cross, 2014. In php?option=com_content&view=a EQE CAT, 2014. Strong earth- Facebook [Page]. Retrieved October rticle&id=1864%3Acurrent-status- quake strikes Napa Valley, shakes 17, 2014. https://www.facebook.com/ 1pm-aug-29-2014&catid=1%3Alates San Francisco Bay region. August napacountyredcross t&Itemid=923; accessed September 24.http://www.eqecat.com/catwatch/ 23, 2014. strong-earthquake-strikes-napa- Napa Local Assistance Center, 2014. valley-shakes-sf-bay-region-2014-08- Frequently asked questions. http:// Clahan, K.B., et al, 2004. Geologic 24/;accessed September 23, 2014. www.napaquakeinfo.com/faqs.html; Map of the Napa 7.5’ Quadrangle, accessed September 24, 2014. Napa County, California: A Digital Field, E.H., et al. 2013. Uniform Cali- Database. http://www.conservation. fornia earthquake rupture forecast, Napa Valley Register, 2014. “Red ca.gov/cgs/rghm/rgm/preliminary_ version 3 (UCERF3)—The time- Cross closes overnight post-earth- geologic_maps.html independent model. U.S. Geological quake shelter in Napa,” September 8. Survey Open-File Report 2013–1165., http://napavalleyregister.com/news/ Clahan, K.B., 2011. Paleoearth- California Geological Survey Special local/red-cross-closes-overnight- quake Chronology along the North- Report 228, and Southern California post-earthquake-shelter-in-napa/ ern West Napa Fault Zone, Napa Earthquake Center Publication 1792 article_cbe9127e-1584-5d5d-8464- County, California. U.S. Geological http://pubs.usgs.gov/of/2013/1165/. 91c1feeac2b4.html; accessed Sep- Survey Final Technical Report, NE tember 23, 2014. HRP Award number 07HQGR0081. Fimrite, P., 2014. “Northern Califor- nia earthquake: Blue-collar Vallejo Pender, K., 2014a. “Catastrophe- Clearinghouse, 2014. California hit hard,” San Francisco Chronicle, modeling firms view Northern Califor- Earthquake Virtual Clearinghouse August 25. http://www.sfchronicle. nia quake damage.” San Francisco website, Earthquake Engineer- com/; accessed September 24, 2014. Chronicle, August 27. http://www. ing Research Institute. http://www. sfchronicle.com. eqclearinghouse.org/2014-08-24- Haefner, S. and Blair, L., 2014. Clear- south-napa inghouse Field Notes, United States Pender, K., 2014b. “Insured losses Geological Survey, http://bayquakeal- from Napa quake won’t top $250 Dawson, T., et al., 2014. “Surface liance.org/fieldnotes/ million, RMS says.” Sfgate, Sep- fault rupture associated with the tember 2. http://blog.sfgate.com/ South Napa Earthquake of August Kane, W., 2014. “Sonoma County pender/2014/09/02/insured-losses- 24, 2014,” in Geotechnical Engi- declares quake disaster,” San Fran- from-napa-quake-wont-top-250-mil- neering Reconnaissance of the cisco Chronicle. http://www.sfchron- lion-rms-says/; accessed September August 24, 2014 M6 South Napa icle.com; accessed September 24, 23, 2014. Earthquake. Report of the NSF- 2014.

26 EERI Special Earthquake Report – October 2014

Rasmus, A., 2014. “Napa winer- USGS, 2014a. Updated Finite without-insurance-napa-winemak- ies suffered more than $80 million Fault Results for the Aug 24, 2014 ers-must-absorb-quake-losses- in quake damage,” September 9. Mw 6.0 Earthquake 6 km NW n189401; accessed September http://www.ktvu.com/news/news/ of American Canyon, California 23, 2014. local/napa-wineries-suffered-more- Earthquake (Version 2). http:// 80-million-quake-damag/nhJn4/; earthquake.usgs.gov/earthquakes/ Wyatt, L., 2014. SBA disaster accessed September 25, 2014. eventpage/nc72282711#scientific; assistance available to California accessed September 25, 2014. private, nonprofit organizations. St. John, P. and L.J. Nelson, 2014. Cal OES Newsroom, Septem- “Earthquake damage in Vallejo is USGS, 2014b. M6.0 - 6km NW ber 12. http://caloesnewsroom. put at $5.2 million in early esti- of American Canyon, California wordpress.com/2014/09/12/ mates, Los Angeles Times, August Shakemap. http://earthquake. sba-disaster-assistance-available- 25. http://www.latimes.com. usgs.gov/earthquakes/eventpage/ to-california-private-nonprofit-orga- nc72282711#shakemap; accessed nizations-2/; accessed September Trains, 2014. “Napa earthquake September 25, 2014. 26, 2014. shuts down Wine Train, delays Amtrak movements,” Trains Maga- Wesling, J.R., and K.L. Hanson, Yune, H., 2014a. “Napa shelter zine, August 25. http://trn.trains. 2008. Digital compilation of West tends to earthquake’s hardest-hit,” com/news/news-wire/2014/08/ Napa fault data for the Northern Napa Valley Register, August 25. napa-earthquake-shuts-down- California Quaternary Fault Map http://napavalleyregister.com. wine-train-delays-amtrak-move- Database. Final Technical Report ments. submitted to the U.S. Geological Yune, H., 2014b. “Agencies join Survey, NEHRP Award number forces, open Napa earthquake USA.com, n.d.a. Napa County,. 05HQAG0002. aid center,” Napa Valley Register, http://www.usa.com/napa-county- September 8. http://napavalleyreg- ca.htm; accessed September 21, White, M.C., 2014. Without insur- ister.com. 2014. ance, Napa winemakers must absorb quake losses. NBC News, Yune, H., 2014c. “Napa tallies USA.com, n.d.b. Solano County. August 26. http://www.nbcnews. earthquake damage across city,” http://www.usa.com/solano- com/business/business-news/ Napa Valley Register, September county-ca.htm; accessed Septem- 17. http://napavalleyregister.com. ber 21, 2014.

27