Glendale (PDF) - Hazard Mitigation Web Portal - State of California

Natural Hazards Mitigation PlanCity of Glendale, CaliforniaSection 6 – Earthquakesrisks including active fault identification, ground shaking, ground motion amplification, liquefaction,earthquake induced landslides, and for coastal areas, tsunami inundation zones. Seismic hazard mapshave been published and are available for many communities in California through the CaliforniaGeological Survey. Some of the most significant earthquake-induced hazards with the potential toimpact the city of Glendale are described below.Seismic ShakingSeismic shaking is the seismic hazard that has the greatest potential to severely impact Glendalegiven the city’s proximity to several active seismic sources (faults). To give the City a betterunderstanding of the hazard posed by these faults, we performed a deterministic seismic hazardanalysis to estimate the Peak Horizontal Ground Accelerations (PHGA) that can be expected atGlendale’s City Center due to earthquakes occurring on any of the known active or potentially activefaults within 100 km (62 miles) from the city. We also conducted probabilistic seismic hazardanalyses to estimate the median PHGA at twelve different sites throughout the city. Those faultsthat, based on the ground shaking analyses described above, can cause peak horizontal groundaccelerations of about 0.1g or greater (Modified Mercalli Intensities greater than VII) in theGlendale area are listed in Table 6-3. For a map showing most of these faults, refer to Map 6-1.Those faults included in Table 6-3 that pose the greatest impact on the Glendale area, or that arethought to have a higher probability of causing an earthquake, are described in more detail in thefollowing pages.Table 6-3 shows:• The closest approximate distance, in miles and kilometers, between Glendale’s City Hall andeach of the main faults considered in the deterministic and probabilistic analyses;• the maximum magnitude earthquake (M max ) each fault is estimated capable of generating;• the intensity of ground motion, expressed as a fraction of the acceleration of gravity (g), thatcould be experienced in the Glendale area if the M max occurs on one of these faults; and• the Modified Mercalli seismic Intensity (MMI) values estimated to be felt in the City as aresult of the M max on each one of these faults.2006 PAGE 6 - 15