UPDATE AND TIMELINE:
On August 14, in a public hearing, the State Mining and Geology Board recommended that the California Geologic Survey consider the data from Group Delta's investigations which found no evidence of active faults at four sites in the vicinity of the Captiol Records building in Hollywood.
Stephen Testa, executive officer of the State Mining and Geology Board, stated that there appears to be "a lot of strong evidence" that an active earthquake fault is not present as indicated by the California Geological Survey's proposed zoning map. "You know what you see" said Testa, "and there was no fault or faulting deposits in those trenches that were observed".
The new investigation reaffirmed the conclusions of the previous investigation that there is no evidence of any active fault at these sites. Based on the comprehensive and exhaustive studies conducted at these sites which yielded no evidence of faulting, the California Geologic Survey is being asked to revise the Hollywood Fault AP Map when it is finalized. (The preliminary map shows the approximate location of an active fault trace running through these properties.)
In May 2014, The Los Angeles Department of Building and Safety Department who have the final say over whether a structure can be built, requested additional studies to be performed to be certain that no active fault existed at the site at 6230 Yucca Street. An active fault is defined as one which has ruptured in the past 11,000 years (Holocene era).
Group Delta worked on fault investigations at multiple sites along the Hollywood Fault. In May 2014, we submitted our report on the first site located at 6230 Yucca Street to the City of Los Angeles for approval. A 16-story apartment building is proposed to be built at this location. At this site, after a 4-month long thorough investigation, no evidence of an active fault was found.
On March 13, 2014 the State Mining and Geology Board conducted a public hearing meeting at which the Preliminary Hollywood Fault Map was discussed. At the meeting the California Geological Survey (CGS) presented some supporting data for the selection of the location of the fault trace shown on the preliminary fault map. Representatives of developers who are currently conducting earthquake fault investigations on their properties in the affected areas in Hollywood requested that the public comment period be extended so as to be able to complete their investigations and present their reports to the Board for their consideration.
In January 2014, the California Geologic Survey released an updated preliminary review map of earthquake fault zones in the Hollywood Quadrangle. The preliminary map shows the Hollywood Fault Zone beginning near the Atwater Village neighborhood in the east, through central Hollywood and ending near La Cienega and Sunset Boulevard in the west. After a 90-day public comment period and review of geological studies which are currently underway, a final version of the map is scheduled to be released later in 2014. [Download the AP map from CGS]
Are you a a Developer or Homeowner impacted by the Preliminary Hollywood Fault Map? If so, turn to the experts at Group Delta. We have the expertise and decades of experience in seismic investigations, working with government regulatory agencies to help you optimize the use of your property.
Call us at (310) 320-5100 and mention hollywood-fault.com for a no-cost/no-obligation site-specific review of your property.
The intent of the Alquist Priolo (AP) Act and related Fault Zone Maps is to prevent the property damage and possible loss of life when structures are built directly on the surface trace of active faults . AP maps show the best known location of the surface trace of a fault at the time the map was published. When the exact location of a fault trace is not known, the AP map shows it's approximate location with dashes, dots, or a question mark where the location is unknown.
It should be noted that the Preliminary Map for the Hollywood Fault identifies Preliminary Zones for Review which will be finalized following a public comment period and incorporation of data gathered from on-going geological studies. If a property is located in an earthquake zone, a geologic fault hazard investigation is necessary before any new construction is permitted to proceed.
The location of the Hollywood fault zone can be visualized in a video which overlays the Preliminary Hollywood Fault Zone on 3D imagery from Google Earth. The video follows the fault zone westward from Western Avenue to La Cienega in Central Hollywood. The fault is believed to extend westward beyond La Cienega and will probably be shown in an upcoming update to the Beverly Hills Quadrangle AP map.
Note: The video is based on documents released by the California Geologic Survey which are preliminary and should be considered approximations only. The local regulatory agency which issues construction permits will make the final determination as to whether a given property falls within an AP Earthquake Fault Zone.
The Los Angeles Times has also published an interactive map tool which allows you to view where a specified address is with respect to the estimated Hollywood Fault Zone.
Group Delta, a geological and geotechnical engineering consulting firm has been serving clients in Southern California for more than 25 years. We have a complete staff of geologists including expert paleoseismologists, who routinely evaluate properties for fault rupture hazards according to the standards mandated by the AP Zoning Act. For more information, or to request a consultation on your project, please visit our web site.