Group Delta is currently working on fault investigations at multiple sites along the Hollywood Fault. We recently 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. For the full story and unique photos taken at this fault trench investigation from inside the fence click here.
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]
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.