The City of Los Angeles Department of Building and Safety (LADBS) issued Geology Report Approval Letters for ...
After reviewing geologIcal and seismic data submitted for consideration during the public comment period, the California Geologic Survey released the official map showing the Earthquake Zones of Required Investigation in the Hollywood Quadrangle. The new map format combines Earthquake Fault Zones, Liquefaction Zones, and Earthquake-Induced Landslide Zones.
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 Capitol 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.)
The Los Angeles Department of Building and Safety (LADBS) 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.
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.
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]
1 / 1
U.S. Geological Survey, General Information Product 15, 2005