Hollywood fault may lie under some well-known properties

The LA Times has taken the state's preliminary maps of the earthquake faults that pass under Hollywood, released in January, and added an interesting visual. Using Google Earth, Times data and graphics journalists produced a video that flies along the current most-likely path of the fault zone from around Sunset and La Cienega, along the Sunset Strip and the base of the Hollywood Hills, through Los Feliz and into Atwater Village. You see the stripe representing the current (but not necessarily final) thinking on the fault's course passing under Sunset's Mondrian and Standard hotels, the iconic Capitol Records tower and Immaculate Heart High School.

From the accompanying story:

Dealing with the earthquake risk is complicated by uncertainty among scientists about exactly where the faults actually lie.

In some areas, state geologists are fairly certain of fault locations based on such features as the hill St. Stephen's sits upon or sharp changes in the soil, rock and groundwater levels. Along other sections, scientists have estimated the path of faults by connecting points where a fault has been identified through excavation. Also, unidentified fault strands could extend away from the main path.

Seismic experts consider underground studies the best way to determine the path of a fault. But even that may not always be definitive, if, for example, the trench is not dug deep enough....

Mapping active earthquake faults is required under the Alquist-Priolo Earthquake Fault Zoning Act, which generally prohibits building over active faults. The state law passed after the 1971 Sylmar earthquake ripped apart many homes directly on top of the San Fernando fault.

State officials were initially aggressive about mapping faults, but budget cuts stalled efforts over the last 20 years. Of an estimated 7,000 miles of active faults in California, 2,000 still need to be mapped — in places such as L.A. County's Westside, Orange County, Pasadena, Lake Tahoe and the San Diego and San Francisco Bay areas.