Maps showing areas in Los Angeles and Orange counties where earthquake damage is most likely to be exacerbated by soil liquefaction were released Thursday by the state Department of Conservation.
The 24 maps, which cover about 2,600 square miles in 83 cities, are intended for use when planning new structures or selling existing ones, state geologist James Davis said.
He said developers will be required to conduct special soil tests before undertaking construction in one of the high-risk zones marked on the maps. Sellers of property in such zones will be required to fill out hazard disclosure statements for potential buyers.
The high-risk zones are generally in areas next to waterways. They include property along the Los Angeles River in Sherman Oaks, Encino and downtown Los Angeles and land near Ballona Creek in Playa del Rey and Marina del Rey.
Geologists say liquefaction occurs when an earthquake jars loosely compacted, moist earth, causing the soil to lose its stability, often becoming gelatinous.