In California, preliminary maps released by the California Geological Survey in January show major developments planned in the Los Angeles areas of Hollywood and West Hollywood close to a newly mapped fault zone.
These maps haven't had any effect on Los Angeles-area earthquake insurance pricing, said Alexandra Glickman, area vice chairman and real estate and hospitality practice leader at Arthur J. Gallagher Risk Management Services Inc. in Glendale, California.
“Overall the earthquake (coverage) capacity and pricing is very competitive and we're seeing a lot more capacity at a lot lower pricing,” she said.
The Hollywood fault runs beneath more than 1,500 already developed properties, including schools, hotels and homes, according to a Los Angeles Times analysis of the preliminary maps, which are expected to be finalized this summer.
The maps identify areas of potential surface fault rupture, said Tim McCrink, supervising engineering geologist at the California Geological Survey in Sacramento. “In the case of fault rupture, right now the only mitigation is to stay off the fault trace,” he said.
“When we heard about those proposed developments, we realized that the city did not have any of our fault maps. They had their own, which were unfortunately out of date,” Mr. McCrink said. “The developers are going ahead with their fault investigations now to see if they have to reconfigure those structures.”
“The building codes are really good and the shaking side is understood,” he said. “But the building codes don't cover ground failure. If you've got a San Andreas fault that you know moves 20 to 30 feet every time it ruptures, you don't want to build on that.”
California's Alquist-Priolo Earthquake Fault Zoning Act — passed after the 1971 Sylmar earthquake along the San Fernando fault — requires fault mapping and generally prohibits construction directly above active faults, said Luke Zamperini, chief inspector of the Los Angeles Department of Building and Safety.
“Once (the maps) become official, then any development that's going on inside this zone will have to have an earthquake fault and rupture study completed before getting permission to build,” he said.