California geology officials have released an updated seismic map that they hope will improve earthquake preparedness and construction decisions.
The map, which had not been updated since 1994, includes more than 50 new fault lines discovered over the last two decades.
The map was unveiled on Tuesday at The Tech Museum in San Jose as the California Geological Survey celebrated its 150th anniversary. The Geological Survey also presented an updated version of a second map that identifies the makeup of rock and soil.
State geologist John Parrish said the maps can help guide decisions about where to build schools and hospitals and where construction standards need to be higher.
"These maps are used to make a lot of other maps, to map landslides ... for tsunami coastal mapping," Parrish said. "They can tell you what kind of a surface you're building on, and how close you are to a fault."
The more than 50 additional surface fault lines are among an estimated 15,000 faults in the state.
Parrish said residents living near the new lines should not necessarily panic. Many of them are small and aren't expected to generate major earthquakes.
The new maps are more detailed and have interactive digital versions that are linked to Google maps, state officials say.
The seismic map is the fourth to be released by the state.
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