latimesblogs.latimes.com — The earthquake may have measured only a 3.9, but it still could make history in Orange County. Monday's temblor, centered in the southern suburb of Laguna Niguel, could be the first measured on a fault discovered only 13 years ago, which runs along the coast from Newport Beach and Costa Mesa to San Juan Capistrano -- and is close to the San Onofre nuclear power plant.