With an area of perceptibility of around 58,500 km2 , the shock was felt from Santa Barbara and Bakersfield to San Diego , Palm Springs , and Las Vegas . This is about half the felt area that was seen during the 1987 Whittier Narrows earthquake , which was felt over an area of 110,000 km2 . The maximum intensity observed in the urban areas that were affected was VII ( '' Very strong '' ) , but the intensity in the epicentral area is unknown because of its remote location in the mountainous Angeles National Forest , though rock slides and landslides occurred there as a result of strong shaking . Intensity VI ( '' Strong '' ) effects were observed over 1,100 km2 , from Altadena and La Verne along the base of the mountains , to East Los Angeles
1987 Whittier Narrows earthquake
1987 Whittier Narrows earthquake
1991 Sierra Madre earthquake