What is worse than the “big one”?
The Whittier Narrows California earthquake sequence (local magnitude, Ml=5.9 or 1 October, 1987), which caused over $358 million damage, indicates that assessments of earthquake hazards in Los Angeles metropolitan area may be underestimated. the sequence ruptured a previously unidentified thrust fault that may be part of a large system of thrust faults that extends across the entire east-west length of the northern margin of the Los Angeles basin. Peak horizontal accelerations from the main shock, which were measured at ground level and in structures, were as high as 0.6g (where g is acceleration of gravity at sea level) within 50 kilometers of the epicenter
The first thought in the minds of many residents of the city of Whittier when the first shock hit them was "Is this the big one?" the San Andreas' once-in-150-years great shaker? It might as well have been for Whittier, which is 20 kilometers east of downtown Los Angeles. The ground shook harder there this month than it will when the big one does strike the distant San Andreas, which lies 50 kilometers on the other side of the mountains. And this was only a moderate, magnitude 6.1 shock. Earthquake of magnitude 7 and large 30 times more powerful, could rupture faults beneath the feet of Angelenos at any time. The loss of life and destruction could exceed that caused by the big one.
Additional publication details
|Publication Subtype||Journal Article|
|Title||What is worse than the “big one”?|
|Series title||Earthquakes & Volcanoes (USGS)|
|Publisher||U.S Geological Survey|
|Online Only (Y/N)||N|
|Additional Online Files (Y/N)||N|
|Google Analytic Metrics||Metrics page|