January 16, 2014

Two decades since L.A.’s Northridge earthquake

Posted by Austin Elliott

It’s already been twenty years since Los Angeles was last really rocked by an earthquake. The 4:31am Northridge temblor, a magnitude 6.7 that literally threw the city from its sleep, was the iconic natural disaster of the 1990s and the last in a string of quakes, fires, and mudslides to pummel Los Angeles in the early half of the decade.

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Though violent, destructive, and memorable, the Northridge quake struck merely a glancing blow to Los Angeles. The epicenter was deep beneath the eponymous San Fernando Valley suburbs of Northridge and Reseda, and the deeply buried, south-dipping thrust fault that slipped sent most of the seismic energy rippling northward into Santa Clarita and the surrounding mountains. The dense populations and economic centers to the south, in downtown and the westside, were shaken hard, but not devastatingly.

Nonetheless, collapsed freeways, apartment complexes, and warehouse stores, exploded gas mains and burning neighborhoods, and relentless aftershocks terrorized and cost the city dearly. News footage compiled from the morning of the quake allows you to relive the fearful hours as Angelenos struggled to figure out what happened and assess the toll in the dark.

Despite violent shaking and a messy array of damage, the low casualty toll meant that most Southern Californians counted themselves as survivors and they quickly took to lampooning their tough luck with nature’s onslaught.

They also took stock of lessons learned–each time a big earthquake hits an urban center it counts as a powerful test of existing building codes and infrastructure. Structural and infrastructural failures were tallied and analyzed, and the building code updated… to await the next big test. An article by Caltech’s Tom Heaton paints a sort of dismal picture of what minimal progress has been made since Northridge in preparing for the next Big One, which has a great chance of being bigger and badder than the suburban 1994 temblor.

A recent awareness crusade by the L.A. Times may have rekindled the spirit of earthquake preparation and mitigation in the city, but it takes the whole populace to maintain momentum. Thankfully action is currently being taken at higher echelons of local government to restart improvement of the city’s resilience. The Earthquake Country Alliance has compiled media and information so that you may take this 20-year anniversary as an opportunity to reflect, remember, and put yourself in the place of the hapless Angelenos of 1994, waking up in the pitch black having been thrown from their beds by a shocking but not unexpected surprise. Learn about quakes, about their risk to you, and about how to deal with it.

Fantastic local radio station KPCC has also assembled an elegant array of features commemorating the disaster, including dedicated programming throughout the week, all of which is worth listening to. Their online coverage includes an interactive gallery of then-and-now photos of the destruction and recovery, as well as a map of earthquakes and faults. Contributing reporters wrote a number of articles on quake safety and retrofitting, and they’ve thrown in a worthy dash of editorializing about the nature of living in the quake-beleaguered paradise of L.A.

There are also a few live events to commemorate the anniversary, and there are plenty of lasting resources assembled by the USGS, SCEC, and the joint Earthquake Country Alliance. Welcome to earthquake country. Don’t forget where you live.