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.
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.
[youtube=http://www.youtube.com/watch?v=Zfuz5WKR5So]
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.
Thanks for the sharing, the article by Tom Heaton really highlights the problems of pre-1975 concrete beam structures and pre-1994 steel structure brittle welding techniques. Also the quote, “..very few of the fragile frame buildings have been retrofitted” doesn’t quite sounds very nice. Basically the article makes you feel that if your in a wooden structure your probably safe but if its concrete or steel, make sure its a modern one. Reading this article reminds me of one the nice quotes from Professor Seed at Berkeley, “Why would anyone want to be an earthquake engineer? If you tell an owner his building is not safe you will get sued for lowing the property value, and if don’t you will get sued after the earthquake because of the collapse”. Fundamentally I think our failure to prepare for earthquakes is not because of the engineering or science community but rather because of a failure in our economic and political climate to allow these changes. But most likely the changes will happen, but the rate of change will be about as quick as congress is at passing meaningful laws.
Exactly right. In the case of risks that are so abstract and remote to the populace, government intervention is extremely important to set standards and regulations that dictate certain precautions and protections for the retrofitting and the occupation of outdated buildings. It looks like both of CA’s big cities are taking important strides, which is understandably daunting given their severely outdated building stocks, combined with their deeply rooted populations.
[…] Francisco, and most recently Los Angeles. Each of these cities was recently dealt a near-miss with a violent earthquake, but that luck won’t last forever. It takes great collective […]