Shaken, Not Stirred: Northridge Earthquake 20 Years Later
By Maureen Brogan
Published Jan 9, 2014 8:00 AM
UCLA's response has set a new bar for seismic research.
Earthquakes are a fact of life in Southern California. But the 6.7-magnitude temblor that shook the ground at 4:31 a.m. on January 17, 1994, became the largest natural disaster in the history of the United States at the time, causing an estimated 57 fatalities, 12,000 injuries and $40 billion in damage, according to the Public Policy Institute of California.
On the UCLA campus, 17 miles from the epicenter of the Northridge quake, damage was extensive, but the university’s response set a new bar for earthquake research.
In particular, Royce Hall suffered structural impairment to its trademark towers; the 30-ton spires atop Kerckhoff Hall shifted six inches and had to be temporarily removed; and more than 1 million books tumbled from library shelves. But damage to the residence halls was minimal—partly because of a campuswide seismic safety program the university began implementing in the mid-1980s.
The UCLA Medical Center suffered the most extensive structural damage, with the Federal Emergency Management Agency (FEMA) ultimately providing $432 million toward the construction of a replacement hospital. The Ronald Reagan UCLA Medical Center, which opened in 2008, is designed to withstand an 8.0 magnitude earthquake and remain fully operational for those first, crucial 72 hours in the event of a cataclysmic quake.
Jonathan Stewart, current chair of the UCLA civil and environmental engineering department, was a UC Berkeley grad student in 1994 and immediately made his way to the Los Angeles area to help inspect the damage. For the next several weeks, he and three dozen other researchers pored over the “field laboratory” that was Los Angeles, collecting data from earthquake sensors and looking for patterns in the structural damage wrought by the quake.
The team produced a reconnaissance report on the temblor’s impact that was published by the UC Berkeley Earthquake Engineering Research Center, with Stewart as the lead author. “Because of the volume and depth of the Northridge research, we’ve been able to translate our understanding of where and how ground failure occurred into better engineering designs and standards,” Stewart says.
UCLA's Northridge Response
In the two decades since Northridge, UCLA’s earthquake engineering research has been thriving. Faculty, post-doctoral scholars and graduate students research everything from ground motion characterization and seismic ground failure, to how different types of soils and structures respond to seismic shaking, to the engineering and structural dynamics of bridges. In Professor John Wallace’s Structural Testing Laboratory in the basement of Boelter Hall, reinforced concrete walls are built, then shaken with actuators that can simulate varying earthquake magnitudes in order to monitor the walls’ structural integrity.
In addition to creating tools that can predict the effects of seismic activity, UCLA earthquake engineers also travel to sites of major quakes all over the world, both to bring back valuable information and to assist governments in crafting new guidelines in earthquake engineering. As Stewart puts it, “One of our goals is to continue to turn our evolving knowledge of quakes into improved public safety.”