Apodaca: Expert weighs in after small earthquakes shake things up in O.C.

Many Orange County residents were undoubtedly agitated when the earth rumbled in early June — not once but three times in just a couple of days. Even those of us who grew up in earthquake country might have felt their anxiety levels spike during and immediately after the trio of minor but nerve-rattling temblors.

Not Lisa Grant Ludwig. She was excited. And that’s good news for the rest of us.

Grant Ludwig is a leading expert on earthquakes. She is a Stanford and Caltech-educated geologist, current UC Irvine professor and chair of UCI Public Health’s Department of Population Health and Disease Prevention. Past president of the Seismological Society of America, she has testified before Congress, received a medal from NASA and served on a federal advisory committee dedicated to earthquake safety.

I could go on listing Grant Ludwig’s impressive credentials, but I think the point is clear: She is brilliant, knows as much or more than anyone about earthquakes — particularly those in our backyard — and she had devoted her career to reducing earthquake risks.

So she is exactly the person we want to get excited when we’re hit with a few relatively mild quakes. That ebullience means that she learned something potentially important that could help her and others who are working hard to keep all of us much safer when the ground shakes.

Grant Ludwig was born in Norway, but her family moved to California when she was very young. The 1971 San Fernando earthquake, which toppled the church where she was baptized, made a big impression.

During her school years she was drawn to the earth sciences and what she describes as the interplay between the earth and humans. But it wasn’t until she was in graduate school at Caltech and the Whittier Narrows quake hit that her attention began turning from water pollution to earthquakes. She recalls a particular light-bulb moment inspired by a comment made by one of her professors that earthquakes don’t kill people, buildings do.

“I was just really fascinated by earthquakes,” she said. “It seemed to me a more challenging problem because you can’t ever prevent earthquakes. The solution to the earthquake problem is a human one.”

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Another turning point occurred when she was still in graduate school and the Landers quake occurred. At the time she was in a hospital, about to give birth to her first child, and her critically ill grandmother was in another hospital. After her grandmother passed away, she began pondering the question of how infrastructure impacts public health — thinking that ultimately led her to work in the School of Public Health, an unusual move for a geologist.

“It’s very problem-focused,” she explained. “You can take any disciplinary background and focus it on real-world problems that impact people’s health and well-being.”

Which brings us back to the recent earthquakes, what she learned from them and what can be done to improve safety.

Grant Ludwig was kind enough to dumb down some highly technical information for me. At the most basic, it’s important to understand that there are different types of quakes and faults.

Most of us have probably heard of the Newport-Inglewood Fault, a major fault zone that runs through densely populated coastal communities and is probably a bigger threat to Orange County than even the San Andreas Fault. A destructive 6.4 quake occurred on that fault in 1933 — although it’s known as the Long Beach earthquake, Grant Ludwig said that the epicenter was actually around the Huntington Beach-Newport Beach boundary — and that prompted the adoption of some new regulations.

When the trio of smaller quakes occurred recently, some initial reports suggested the culprit could again have been the Newport-Inglewood Fault. Like the San Andreas, it’s what’s known as a strike-slip fault, which moves predominantly in a horizontal direction.

But under the San Joaquin Hills there’s also a blind thrust fault — that is, it’s underground so we can’t see it, and it moves vertically. It bears some resemblance to the fault that caused the Northridge earthquake, but less is known about it.

The three recent temblors were thrust quakes, and they were all located around where Grant-Ludwig believes the San Joaquin Hills Fault converges with the Newport-Inglewood Fault. What’s more, they were oriented in ways that she had previously expected from the San Joaquin Hills Fault. The data collected could lead to a better understanding of how future earthquakes might behave and what areas are most vulnerable.

Such knowledge also informs another critical component of Grant Ludwig’s work — policy.

On that front, she is advocating for reauthorization of the 1970s-era National Earthquake Hazard Reduction Program, which supports research, strategies, tools and techniques to reduce the adverse effects of earthquakes, yet is in danger of seeing its funding lapse.

She also wants more advanced early-warning systems, and a comprehensive plan to ensure that all structures are earthquake-resistant and held to standards that could be adjusted based on an area’s seismic risk. She even has a novel idea for posting earthquake safety ratings on every building, similar to the grading system used for restaurants.

Now she’s preparing to take a sabbatical to undertake another worthy endeavor — writing a book that will sketch out her recommendations.

So yes, I think we can excuse Grant Ludwig if she gets a little giddy about earthquakes. It means she’s putting her considerable brainpower to work on solutions that will benefit all of us.