Victor Vescu - How Faults Annoy Their Neighbors

Added: 2026-05-15

[00:00:05]Did anyone feel the earthquake two Mondays ago last August? Maybe you remember rich crest risk crest six years ago. A little scary, right? But we've all lived here long enough to get used to earthquakes. We assume they'll hit where they've hit before and be about the same size. Hold that thought. Now jump to Japan 2011. A magnitude 9 earthquake shakes Tokyo for six minutes.

[00:00:30]Can you imagine two of these talks back to back? Scientists are stunned. The quake came from a fault. Fing capable of something so massive. How? Back to California, we have the San Andreas fault. It's more famous than Schroinger's cat, but less famous than Einstein's hair. The north and south segments, those in red, repeatedly produce large earthquakes. We've tracked them since the 1890s, a blink in geological time. But between them lies the central San Andreas, seemingly tame.

[00:01:04]In recorded history, nothing stronger than a magnitude 6. But the rocks say otherwise. Magnitude 7s did happen there long ago. So what's going on? That's what I study. Dynamic weakening. When faults suddenly give way more easily once they start to sleep. It's how small earthquakes grow large. And faults I found are a lot like people under pressure, stressed, overheated, or when their neighbors get too close, they snap. When fluids get pressurized, sliding forces ramp up, or friction heats things up, even stable faults can fail. Here's the deal. When shaking on a red neighbor happens, it can irritate its green neighbor, thus allowing dynamic weakening. It's kind of like when your neighbor starts mowing the lawn at 6:02 a.m. on a Saturday. You weren't planning to snap, but here we are. I run earthquake simulations on supercomputers to see when one fault segment could trigger another.

[00:02:10]And my goal is to see whether dynamic weakening could trigger a mega quake in California's central region. And so far, under perfect conditions, yes, it's possible. But nature is messy. That's why I love adding physical realism to my models to see when dynamic weakening can and can't happen. Thousands of simulated earthquakes told us that if the sleeping interface is weaker than a deck of cards, dynamic weakening won't happen.

[00:02:37]Small details can flip seismic out seismic outcomes. And that matters because knowing which faults weaken could mean the difference between expecting a magnitude six and getting blindsided by a 7.7. So, are we safe because it hasn't happened in recorded history? My research says maybe not. Give me your zip code and I'll check with the fault.

[00:03:03][Applause]