She noticed a framed photo on his desk. It showed a pretty redhead with a child in her arms. People always liked to talk about their children. “Who’s this?” she said.
“Nobody important. You want to get to the point?”
She took him at his word and asked her question right out. “I need to know if a terrorist group could trigger an earthquake.”
“Have you had a threat?”
He shook his head. “Is it serious?”
“That’s what I need to establish.”
“Okay. Well, the short answer is yes.”
Judy felt a frisson of fear. Quercus seemed so sure. She had been hoping for the opposite answer. She said: “How could they do it?”
“Take a nuclear bomb, put it at the bottom of a deep mine shaft, and detonate it. That’ll do the trick. But you probably want a more realistic scenario.”
“Yeah. Imagine
“Oh, I could do it.”
Judy wondered if he was just bragging. “Explain how.”
“Okay.” He reached down behind his desk and picked up a short plank of wood and a regular house brick. He obviously kept them there for this purpose. He put the plank on his desk and the brick on the plank. Then he lifted one end of the plank slowly until the brick slid down the slope onto the desk. “The brick slips when the gravity pulling it overcomes the friction holding it still,” he said. “Okay so far?”
“Sure.”
“A fault such as the San Andreas is a place where two adjacent slabs of the earth’s crust are moving in different directions. Imagine a pair of icebergs scraping past one another. They don’t move smoothly: they get jammed. Then, when they’re stuck, pressure builds up, slowly but surely, over the decades.”
“So how does that lead to earthquakes?”
“Something happens to release all that stored-up energy.” He lifted one end of the plank again. This time he stopped just before the brick began to slide. “Several sections of the San Andreas fault are like this — just about ready to slip, any decade now. Take this.”
He handed Judy a clear plastic twelve-inch ruler.
“Now tap the plank sharply just in front of the brick.”
She did so, and the brick began to slide.
Quercus grabbed it and stopped it. “When the plank is tilted, it takes only a little tap to make the brick move. And where the San Andreas is under tremendous pressure, a little nudge may be enough to unjam the slabs. Then they slip — and all that pent-up energy shakes the earth.”
Quercus might be abrasive, but once he got onto his subject he was a pleasure to listen to. He was a clear thinker, and he explained himself easily, without condescending. Despite the ominous picture he was painting, Judy realized she was enjoying talking to him, and not just because he was so good-looking. “Is that what happens in most earthquakes?”
“I believe so, though some other seismologists might disagree. There are natural vibrations that resound through the earth’s crust from time to time. Most earthquakes are probably triggered by the right vibration in the right place at the right time.”
“They need a ruler, and they need to know where to tap.”
“What’s the real-life equivalent of the ruler? A nuclear bomb?”
“They don’t need anything so powerful. They have to send a shock wave through the earth’s crust, that’s all. If they know exactly where the fault is vulnerable, they might do it with a charge of dynamite, precisely placed.”
“Anyone can get hold of dynamite if they really want to.”
“The explosion would have to be underground. I guess drilling a shaft would be the challenge for a terrorist group.”
Judy wondered if the blue-collar man imagined by Simon Sparrow was a drilling rig operator. Such men would surely need a special license. A quick check with the Department of Motor Vehicles might yield a list of all of them in California. There could not be many.
Quercus went on: “They would obviously need drilling equipment, expertise, and some kind of pretext to get permission.”
Those problems were not insurmountable. “Is it really so simple?” Judy said.
“Listen, I’m not telling you this would work. I’m saying it might. No one will know for sure until they try it. I can try to give you some insight into how these things happen, but you’ll have to make your own assessment of the risk.”
Judy nodded. She had used almost the same words last night in telling Bo what she needed. Quercus might act like an asshole sometimes, but as Bo would say, everyone needed an asshole now and again. “So knowing where to place the charge is everything?”
“Yes.”
“Who has that information?”
“Universities, the state geologist … me. We all share information.”
“Anyone can get hold of it?”
“It’s not secret, though you would need to have some scientific knowledge to interpret the data.”
“So someone in the terrorist group would have to be a seismologist.”
“Yes. Could be a student.”
Judy thought of the educated thirty-year-old woman who was doing the typing, according to Simon’s theory. She could be a graduate student. How many geology students were there in California? How long would it take to find and interview them all?
Quercus went on: “And there’s one other factor: earth tides. The oceans move this way and that under the gravitational influence of the moon, and the solid earth is subject to the same forces. Twice a day there’s a seismic window, when the fault line is under extra stress because of the tides; and that’s when an earthquake is most likely — or most easy to trigger. Which is my specialty. I’m the only person who has done extensive calculations of seismic windows for California faults.”
“Could someone have gotten this data from you?”
“Well, I’m in the business of selling it.” He gave a rueful smile. “But, as you can see, my business isn’t making me rich. I have one contract, with a big insurance company, and that pays the rent, but unfortunately that’s all. My theories about seismic windows make me kind of a maverick, and corporate America hates mavericks.”
The note of wry self-deprecation was surprising, and Judy started to like him better. “Someone might have taken the information without your knowledge. Have you been burgled lately?”
“Never.”
“Could your data have been copied by a friend or relative?”
“I don’t think so. No one spends time in this room without my being here.”
She picked up the photo from his desk. “Your wife, or girlfriend?”
He looked annoyed and took the picture out of her hand. “I’m separated from my wife, and I don’t have a girlfriend.”
“Is that so?” said Judy. She had got everything she needed from him. She stood up. “I appreciate your time, Professor.”
“Please call me Michael. I’ve enjoyed talking to you.”
She was surprised.
He added: “You pick up fast. That makes it more fun.”
