by Peter Hernon
“The first event, the one of December 16, 1811, was conservatively estimated to be in the magnitude 8.1 to 8.3 range,” Jacobs said. As soon as he began to talk, the fatigue seemed to fall off him. He was animated, well spoken. “We’ve estimated that single quake and related aftershocks released only half of the strain energy stored in the fault zone. Only half, ladies and gentlemen.”
Elizabeth whispered to Atkins, “I don’t know if I want to hear the rest of this.”
“Then the second big quake hit on January 23, 1812,” Jacobs continued. “Research indicates it was another magnitude 8-plus event. Like the first one, the shock waves were felt from the Rockies to the East Coast. We believe it released about sixteen percent of the available strain energy.”
So there was still a ton left in the ground, Atkins thought. It was almost unbelievable.
“Again, there was another flurry of severe aftershocks,” Jacobs said. “Then another big one hit. The last in the sequence. It struck at 3:45 on the morning of February 7. A dip slip rupture that radiated over the entire Reelfoot Rift. It’s been variously estimated as high as a magnitude 8.6 and as low as an 8.1.”
Jacobs looked out at the assembled faces. They were hanging on his every word. “The only point I’m trying to make is that plenty of seismic energy remained locked in the ground after the first quake in the sequence.”
Weston stood, shaking his head. “That’s very interesting, Walt. But the fact that we’ve got a lot of elastic strain energy stored in the ground isn’t proof we’re going to have another magnitude 8 earthquake. And that’s what you’re suggesting. Statistically, it’s a virtual impossibility. For all we know, there are structural barriers that will halt the progression no matter how much strain energy remains. There are too many variables. Too many unknowns. I’m not going to approve any public statement to the contrary.”
“You don’t think we should even warn people of the possibility of another major earthquake?” Atkins asked. They’d had this argument a few days earlier, without result.
“That wouldn’t be responsible,” Weston said. He wasn’t alone in his opinion. Other seismologists, including several prominent members of the USGS, supported him loudly. The atmosphere was tense as Weston argued for restraint.
“But Goddammit, you’re not answering the question. Give me a yes or no answer here, Paul.”
Steve Draper, who’d sat in the back of the room, taking copious notes, suggested they temporarily adjourn the meeting.
“Why don’t we all get something to eat. Try to rest, then get back here in, say, one hour. We’ll go over the numbers again. And our options—if we have any. The president’s eager to get your thinking on further seismic activity.” He studiously avoided the word “prediction.”
Draper took Atkins and Elizabeth aside. “I’d like you to meet someone. He’s got some thoughts on the situation. You might find them provocative.”
He led them to a small conference room in the back of the building. “Atkins, Elizabeth, this is Fred Booker,” Draper said.
NEAR KENTUCKY LAKE
JANUARY 15
5:10 P.M.
LAUREN MITCHELL WAS WORRIED. HER GRANDSON had been gone nearly five hours. He’d left with the shotgun to go hunting. They needed meat, and the boy was a good shot. He’d often killed rabbits and squirrels for the table. The year before, he’d shot his first deer, a two-point buck.
Lauren had made him promise to stay away from any roads. If he heard any cars or trucks coming, she told him to take cover. The roads weren’t safe. Too many bushwhackers were traveling the countryside. In the quake zone, law enforcement had become largely a personal matter. Residents had been urged to do whatever they thought necessary to protect themselves and their property.
Almost as troubling were the reports of unusual animal behavior—stories about wild dogs, cattle, and horses that had gone out of their heads. Lauren still remembered her great-grandfather telling her about the New Madrid quake of 1895. How two days before it hit, all the chickens and dairy cattle on their farm had become frantic. A big Rhode Island red that had never shown any hostility had suddenly attacked him in the hen shed, slashing him with a talon. She remembered how he’d rolled up his shirtsleeve to show her the white scar that ran from his elbow to his wrist.
Lauren thought about that story and about what could happen to Bobby. She was angry with herself for letting him go out alone. They had enough food to last for several more weeks. She never should have let him talk her into going hunting by himself.
She was getting ready to put on a coat and go looking for him when she heard him shouting.
He was running through corn stubble in the field behind their house. He was panting, his breath forming white clouds as he jogged up a low hill. Three large rabbits dangled from his belt. He wore a blue stocking cap and carried the .410 shotgun.
When she stepped out on the back porch, he waved and shouted: “It’s like… a… canyon!”
Struggling to get the words out, he doubled over at the waist and tried to fill his lungs. He dropped his shotgun and the rabbits.
“It’s down by Millet Creek,” he said, still gasping for air.
“What’s down at the creek?” Lauren asked. He’d gone farther than she’d thought. The creek was almost five miles away. It meandered on a crooked line into Clark’s River, which emptied into the Tennessee near Paducah.
“A deep crack in the ground,” Bobby said. “It must have opened up in the quake. You’ve got to come look. It must be a mile long. I couldn’t see the bottom.”
MEMPHIS
JANUARY 1612:15 A.M.
WALT JACOBS SAT BACK IN HIS CHAIR, EYES FIXED straight ahead and shook his head.
“I don’t want to hear any more of this,” he said. “It’s lunacy.”
Steve Draper had asked him to join Atkins and Elizabeth Holleran in an equipment room for a private conversation. It was hard enough for him to focus: he was still waiting for word on his wife and daughter. The two graduate students who’d volunteered to go to his home hadn’t returned, and he was very worried about them as well as about his family. He’d been sleeping less than four hours a day, and his jittery nerves were ready to snap. He had no patience for crazy ideas.
Jacobs rarely lost his temper, but he was as angry as Atkins had ever seen him.
They’d just listened to Fred Booker explain his theory about using a nuclear charge to defuse the earthquake sequence.
Booker was hardly aware of Jacobs’ increasing hostility. Deep in thought, he was standing at a blackboard, using a piece of broken chalk to sketch the fault zone Guy Thompson had displayed graphically. He was working rapidly, making quick, sharp strokes on the board. Chalk fragments were flying.
“If this is the most seismically active segment, I’d make it my target.” He circled the area then drew a horizontal line right through it. “That’s where I’d sink the shaft. We put the bomb down as deep as we can go. As deep as we have time for. The size and location, of course, would all have to be precisely calculated. I’d let you people—”
Jacobs had had enough. “We’re in the middle of a catastrophe, and you’re wasting our time with this,” he said, knocking over a chair as he stood up. “We are not going to set off a nuclear explosion. It’s not even worth discussing.”
Atkins said, “How would we know a nuclear charge wouldn’t actually precipitate another big quake? Push it over the edge.” That was the very thing they wanted to avoid and to his way of thinking was the most dangerous element of Booker’s startling proposal. They had absolutely no empirical evidence to fall back on. The thing had never been done. He couldn’t buy this at all.
Booker said, “I can’t answer that. There’s going to be a risk. And I don’t underestimate that. All I’m saying is that if you people can tell me how much energy needs to be released along the fault to reduce the strain energy, I can design and fire a charge that might do the job.” He looked at Jacobs. “Throwing chairs around isn’t going
to solve our problem. It never did out at the Nevada Test Site.”
“To hell with you,” Jacobs said. “So you know how to blow big holes in the ground. Goddammit, what’s the point?”
Booker stood right in front of Jacobs and stared at him. “The point is we can do something,” he said in a loud, frustrated voice. “We can try to do something. We don’t have to sit here and look at our precious data and get clobbered again.” Booker took off his goggles and threw them across the room.
Draper ordered Jacobs and Booker to cool off.
There had long been speculation that a nuclear blast, properly located, might be able to defuse an earthquake. Atkins was aware of it, but that’s all it was. Speculation. No reputable geologist had ever seriously suggested such a thing beyond raising it as a hypothetical. It was a fringe issue—too far-out to be seriously debated, too far-fetched. On the other hand, no one doubted a nuclear bomb could trigger an earthquake. There’d been too many examples. Some of the quakes had been fairly substantial, in the magnitude 5 range, perhaps even a little larger.
Elizabeth said, “Wasn’t there discussion that a Soviet underground test may have set off a mag 7 quake in Iran back in the late seventies?”
“I’m familiar with that earthquake,” Atkins said. He’d visited Tabas, a city in remote western Iran, where at least 25,000 people had been killed. “The Soviets had set off a 10-megaton blast at Semipalitinsk about thirty-six hours before the quake. But no one has ever established a definitive cause-and-effect link between the two events. And that’s the problem with all the antibomb people who worry that underground tests have made the earth more vulnerable to major earthquakes. There’s no hard evidence. It’s an emotional argument without any scientific basis in fact.”
“There are maybe a couple million people living within a three-or four-hour drive of any place you’d put a bomb along that fault,” Jacobs said in a voice that had lost none of its anger. “What happens if something goes wrong and all that radioactivity is vented into the air or leaches into the ground?” He was furious and was making no effort to conceal how he felt.
Booker said, “I’m reasonably sure we can prevent any venting and that if we—”
“Reasonably?” Jacobs sneered, interrupting him.
“Exposing a lot of people to radioactivity is an issue,” Booker said angrily. “No doubt about it. But an equally important question you have to answer is what happens if you get another magnitude 8 quake? What if it triggers seismic activity on those other faults Doctor Thompson was talking about a few minutes ago?” He was as mad as he’d ever been in his life. He’d dealt with stubborn fools all his life. Stubborn fools with Ph.D.’s. He stormed over to where Jacobs was sitting and slammed his fist on the table. “If you think that’s a serious possibility, my question to you is this: Do you try to come up with a way to stop it, or do you just shrug and say, sorry, there’s nothing we can do. It’s an act of nature.”
Booker turned to Atkins, who stood with his back to him, staring holes in the blackboard. “What if you get another triple here? Isn’t that what’s got everyone worried? It’s sure as hell got me worried. I wouldn’t want to see another mag 8 earthquake rip through the valley. It couldn’t survive it, and I’m not sure the country could.”
“We still don’t know how much energy is locked down there,” Atkins said. “There aren’t any adequate ways to measure it.”
“Excuse me, excuse me,” Booker said, clenching his fists and lowering his head in frustration. “But didn’t I just hear a discussion of multiple fractures along that new fault. Isn’t that evidence of elastic strain energy?”
“Yes, but the problem’s always been trying to measure it,” Jacobs said, his hostility unabated. “All we can say for certain is that deformations, or uplift, or the number of aftershocks can indicate a serious buildup of tectonic stress. But we don’t know how much stress has actually loaded up there, or how much it would take to trigger an earthquake.”
Booker took a deep breath. He wondered if the man was even listening to him. “Let me put it as simply as I can,” he said. “Do you think there’s going to be another big earthquake? That’s the question, isn’t it? Is another big earthquake possible?”
For a long time, no one spoke. Then Jacobs said, “Yes, it’s possible.”
NEAR BENTON, KENTUCKY
JANUARY 16
8:00 A.M.
THE NEWS ABOUT THE DEEP FISSURE CAME FROM Lauren Mitchell, who’d managed to find a Red Cross unit near Mayfield with a shortwave radio. Shortly after first light, a team from the earthquake center in Memphis flew directly to the site aboard an Army UH-60 helicopter.
Elizabeth Holleran had never seen anything like it: a fissure running nearly a mile long at depths varying from two hundred to six hundred feet. The deep tear in the ground had been much larger at one point. Visible from the air, the scar that marked where it had already closed extended nearly two miles through the hilly, forested west Kentucky countryside.
It was just after eight in the morning. Powerful spotlights hooked to portable generators illuminated the depths of the crevasse. After spending an hour inspecting it and helping to set up the lights, Elizabeth was ready to make a descent.
Atkins took her aside. “You’re sure about this?” he asked. He didn’t like anything about the plan, but he realized there was no stopping her. The fissure provided an unprecedented opportunity to look for evidence of previous earthquakes. Elizabeth was determined to make the most of it.
“I couldn’t get a trench this good in California if I had a dozen backhoes working overtime for a decade,” she said. She’d spent three years digging two trenches on the San Andreas that were ten feet deep and barely fifty yards long. They didn’t compare.
Elizabeth, Atkins, and a small team from the earthquake center had made the hurried trip to Millet Creek. Paul Weston had wanted to send along Stan Marshal, but had to back off when Atkins and Elizabeth refused to go if he was in the party. Weston chose not to force the issue, realizing he didn’t have a choice. They needed Elizabeth because of her expertise.
The accident with the explosive charge still nagged at Atkins. He wanted to believe it was an accident and yet it bothered him. A man with Marshal’s background and field expertise didn’t make a nearly lethal mistake like that. It just didn’t happen. He needed to think it through. So far he had only a troubling suspicion and enough lingering anger to keep Marshal as far away from him as possible.
He’d hoped Walt Jacobs would make the trip, but Jacobs had been unusually subdued since their conversation with Draper and Booker. Jacobs had begged off looking at the crevasse, saying he needed to stay at the earthquake center.
Atkins guessed there was more to it than his friend’s negative reaction to Booker’s provocative suggestion about using a nuclear explosion. Atkins wasn’t ready to take the idea seriously either. It worried him that an eminent scientist like Steve Draper seemed so interested. After the meeting with Booker, Draper had peppered all of them with pointed, often unanswerable questions. Jacobs had looked distracted, even uninterested, which wasn’t like him. Atkins figured it had to do with his wife and daughter. He still hadn’t had any word on their safety.
Elizabeth wore coveralls, leather gloves, and a hard hat equipped with a powerful spotlight. She also carried a small 35-mm camera from a strap around her neck. They were going to lower her by rope into the fissure, using the helicopter’s electric-powered hoist and air rescue seat.
Atkins didn’t want her to be down there any longer than necessary. Several mild tremors had shaken the region since their arrival and parts of the trench were showing signs of collapse. Pieces of the edge kept breaking away and falling into the chasm.
Atkins had wanted to make the descent with her, but knew he’d only get in the way.
Elizabeth planned to descend as far as possible, looking for evidence of sand blows or offsets, thin cracks in the soil, some of them no more visible than a hairline fracture. Buried in the
various strata, they were telltale signs of earthquakes and her trained eye, sharpened by years of trenching in the San Andreas fault, was expert at picking them out. The recent earthquake had laid them all bare, creating a mural of the past.
She’d look for bits of carbon—fragments of leaves, peat, or twigs deposited in the soil about the time the offset or sand blows had occurred.
By radiocarbon dating these fragments, she could develop a stratigraphic map of the history of the fault’s previous earthquakes. Another Army helicopter—it was already heading their way—would take the samples to the University of Illinois at Champaign-Urbana where they could be carbon-dated. It was the closest accelerator mass spectrometer, a device that could get precise dates from even minute bits of carbon and, in so doing, date the earthquake that had produced the offsets, sand blows, and other formations Elizabeth might find.
Elizabeth didn’t need much carbon, just a few grains. The technology was based on burning the fragments and converting them to carbon dioxide. The carbon dioxide was then heated and converted to graphite. The graphite was inserted into the spectrometer, which could analyze the carbon-14 atoms in the sample and determine its age, give or take thirty years.
“I know it’s your call, but I’d recommend against this,” the crew chief said as he expertly looped a rope under Elizabeth’s arms and fashioned a bowline knot that wouldn’t slip. “This ground’s jumping. This trench could slam shut any time now.”
Atkins couldn’t have agreed more. The recent tremors had been unusually sharp. “Try to make it quick, Liz,” he said. He took her hands in his. This was a fine, brave woman. During the last few days, he’d come to realize how extraordinary she was and how much she meant to him. He wanted to talk to her. They hadn’t had many chances since the quake. Atkins sensed she felt the same way but wasn’t sure. He hoped so at least.