150 miles into Kentucky.
Atkins and Jacobs were particularly interested in the area in extreme southwestern Kentucky and northwestern Tennessee where that fault intersected with one of the major segments of the New Madrid Seismic Zone. Due west of Kentucky Lake and the town of Mayfield, it was familiar ground for Atkins and Elizabeth Holleran.
A five-member team flew up there—Atkins, Elizabeth, Walt Jacobs, and two of Weston’s geologists—Stan Marshal and Mark Wren.
They’d brought two hundred pounds of water-gel explosives packed in plastic sticks. The electric blasting caps that detonated the charge were connected to a specially designed condenser. The explosion was set off by radio wave, using a 1,000-volt remote-control blasting machine.
They also had half a dozen portable seismographs and geophones, which would record the ground vibrations and convert them into electrical signals that could be captured on magnetic tape. The seismographs would measure the waves as they moved through the deep earth. Faults and other irregularities would cause the signals to slow down or speed up. This so-called “reflection” technique had been used since the 1920s to detect buried oil and gas formations.
The other equipment consisted of two German-made “vibrators,” big gas-powered devices that looked like jackhammers. The machines rapidly pounded a flat metal plate against the ground, producing seismic waves. The seismographs and geophones recorded them.
The idea was to use the varying wave patterns to map out, much like a CAT scan, what the fault looked like and how much fracturing of the rock had taken place. The data would project the fault’s length and breadth and help them determine how much strain energy remained in the ground; heavy fracturing and the degree to which the fractures had opened were dead giveaways that rocks were under severe strain.
The three-man Army crew, all heavily armed, served as a security detail.
When Atkins asked about the need for this, the pilot told them it was too dangerous to travel unarmed. “There’s been a lot of looting,” he said. “It’s going to take a while before we get things under control.”
There were also reports of wild dogs roaming the countryside in packs, he said.
Elizabeth felt a twinge of anxiety, remembering how close she’d come to being mauled in that creek bed near Blytheville, Arkansas. Like Atkins, she wished they had time to investigate whether the animals were reacting to something they detected in the ground. She wondered if the continued aftershocks had anything to do with their behavior.
Or did they sense another big quake was coming?
She put that troubling thought out of mind as the chopper flew right over Kentucky Lake. The water level had dropped a good thirty to forty feet, but water was still rushing through the smashed dam into the swollen Tennessee River.
It was her first good look at the dam since the earthquake. She couldn’t believe how totally it had given away. The huge structure—gates, concrete walls, power station—had vanished. Only the twisted remains of the boat lock remained.
She stared at the gray water, remembering how she’d almost drowned down there. The surface was still choppy with whitecaps. They were flying across the lake from east to west, against a strong wind.
Elizabeth figured something more than the wind was responsible for all that boiling water below them. The turbulence extended as far down the wide lake as she could see.
Atkins knew what she was thinking.
“The ground is still incredibly active,” he said. “The lake hasn’t had time to settle down.”
THE first stop was near Dexter, Kentucky, about forty miles west of the lake. Atkins remembered the countryside well. It was close to the coal mine he and Jacobs had descended to get seismic readings the morning before the earthquake.
How long ago had that been? Three days? Four? He’d lost count.
Working in teams, they operated the vibrators, moving them back and forth over sweep zones a hundred yards wide. They took readings at several sites. It was a cool day with the temperature in the mid-forties, but after ten minutes of trying to hang on to the bulky machines, Atkins and Jacobs were breathing heavily. The instrument packs they carried on their backs felt like they were filled with bricks. It was hard to take the pounding as the flat metal plate at the end of the vibrator, moving in a blur, struck the ground repeatedly. Every muscle began to ache —bones, jaws, teeth.
Elizabeth monitored the seismographs and geophones. The readings were clean and clear. After several hours, they flew to another site closer to the point where the new fault intersected with the old one in the extreme northwestern corner of Tennessee about 120 miles from Memphis.
The procedure was simple and not unduly hazardous. Using a posthole digger, they dug holes six feet deep and placed the sticks of explosive in them. The water-gel charge was as powerful as dynamite but much safer to handle.
The charge was detonated by remote control from a distance of several hundred yards. The explosions, which blasted clumps of dirt and mud a hundred feet into the air, also sent seismic waves radiating deep into the earth just like a miniature earthquake. Traveling tens of miles, these waves were recorded on seismographs placed near the blast site. The array of geophones picked up the sound waves.
They took turns, setting the explosive charges and detonating them. By three in the afternoon the sun was already low in the sky. The pilot was under strict orders from his base commander to be back in Memphis before nightfall. Too many people were shooting at aircraft in the dark. It had become a popular post-earthquake pastime. Several planes had been hit by automatic rifle fire in rural Tennessee and Kentucky.
Before they had to leave, there was time for one more test shot. It was Atkins and Elizabeth’s turn to place the charge. Jacobs helped.
As the helicopter crew watched from the safe distance, Elizabeth lowered the explosive charge gently into the hole they’d dug. She’d already wired the electric blasting cap to the condenser, which was attached to the stick of water-gel. By adjusting a dial, Atkins set the condensing device to receive the radio frequency that would detonate the explosives.
As they started back from the hole, Atkins saw Wren frantically waving at them. About a hundred yards away, he was shouting something and motioning with his hands, holding them palms down.
“Hit the dirt!” Jacobs yelled, instinctively realizing something had gone wrong.
Atkins threw himself into Elizabeth, pushing her down just as the ground erupted behind them. The concussion knocked them breathless. Clods of dirt and mud rained down on them.
Still gasping for air, Atkins staggered to his feet
Wren ran out to meet him. “It was an accident,” he shouted. “Are you all right?”
“What happened?” Atkins said. He was furious.
“Something must have gone wrong with the blasting machine,” Wren said. “The ready-to-fire light blinked on. That’s when I started shouting to you. Then the charge went off. It just happened.”
Just happened?
Atkins didn’t believe it for a minute. The blasting machine wouldn’t send out a radio signal unless the red “fire” switch was deliberately pressed. The machine required a precise series of steps to detonate a charge. First you had to press a green “charge” switch and hold it down until the meter showed the device was fully deflected to 1,000 volts. Then, while continuing to hold down the “charge” switch, you pressed the red “fire” switch. It was definitely a two-hand procedure, not easy to make a mistake.
Atkins shouted for Marshal, who hadn’t moved from his position by the blaster.
“Why did you push the firing switch?” Atkins yelled. “You could see we weren’t clear of the blast site.”
“I didn’t touch it,” Marshal said. “It was your job to set the frequency on the condenser. You must have screwed up.”
Marshal was almost a head taller than Atkins and heavier through the shoulders and chest. Moving straight at him, Atkins ducked under a right upper cut and hit him in the chest. He hit him twice in the face, but Marshal didn’t go down. He fought back, throwing hard punches that Atkins deflected.
Jacobs and the soldiers ran over and separated them.
“You stupid sonofabitch!” Atkins shouted. “You could have killed us.”
Marshal, bleeding from the nose, roughly pulled away from two soldiers who were trying to hold him.
