Boyd Morrison - The Tsunami Countdown

“I’m getting the DART buoy data now.”

Kai bent over Reggie’s terminal, explaining to Brad what they were looking at.

“This graph shows the displacement of the height of the sea level as a function of time. As the line of the graph goes up, the height of the sea level increases.”

“How can the buoy detect a change in sea level with all the regular waves going by?”

“The buoy is just a transmitting device. The scientific instrumentation is actually on the ocean floor, measuring changes in pressure of the water above it. Then it sends those readings by an acoustic modem to the buoy, where it links with a communications satellite. The wind-driven waves aren’t big enough to affect the pressure sensor on the seafloor, so it normally only fluctuates with the tidal pull of the moon.”

Kai pointed to an historical graph that showed the sea level height going up and down on a daily basis. “But if a tsunami passes over it, the entire column of water from the surface all the way down to the bottom is affected by the wave.”

“Will you look at that,” Reggie said, his voice weighted with awe.

The line on the graph had already started to climb. Kai held his breath, hoping it would stay small, nothing more than a blip. But the line inexorably rose higher, propelled by the five-hundred-mile-an-hour wave. In two minutes, the line had topped out at 0.65 meters above sea level.

“I guess we’re sure now,” Reggie said.

“Zero point six five meters?” Brad said. “But that’s great! Less than three feet!” His enthusiasm waned when he saw Reggie’s grim face.

Reggie shook his head. “That’s in the open ocean. In a boat, you wouldn’t even notice the change in sea level.”

Kai leaned back, finally coming to grips with the reality of the situation. “In the deep ocean,” he said, “the wave goes all the way to the seafloor. Once it reaches shallow water, it’ll start to bunch up, slow down, and grow in height. How high it gets on land depends on the run-up factor at that part of the coast. Multiply the run-up factor by the wave height at sea, and you get how high the wave will be on land.”

“The run-up factor for Honolulu is forty,” said Reggie.

Brad did a quick mental calculation. “That’s twenty-five meters. Seventy-five feet. At least it’s smaller than two hundred feet.”

Kai shook his head. “A seventy-five-foot wave is huge. Besides, that’s just the first wave. There might be more—maybe two or three more.”

“The computer models from the lab at Los Alamos expected the first wave from an asteroid impact to be the biggest one,” Reggie said. “But this has never happened before, so who knows? We’ll know if and when we get the next DART reading. In any case, we have confirmation now, even without the NASA photos.”

Kai nodded. “Brad, call Brian Renfro back and conference him in with Harry, George, and Mary.”

After a few seconds, they were all on the line, with one added person Kai hadn’t been expecting.

“Kai,” Brian said, “when you first told me your theory, I took the precaution of asking the governor to make her way to the HSCD bunker. She’s still on her way, so I asked her to conference in from her car.”

The governor didn’t waste time with chitchat.

“Dr. Tanaka,” the governor said, “is this a false alarm?”

“I’m sorry to say it isn’t, Governor,” Kai said. “We don’t have much time. I got you all on the line so I would only have to say this once. We believe an asteroid struck the central Pacific about an hour ago, although we don’t have confirmation from NASA just yet. What we do know is that a major tsunami is headed our way. And when I say major , I mean one that will make the Asian tsunami look like a kiddie pool. The first wave will be over twenty meters. If we get more waves, the max wave height could be over seventy meters, but we won’t know for sure until we get the DART buoy readings for any follow-up waves.”

“But you’re sure about the first wave, Dr. Tanaka?” the governor said.

“Yes, Ma’am. No doubt.”

“Okay. Good work catching this in time. Brian tells me that was a gutsy call.”

“Thank you, Ma’am, but we’ve still got a lot of work to do.”

“I know. I’m getting off the phone now so I can mobilize the National Guard. You guys keep doing what you need to do. And let me know if you need anything from me. I’ll be at the HSCD in ten minutes.” With a click, the governor was gone.

“Is everyone else still there?” Kai said.

“I am,” Mary said, her voice quavering. “But George got off the phone to call his mother. She lives near the beach in Hilo.”

Kai looked at Brad, who shook his head. No word from Teresa.

“You should all take a minute to call your families,” Kai said. “Mary, you and George are too far away to do us any good right now, so I don’t want you to try to get back here.”

“Dammit!” Mary said. “Isn’t there anything we can do?”

“Eventually, we’ll have to leave the center and relocate somewhere up island. I’m thinking that Wheeler is the best option, so you can try heading in that direction. I don’t know how long cell phones will work, but keep them handy. Harry, since you’re already at the Maui Police Department, you can help coordinate there. All we can tell people is to get as far inland and as high up as possible.”

“Our houses will be hit by the first wave,” Harry said. Every person on the conference call would be homeless in a little less than an hour.

“I know. And we don’t have any time to get your personal stuff out. I’m sorry.” It was the same story for Kai. Fifteen years of his family’s memories would soon be lost forever.

“What about you guys?” Harry said, the concern in his voice apparent. “Don’t hang around there too long.”

“I will evacuate us in time to get to safety. But until then we have a job to do and very little time to do it. We’re going to have to throw our normal procedures out the window. At this point, all we can do is get as many people out of Honolulu as we can.”

The clock on the wall said 10:32.

“Fifty minutes,” Kai said. “That’s how long we’ve got to evacuate over half a million people.”

10:33 a.m.

49 Minutes to Wave Arrival Time

Kai called Rachel himself this time. He needed her to know how dangerous the situation was, especially because what he was telling her sounded so improbable. “It’s good you didn’t have Brad call me,” Rachel said. “I’d think it was a joke.”

“I know this sounds crazy, but it’s what the data are telling us.”

“An asteroid? I can’t believe it.”

“I know. But if I’m right, nobody is safe in that hotel.”

“What about the Starlight restaurant on the twenty-eighth floor? We’ve got lots of room up there.”

“Rachel, even if the wave doesn’t reach that high, the building might collapse.”

“But we have over a thousand guests staying in the hotel! Not to mention a ballroom full of disabled veterans.”

“You’ve got to start evacuating them now. Do you have any buses for them?”

“I had some scheduled to pick them up and take them to the cemetery for the ceremony this afternoon, but they’re not supposed to be here for another hour.”

“Look, it’s at least a fifteen-minute walk to a safe zone from there. That means you’ve only got about thirty minutes left to get everyone out.”

“That’s not enough time—”

“Rachel, the tsunami doesn’t care if it’s enough time. That’s when it’s going to get here, and anyone left in the hotel after that time won’t make it.”