Boyd Morrison: The Tsunami Countdown

“Thanks for joining us this fine morning,” Reggie said. “I thought maybe you were gonna play hooky today.”

Kai nodded toward Reggie’s sandwich, which was already half its previous size. “Is there ever a time of day when you don’t eat?”

“Hey, I don’t want to get all skinny like you.”

There was no danger of that. Reggie Pona, a huge bear of a man who used to be a defensive lineman at Stanford, must have weighed at least three hundred pounds. Reggie was also one of the brightest geophysicists Kai had ever met. A Samoan by birth, he had used his college football scholarship to accomplish his true goal of becoming a scientist.

Reggie took a bite and continued to talk while he chewed. “I thought you might go with your friends to the beach. Teresa is hot, by the way.”

“You know, sometimes you almost convince me that you’re not a nerd,” Kai said. “But then you open your mouth to talk and remind me. Besides, I couldn’t leave you alone with all those impressionable sixth graders. You scared the bejesus out of the last group.”

“I was just telling it like it is.”

“But did you have to show those pictures from Sri Lanka? I think ten-year-olds are a little young to see photos of dead bodies.”

“Hey, if it keeps them from running down to the shore during the next tsunami warning, I’ve done my job.”

“Yeah, well, maybe I’ll do the next few tours. Where’s the bulletin?”

Reggie handed Kai a sheet of paper. On it was the date followed by a standard tsunami information message:

TSUNAMI BULLETIN NUMBER 001

PACIFIC TSUNAMI WARNING CENTER/NOAA/NWS

ISSUED AT 1858Z

THIS BULLETIN IS FOR ALL AREAS OF THE PACIFIC

BASIN EXCEPT

ALASKA—BRITISH COLUMBIA—WASHINGTON—

OREGON—CALIFORNIA.

… TSUNAMI INFORMATION BULLETIN …

THIS MESSAGE IS FOR INFORMATION ONLY.

THERE IS NO TSUNAMI WARNING.

OR WATCH IN EFFECT.

AN EARTHQUAKE HAS OCCURRED WITH THESE

PRELIMINARY PARAMETERS

ORIGIN TIME—1858Z

COORDINATES—7.1 NORTH 166.4 WEST

LOCATION—NORTHWEST OF CHRISTMAS ISLAND,

KIRIBATI ISLANDS

MAGNITUDE—6.6

EVALUATION

A DESTRUCTIVE TSUNAMI WAS NOT GENERATED

BASED ON EARTHQUAKE AND

HISTORICAL TSUNAMI DATA.

THIS WILL BE THE ONLY BULLETIN ISSUED FOR

THIS EVENT UNLESS ADDITIONAL INFORMATION

BECOMES AVAILABLE.

THE WEST COAST/ALASKA TSUNAMI WARNING

CENTER WILL ISSUE BULLETINS

FOR ALASKA—BRITISH COLUMBIA—

WASHINGTON—OREGON—CALIFORNIA.

Kai looked at Reggie. “It doesn’t seem like anything to be concerned about.”

Normally Kai would consult with Harry, but today Reggie and Kai were on their own. Although Kai was growing more comfortable with his responsibilities, he was still fairly new. This was the first bulletin issued while he was in charge.

The previous assistant director had left for NOAA headquarters in Washington to coordinate the development of a worldwide tsunami warning system. Kai’s position at NOAA’s Center for Tsunami Research put him on the short list of replacement candidates. From Kai’s perspective, the job had seemed perfect. He could move his career forward while still doing interesting research. Rachel had plenty of job opportunities at Honolulu hotels. And Kai could finally get out of Seattle’s rainy climate and back to warm, sunny Hawaii.

“No, it shouldn’t be anything to worry about,” said Reggie. “But it is pretty exciting.”

“Why?”

“I’ll get to that in a minute. But the threat of a tsunami is almost negligible because the event was not tsunamigenic.” The statement was made as a fact, not an opinion.

“You seem pretty confident.”

Reggie smiled. He always smiled when he was about to explain something that was perfectly obvious to him. “It barely triggered the alarms. The reading was just 6.6. A couple of ticks down, and we wouldn’t have even sent the bulletin.”

“Remember the Asia tsunami?” Kai said. “The initial readings on that were 8.0. It ended up being a 9.0.” Because the moment magnitude scale for earthquakes—a successor to the Richter scale—is nonlinear, the power of an earthquake goes up exponentially the higher it is on the scale: an earthquake measuring 9.0 releases over thirty times more energy than an 8.0 earthquake.

“I’m just checking with NEIC now, but I don’t see it going up much.” The seismic equipment at the National Earthquake Information Center monitored data readings from stations around the world, allowing them to determine the location of an earthquake to within a hundred meters.

“And,” Reggie continued, “the seismic wave patterns suggest a strike-slip event.” Strike-slip faults move sideways instead of vertically. Vertical displacements of the ocean floor cause most tsunamis, like the one that had struck South Asia in 2004.

“Besides, it’s in an area that has never generated a tsunami. That’s actually why I called you,” said Reggie. “Look at this.” He pointed at the computer monitor.

The screen showed a map of the central Pacific with a blue dot pinpointing a position five hundred miles northwest of Christmas Island, southwest of the Palmyra Atoll. The color blue meant that the quake was located near the earth’s surface.

“What’s the distance from here?”

“About two thousand kilometers,” said Reggie. A little more than twelve hundred miles.

Kai did the quick mental calculation in his head that was second nature to all tsunami scientists. Since all tsunamis traveled at approximately five hundred miles per hour in open ocean—about the speed of a jet airliner—it was easy math. But before Kai could speak, Reggie handed him a printout.

“Already got it.”

The printout showed a list of station names and codes of all of the tide gauges in the Pacific Ocean. Next to each station name was its latitude, longitude, and the estimated arrival time for the potential tsunami.

“Looks like that gives us between two and two and a half hours.”

“I’m predicting we’ll barely see a tide change,” said Reggie. “The tide sensor at Christmas Island will tell us for sure.”

Kai looked back at the printout. Any wave generated by the event would reach Christmas Island in thirty-five minutes.

He checked the tide gauge schedule. Most of the tide gauges would transmit their readings to a satellite, which then got relayed to the PTWC. Although the gauges were cheap to produce and monitored tide levels twenty-four hours a day, their main drawback was that they sent the tide-level data only once an hour.

Kai scanned the list to find Christmas Island. The next transmission would be only five minutes after the wave was supposed to arrive there.

“Show me the earthquake map.”

Reggie clicked on the appropriate icon, and colored dots bloomed on the map around the blue marker. The circles showed the seismic events around the Pacific Rim, with the different colors representing the depths of the events. A few red stars punctuated the map, showing where tsunamis had started. None of the stars was located within five hundred miles of the blue dot.

“That area has never even had an earthquake,” Kai said.

“Weird, huh?” Reggie said. “I’d guess one of two things.

First, it could be a fault that we’ve never detected before.”

“Highly unlikely.”

“Right. But second—and this is the exciting part—it could be a new seamount. That would explain why it’s so shallow.”

Now Kai understood Reggie’s excitement. A new seamount was a rare phenomenon, essentially the birth of a new island. An underwater volcano erupted over a magma hot spot on the ocean floor, building a mountain around itself and regularly unleashing earthquakes in the process. If the seamount got high enough, it broke through the surface of the water, which is exactly how the Hawaiian Islands were formed and were still forming, as the continual eruption of Kilauea on the Big Island spectacularly demonstrated.