Shock Wave (Dirk Pitt 13)

"Hiram Yaeger, Admiral. Sorry to bother you."

"No need for apologies, Hiram. I know you wouldn't contact me outside the office if it wasn't urgent."

"Is it convenient for you to come to the data center?"

"Too important to tell me over the phone?"

"Yes, sir. Wireless communication has unwanted ears. Without sounding overdramatic, it is critical that I brief you in private."

"Rudi Gunn and I will be there in half an hour." Sandecker slipped the phone back into the pocket of his coat and resumed eating.

"Bad news?" asked Gunn.

"If I read between the lines correctly, Hiram has gathered new data on the acoustic plague. He wants to brief us at the data center."

"I hope the news is good."

"Not from the tone of his voice," Sandecker said soberly. "I suspect he discovered something none of us wants to know."

Yaeger was slouched in his chair, feet stretched out, contemplating the image on an oversized video display computer terminal when Sandecker and Gunn walked into his private office. He turned and greeted them without rising from his chair.

"What do you have for us?" Sandecker asked, not wasting words.

Yaeger straightened and nodded at the video screen. "I've arrived at a method for estimating convergence positions for the acoustic energy emanating from Dorsett's mining operations."

"Good work, Hiram," said Gunn, pulling up a chair and staring at the screen. "Have you determined where the next convergence will be?"

Yaeger nodded. "I have, but first, let me explain the process." He typed in a series of commands and then sat back. "The speed of sound through seawater varies with the temperatures of the sea and the hydrostatic pressure at different depths. The deeper you go and the heavier the column of water above, the faster sound travels. There are a hundred other variables I could go into, dealing with atmospheric conditions, seasonal differences, convergence-zone propagation access and the formation of sound caustics, but I'll keep it simple and illustrate my findings."

The image on the viewing screen displayed a chart of the Pacific Ocean, with four green lines, beginning at the locations of the Dorsett mines and intersecting at Seymour Island in the Antarctic. "I began by working backward to the source from the point where the acoustic plague struck. Tackling the hardest nut to crack, Seymour Island, because it actually sits around the tip of the Antarctic Peninsula in the Weddell Sea, which is part of the South Atlantic, I determined that deep ocean sound rays were reflected by the mountainous geology on the seafloor. This was kind of a fluke and didn't fit the normal pattern. Having established a method, I calculated the occurrence of a more elementary event, the one that killed the crew of the Mentawai."

"That was off Howland Island, almost dead center in the Pacific Ocean," commented Sandecker.

"Far simpler to compute than the Seymour convergence," said Yaeger as he typed in the data that altered the screen to show four blue lines beginning from Kunghit, Gladiator, Easter and the Komandorskie Islands and meeting off Howland Island. Then he added four additional lines in red. "The intersection of convergence zones that wiped out the Russian fishing fleet northeast of Hawaii," he explained.

"So where do you fix the next convergence-zone inter section?" asked Gunn.

"If conditions are stable for the next three days, the latest death spot should be about here."

The lines, this time in yellow, met nine hundred kilo meters south of Easter Island.

"Not much danger of it striking a passing ship in that part of the ocean," mused Sandecker. "Just to be on the safe side, I'll issue a warning for all ships to detour around the area."

Gunn moved in closer to the screen. "What is your degree of error?"

"Plus or minus twelve kilometers," answered Yaeger "And the circumference where death occurs?"

"We're looking at a diameter anywhere from forty to ninety kilometers, depending on the energy of the sound rays after traveling great distances."

"The numbers of sea creatures caught in such a large area must be enormous."

"How far in advance can you predict a convergence zone intersection?" Sandecker queried.

"Ocean conditions are tricky to predict as it is," replied Yaeger. "I can't guarantee a reasonably accurate projection beyond thirty days into the future. After that; it becomes a crapshoot."

"Have you calculated any other convergence sites beyond the next one?"

"Seventeen days from now." Yaeger glanced at a large calendar with a picture of a lovely girl in a tight skirt sitting at a computer. "February twenty-second."