Matthew rolled his eyes, clearly unimpressed by the concept. “Yeah, the seafloor beneath the Arctic, because the Earth is not a perfect sphere, its radius is about 16 miles smaller at the poles than at the equator.”
Sam grinned. “Hey, you were paying attention in school…”
“Sure I did, I’m just not interested in quizzes in an age when we have Google!”
Sam continued watching the bathymetric readout along the computer monitor. The system used a multibeam echosounder — AKA a really good sonar — to measure the topography of the ocean floor surrounding the trench.
The Mariana Trench is part of the Izu-Bonin-Mariana subduction system that forms the boundary between two tectonic plates. As the Pacific and Philippine plates converge, they carry seamounts — mountains on the ocean floor that don't reach the water's surface — and other underwater features with them toward the trench itself. Some of these plow into other structures on the opposite side of the trench in a sort of slow-motion seamount collision, or into the trench wall itself.
In this process, an underwater bridge forms, stretching across the Mariana Trench. So far, there have been four such bridges documented, some as high as 7000 feet above the trench and measuring 47 miles long.
After nearly forty-eight hours of tracking the grid search, the Tahila started to run low on diesel. As arranged earlier, they headed to the US Navy base on Guam to refuel. Boredom set in, and Sam started to read a new book on the top deck. It was a new one by one of his favorite authors, James D. Grant. He was about a third of the way through it when he headed downstairs to check their progress.
He entered the command center and stopped.
The echosounder had been left running and the bathymetric display still drifted across the monitor. The entire region was riddled with seamounts and guyots — flat-topped seamounts — but in front of him was a section of the Mariana Trench seafloor that was almost completely flat.
Sam’s eyes narrowed.
He pulled back the chair, and examined the image on the screen.
He turned to Matthew and shouted, “Full stop!”
Because in the middle of the near complete flatness, he spotted a large volcano — and next to that, a perfectly formed sphere.
Chapter Twenty-Nine
Sam gripped the hold bar next to the bathymetry station.
The Tahila’s quad HamiltonJet waterjets rotated their direction 180 degrees, slowing the vessel as though someone had just jammed on the brakes.
The Geiger Meter alarm went off, followed by the thermal alert. The area surrounding the sphere was filled with nuclear radiation which was releasing heat. Sam felt his heart pound in his chest. Someone had really done it. They had dumped nuclear waste at the bottom of the Mariana Trench. It might be years old, its toxic materials only being released to the surface after a recent eruption of a nearby submerged volcano.
When the Tahila came to a complete standstill in the water, Matthew stood next to Sam and stared at the bathymetric read out. Sam increased the frequency of the sonar bursts, upping the resolution of the image.
Matthew said, “Holy shit! What is that?”
“Beats the hell out of me. The thing looks like a sphere, partially buried in the seabed.” Sam’s lips twisted into a grin. “I don’t suppose you know what causes a natural sphere to form at the bottom of the sea?”
Matthew shook his head. “Strange underwater phenomena are meant to be your area of expertise.”
Sam stared at the monitor.
A sphere.
What the hell forms a perfect sphere in nature?
One of the most beautiful mathematical formations found in nature is the perfect sphere. A perfect sphere is defined as being completely symmetrical around its center, with all points on the surface lying the same distance from the center point. While Earth is often referred to as a sphere, it actually just misses this classification because it is slightly squashed at the poles. Nonetheless, perfect spheres do appear in nature and can be seen in examples such as bubbles, water drops, planets, and atoms. The sun itself is considered to be an almost perfect sphere.
But nothing should make a perfect sphere at the bottom of the ocean.
He took a screen capture of the strange spherical shape. The contours were derived by an array of sonar sound pings, meaning there was no way to physically see what it looked like.
But he could calculate how big it was by using a known height. He brought up the precise depth of the seafloor. 36,035 feet. Then, dragging the sonar icon to the very top of the sphere, he took a second reading. This one came back at 35, 035 feet, giving the sphere a diameter of 1000 feet and a radius of 500 feet.
Sam opened up the calculator app on the computer.
He applied the data to the formula — V = ⁴⁄₃πr³, and pressed enter.
He gasped as he saw the sphere’s volume:
523,598,775.5983 cubic feet.
He picked up the satellite phone and dialed the Secretary of Defense direct.
She picked up on the second ring. “What have you found, Mr. Reilly?”
Chapter Thirty
Sam and his crew spent the next eight hours trying to gather as much information as possible from the sphere. But there was only so much they could gather from the surface. To find out what it really was, they were going to need to go down there.
Matthew stepped beside Sam. “Our guests will be arriving any minute now if you want to meet them up on the deck, or do you want me to go?”
Sam stood up. “No. I’ll greet them. Thanks, Matthew.”
He climbed the series of steps up onto the top deck, next to the helipad.
His satellite phone rang as soon as he was outside.
It was Tom Bower.
“Tom. How did you go? Did you find the island of pumice?”
“No. It’s not here,” Tom replied. “I spoke with a local guide who took me to a nearby Moken flotilla. The guide said that the Moken are so well aligned with the sea, that they know if there’s a problem well before it starts.”
“And?”
“They say they’ve never seen a floating island before.”
“They’re certain?”
“Yeah. If they had, it would be the sort of news that everyone would have heard about.”
“That’s good to know,” Sam said. “It means we don’t need to be worried about clearing out the region to avoid a major catastrophe.”
“Any luck on your end?”
“We’ve found what we believe are the origins of the deadly pumice island. There’s a large volcanic mound in the base of the Mariana Trench. Submerged Geiger Counters indicate radiation levels are through the roof.”
“Wow. Someone really went through with it?”
“Dumping nuclear waste in the Mariana Trench?”
“Yeah.”
“It would appear so.”
Tom said, “We can organize a flight to Guam tonight, and help with the dive in forty-eight hours.”
“That’s all right, finish your vacation. I wouldn’t want to cut Genevieve short on what’s owed to the two of you.”
“Are you sure?”
Sam said, “Yeah. The Pentagon is sending me a nuclear expert and some other witness who wants a firsthand visual. So the Trident submarine won’t have room for a second pilot.”
“You’re sure?”
“Yeah. Go, have fun.”
Sam hung up.
In the distance, he heard the whir of a Eurocopter UH-72 Lakota. Sam watched it approach. He took a step back, waiting for it to alight. The pilot landed with the speed and precision expected of Navy aviators. The rotor blades kept turning, while two people climbed out, and with ducked heads, came to meet him.