The Arctic (Part Two)

"This is unlike any structure we've seen before." Marcus studied the data on the screen. "Norway and Finland had concentrated cavities, while Greenland had a chain-like network of nodes. This is a dispersed, continuous region. It's as if the entire seabed is vibrating slowly."

Harry pressed his palm against the railing again and felt for a while.

"The vibration is spread across the entire area, with no obvious center. Its frequency is extremely low and its cycle very long, like some movement of the crust itself. But the nested high-frequency component is artificial—a regular sequence of pulses. It's different from the Greenland network, more like an earlier form of encoding."

"Earlier?" Cassandra asked.

"The Greenland network uses a low-frequency carrier with high-frequency pulses. That's the style of the Norse settlers. The encoding here is simpler, with shorter pulse sequences and longer intervals, like a more primitive version." Harry withdrew his hand. "It may be older than the Norse settlers' network."

Cassandra turned to the appendix on the last page of the Nordic Ley Line Treatise and searched its brief notes on polar ley line activity. "This volume doesn't cover the North Pole, but it does mention ley line activity in the far north. It describes it as 'ancient and slow, like a moving glacier.' There's no more detail."

"Then we may need to check the original documents in the Confederation archives," Isabelle said.

That afternoon, the icebreaker remained near the signal source for several hours while Marcus collected continuous monitoring data.

Harry checked what he sensed from different positions and found that the vibration's frequency and amplitude were uniform throughout the area, with no clear direction or center.

He compiled his findings into a complete record and compared the structure with everything they had found before.

"This structure is different