THE WAVE: A John Decker Thriller by J.G. Sandom Read Free Book Online Page A

understood. Generation and inundation are much more difficult to model.
    “Generation,” she explained, “is the process through which a seafloor disturbance – such as a movement along a fault – reshapes the surface of the sea. When nearly all of an earthquake's energy is released in a thrust motion, as in the Sumatra quake, a large tsunami is generated. In contrast, strike-slip earthquakes, such as the one in San Francisco in 1906, are not efficient tsunami generators.
    “The location of the 2004 Sumatra centroid,” she continued, “defined as the location of the center of energy release, was near the Sunda trench, in relatively deep water. This generally results in an initial tsunami with larger potential energy than a tsunami whose centroid is closer to shore. Researchers use an idealized model of a quake since only the orientation of the assumed fault plane and the quake’s location, magnitude and depth can be interpreted from seismic data. Other parameters, including the amount of slip, and its length and width, must be estimated. That’s why initial simulations frequently underestimate inundation, sometimes by a factor of five or ten.”
    The second screen sparkled with numbers, spinning formulae and colorful input fields; the third with animated models of tsunamis based on the various data feeds.
    “The second process,” she continued, “propagation, transports seismic energy away from the earthquake through undulations of the water. Waves slow down as they travel over decreasing water depth, so that they eventually overtake one another, narrowing the distance between them in a process called shoaling.”
    All three screens began to display clips of different tsunami landfalls, crashing through villages and towns, in color and black-and-white, rushing up rivers and canals, sweeping the world away.
    “Inundation,” she concluded, “the third and final stage, is the most difficult to model. The wave height is now so large that initial linear theory fails to describe the complicated interaction between the water and the shoreline. Vertical run-up can reach tens of meters, but it typically takes only two to three meters to cause significant damage. The Indian Ocean tsunami was responsible for killing more than two hundred thousand people worldwide – from Sumatra to Somalia – although some speculate the death toll may climb higher, to as many as a quarter of a million souls.”
    Scenes of devastation flickered behind her: flooded fields and leveled homes; the one-legged silhouette of Vidu.
    “The U.S. Geological Survey has identified sand and gravel deposits carried inland a great distance by inundation . . . ”
    As Swenson lectured, she drifted, thinking about her own past. Once, she too had been as fresh-faced and scrubbed and open to the world as these young students, when she’d first heard Dr. White speak at that lecture in Los Angeles. She had been at USC then, after her escape from South Dakota.
    Born in a small town called Chance to Eric Swenson, a geologist, and Dolly Aalborg, part-time clerk, Emily had been precociously intelligent from the very start, skipping two grades by the time she was but ten. At twelve, she had lost her mother to lung cancer. Soon, she was working after school in the same tourist shop her mother used to manage, selling turquoise and fake Native American nick-knacks to tourists on their way to and from the Badlands. Only her swimming had kept her sane. She’d been captain of the local high school swim team, and an accomplished diver, winning a state championship at sixteen. The following year she had been accepted to USC on a scholarship where she had majored in oceanography, with a minor in geology – just like her father, with whom she was still close. On the weekends she’d worked at a local dive shop, and this too became a lifelong passion. But, even then, her beauty had worked against her.
    Tall, voluptuous and blond, with robin-egg-blue eyes, few could