Isaac's Storm - Erik Larson [36]
Six weeks after the second Indianola storm, a group of thirty prominent Galveston residents calling themselves the Progressive Association met and resolved to build a seawall. This was the same group that led the fight for federal money to turn Galveston into a deep-water port. The city’s engineer, E. M. Hartrick, went so far as to draft plans for the wall. He proposed “a dike ten feet high extending completely around the island, except for the north side. There, the wharves were to be raised to form the dike.” The city’s Evening Tribune endorsed the plan. “When men such as these say that work on seawall protection should be commenced at once and pushed to completion, the public can depend upon it that something tangible will be done—and that without unnecessary delay.”
The state eventually did authorize a bond to pay for the work. “But,” engineer Hartrick wrote, “this was some months after the flood, and by then the attitude was, Oh, we’ll never get another one—and they didn’t build.”
If Galveston had any lingering anxiety about its failure to erect a seawall, Isaac’s 1891 article would have eased them. It was here that he belittled hurricane fears as the artifacts of “an absurd delusion.” He was especially confident about storm surges. Galveston would escape harm, he argued, because the incoming water would spread first over the vast lowlands behind Galveston, on the Texas mainland north of the bay where the land was even closer to sea level.
“It would be impossible,” he wrote, “for any cyclone to create a storm wave which could materially injure the city.”
PART II
The Serpent’s Coil
THE STORM
Spiderwebs and Ice
THE STORM ENTERED the Caribbean Sea early on Friday morning, August 31, in a confetti of sparks and thunder, with increased winds that raised from the sea patches of dense foam and streaks of spindrift. In the cloudlight of morning the sea was a dead gray scabbed with green. Rain began falling on St. Kitts, an island west by northwest of Antigua. What made this rain unusual was the fact it did not deplete the clouds overhead. The storm only got bigger.
As vapor rose through the clouds and began to condense, it deposited its moisture on tiny bits of airborne debris, ranging from submicroscopic “Aitken” nuclei to pollen, spiderwebs, volcanic ash, steamship exhaust, Saharan dust, even the pulverized ferrous salts of meteors disintegrated in the atmosphere. Somewhere over St. Kitts, a giant plume of water, ice, and aerosol debris rocketed through the troposphere getting colder and colder until it penetrated the stratosphere, where it entered a realm of new warmth caused by direct radiation from the sun. Suddenly the plume was colder than the air around it. It lost buoyancy. It arced against the hard blue of the stratosphere and fell back toward the earth.
This descending air met air still rising from below. Falling droplets met ascending droplets. The collisions formed bigger drops and the bigger they grew, the faster they fell. Now they overtook other falling droplets and grew bigger still. A raindrop four-hundredths of an inch in diameter falls at nine miles an hour; a droplet six times as large falls at twenty. Billions of droplets now got bigger and bigger until they achieved terminal velocities capable of propelling them all the way to the ground.
Under ordinary circumstances, the process of rain production depletes clouds. The “sink rate,” or the rate at which water leaves a cloud, exceeds the supply of moisture arriving from the air and sea below, causing clouds to dissipate like ghosts returning to the afterworld. But hurricanes defeat this cycle. They use wind to harvest moisture and deliver it to their centers. As the wind races along the surface of the sea, it increases the rate of evaporation and captures spindrift and foam. The faster the wind blows, the more vapor it picks up and the more energy it transfers to the storm. The resulting surge of condensation and heat in the storm’s core causes even greater volumes of air to rush into the sky. Pressure falls again. Wind velocities