Three Common Questions

Those not familiar with the behavior of high-pressure fluids sometimes raise three questions.

1. How could rock float on water? The crust did not float on water; water was trapped and sealed under the crust. (Water pressure and pillars supported the crust.) The crust was like a thin slab of rock resting on and covering an entire waterbed. As long as the water mattress does not rupture, the dense slab will rest on top of less-dense water. Unlike a waterbed’s seal, which is only a thin sheet of rubber, the chamber’s seal was compressed rock almost 10 miles thick. Pressures 5 miles or more below the earth’s surface are so great that the rock can deform like highly compressed, extremely stiff putty.¹⁵ So the slightest tension crack could not open from below.

2. Temperatures increase with depth inside the earth. Subterranean water about 10 miles below the earth’s surface would have been extremely hot. Wouldn’t all life on earth have been scalded if that water flooded the earth?  No. Today’s geothermal heat is a result of the flood. To understand why and to see why life was not scalded, one must first understand tidal pumping and supercritical water (SCW)—a very high-energy, explosive form of water that was discovered in 1822.⁴⁶

Tidal Pumping.⁴⁷ Tides in the subterranean water lifted and lowered the massive crust twice daily, stretching and compressing the pillars, thereby generating heat and raising temperatures in the subterranean water. As certain minerals dissolved, this hot, high-pressure water increasingly contained the ingredients for limestone (CaCO₃), salt (NaCl), and quartz (SiO₂). In a few chapters, you will see why, after the flood, this dissolved quartz petrified some wood and cemented flood sediments into sedimentary rocks.

SCW.  At a pressure of one atmosphere—about 1.01 bar or 14.7 psi (pounds per square inch)—water boils at a temperature slightly above 212°F (100°C). As pressure increases, the boiling point rises. At a pressure of 3,200 psi (220.6 bars) the boiling temperature is 705°F (374°C). Above this pressure-temperature combination, called the critical point, water is supercritical and cannot boil.

The initial pressure in the 10-mile-deep subterranean chamber was about 62,000 psi (4,270 bars)—far above the critical pressure. After about a century⁴⁷ of tidal pumping, the subterranean water exceeded the critical temperature, 705°F. As the temperature continued to increase, the pressure grew, the crust stretched and weakened, and the energy from tidal pumping increasingly ionized the water.⁴⁸

SCW can dissolve much more salt (NaCl) per unit volume than normal water—up to 840°F (450°C).  At higher temperatures, all salt precipitates out (out-salts).⁴⁹ In a few pages, this fact will show why so much salt is concentrated on the earth and how salt domes formed.

SCW consists of microscopic liquid droplets dispersed within very dense water vapor. The hot droplets cool primarily by surface evaporation,⁵⁰ and their rate of cooling is proportional to their total surface area. The smaller a droplet, the larger its surface area is relative to its volume, so more of its heat can be quickly transferred to its surroundings. The liquid in SCW has an area-to-volume ratio that is a trillion (1012) times greater than that of the flood water that covered the earth’s surface. Consequently, the liquid in SCW cools almost instantly if its pressure drops, because the myriad of shimmering liquid droplets, each surrounded by vapor, can simultaneously evaporate. A typical SCW droplet at 300 bars and 716°F (380°C) consists of 5–10 molecules. These droplets evaporate, break up, and reform continually.⁵¹

This explains how the escaping supercritical liquid transferred its energy into supercritical vapor. How did the vapor lose its energy and cool? Rapid expansion. A remarkable characteristic of supercritical fluids is that a small decrease in pressure produces a gigantic increase in volume—and cooling. So, as the SCW flowed toward the base of the rupture, its pressure dropped and the vapor portion expanded and cooled to an extreme extent. [See “Rocket Science” on page 525.] As it expanded, it pushed on the surrounding fluid (gas and liquid), giving all fluid downstream ever increasing kinetic energy.

Eventually, the horizontally flowing liquid-gas mixture began to flow upward through the rupture. As the fluid rose, its pressure dropped to almost zero in seconds, so the electrical energy of ionization was released. The 10,000-fold expansion was a weeks-long, focused explosion of indescribable magnitude, accelerating the mixture, including rocks and dirt, into the vacuum of space.⁵²

In summary, as the flood began, SCW jetted up through a globe-encircling rupture in the crust—as from a ruptured pressure cooker. This huge acceleration expanded the spacing between water molecules, allowing flash evaporation, sudden and extreme cooling, followed by even greater expansion, acceleration, and cooling. Therefore, most of the vast thermal, electrical, chemical, and surface energy⁵³ in the subterranean water ended up not as heat at the earth’s surface but as extreme kinetic energy in all the fountains of the great deep. As you will see, these velocities were high enough to launch rocks into outer space—the final dumping ground for most of the energy in the SCW.

3. What Happens as a Fluid Becomes Supercritical?

Key Experiments. In 1822, French Baron Cagniard de la Tour performed a key experiment.⁴⁶ A specific amount of liquid was sealed inside a strong glass tube. The meniscus (the boundary between the liquid below and the vapor above) was visible. As the tube was heated, some liquid evaporated. Therefore, the pressure inside the tube and the vapor’s lower density steadily increased, while the liquid’s higher density slowly decreased.  When the two densities became equal—at a specific temperature and pressure now called the critical point—the meniscus disappeared. Was the substance a liquid, a vapor, or something else? For almost two centuries, no one knew.⁵⁴

By 2005, the results of sophisticated experiments on supercritical water were published. That work by scientists in Germany, France, Sweden, the Netherlands, and the United States showed that both liquid and vapor were present. The liquid consisted of microscopic droplets dispersed—actually floating—throughout the dense vapor.⁵¹

A Thought Experiment. What follows is conjecture. To my knowledge, no one has described the microscopic behavior of supercritical fluids (SFs) as I will below, but based on the 2005 experiments, the physics now seems clear. If we could view the meniscus in microscopic detail as the temperature approached the critical point, I believe we would see the following:

The liquid below the meniscus becomes increasingly agitated and resembles a choppy lake on a windy day. The liquid and vapor are nearly in equilibrium, so about as many molecules evaporate from the liquid as enter the liquid from the vapor. At these very high temperatures, vapor molecules strike the liquid surface at a furious rate and splash droplets of liquid up into the dense vapor. As the vapor’s density approaches the liquid’s density, the droplets float in the vapor! This process continues until all the liquid below the meniscus is dispersed as tiny droplets in the vapor, so the meniscus suddenly disappears. The shimmering droplets, suspended in the vapor, are then bombarded from all directions by vapor molecules acting as bullets. When these “bullets” strike a droplet, they either fragment the droplet, stick to it, or bounce off the droplet.  Droplets quickly fragment, merge, or evaporate.⁵⁵

Would these microscopic droplets float to the top of the vapor? No, but let’s assume they did. It would mean that the vapor was denser than the liquid droplets. Vapor molecules would be closer to each other, on average, than liquid molecules. Therefore, vapor molecules would frequently bond with each other and become liquid droplets. The presence of liquid droplets throughout the supercritical vapor contradicts our assumption that all the liquid had floated to the top of the vapor. With a little thought, it should become clear that liquid droplets almost instantly form and disappear within the dense vapor. In the process, many molecules ionize.

As temperatures rise, the vapor molecules travel faster and fragment more droplets. The droplets become, on average, even smaller. They also collide and merge more frequently, so at each new temperature, an equilibrium is quickly reached between droplets forming and disappearing.

Energy is expended in fragmenting droplets, because work must be done in stretching and breaking molecular bonds in the liquid phase.  Most of the energy expended in fragmenting molecules becomes ionization (electrical) energy. If the pressure drops, electrical energy is recovered and surface energy is given up; the volume expands rapidly and enormously. The faster the pressure drops, the more explosive—and cooler—the expansion.

When the flood began, the pressure in the jetting SCW dropped in seconds from at least 62,000 psi (4,270 bars) to almost zero. The energy released was huge. Because the 46,000-mile-long fountains continued this release for several weeks, one should not think of it as a single explosion. Instead, the jetting water was a powerful, earth-size engine that launched considerable mass from earth.

Great Solubility. Today, SFs (usually water and carbon dioxide) are studied primarily because of their great dissolving power. In 1879, J. B. Hannay and J. Hogarth first demonstrated this. When they rapidly dropped the pressure in a SF, the dissolved material precipitated as “snow.”⁵⁶ Why was the solubility of SFs so great, and why did the solute precipitate so rapidly?

Supercritical liquid droplets impacting solids (like a dense spray of bullets, each not much larger than a gas molecule) will penetrate, break up, and dissolve more of the solids than pure liquids.⁵⁷ Also, as described above, the liquid droplets almost instantaneously form and evaporate. When they evaporate, the dissolved solids precipitate (out-salt) as sediments onto a floor.⁵⁸ When new droplets form from merging vapor molecules, they contain no solute and can then dissolve more of the solid they encounter. During the flood, the escaping subterranean waters swept most of these loose, precipitated sediments on the chamber floor up to the earth’s surface.

Therefore, supercritical fluids can dissolve large quantities of organic material and certain minerals.⁵⁹ If the pressure in the supercritical fluid suddenly drops, the liquid evaporates explosively and the solid precipitates as “snow.” Three common precipitates from the subterranean water were limestone (CaCO₃), salt (NaCl), and quartz (SiO₂).