A claim of vast reservoirs of water deep in the earth is based on indirect evidence, and likely has little or nothing to do with surface water or floods.
Science Daily reported, “New evidence for ‘oceans’ of water deep in Earth: Water bound in mantle rock alters view of Earth’s composition.” The amount of water may be triple the volume of all the earth’s oceans and lakes combined, the article says.
Researchers from Northwestern University and the University of New Mexico report evidence for potentially oceans worth of water deep beneath the United States. Though not in the familiar liquid form — the ingredients for water are bound up in rock deep in the Earth’s mantle — the discovery may represent the planet’s largest water reservoir.
The water is inferred to exist indirectly through echoes of seismic waves. Scientists believe it became entrapped in mantle rock during subduction of continental plates. The findings were published in Science Magazine.
A key point about this water is that it is bound up in mantle rock; it does not exist in a liquid form. Indeed, it cannot be liquid, because it is under extreme pressure and heat in the transition zone between the upper and lower mantle. Being 250 to 410 miles deep, it has no way to reach the surface and influence the oceans except through plate tectonics. The “ingredients” for water are bound up in minerals like ringwoodite and wadsleyite that can contain 1–3% water by weight.
A number of people sent links to this story as if it supported a global Flood. They must have pictured an ocean of liquid water under the crust, ready to burst forth. Unfortunately, this “water” is bound to minerals, like it is on the dry moon. Certain minerals can bind H2O in their chemical composition. Even though the sheer volume of the minerals could contain a sizeable quantity of water (if it were at normal surface temperature and pressure), that does not mean that this water is available to the surface.
It’s important not to read headlines and jump to conclusions. Headlines are often more flamboyant than the data. Unless a creation geologist can explain how the water could have become available to the surface in liquid form, it likely has nothing to do with a global flood. The article states that “water may be cycling between Earth’s surface and interior reservoirs through plate tectonics,” but the actual paper says nothing about this. In the evolutionary timeline such cycling would take millions of years. Creation geologists would have to present a plausible model for cycling it much faster. This water is much deeper than allowed in certain flood models such as the hydroplate theory, which postulates water chambers 10 miles beneath the crust. The mantle water is over 250 miles down. One needs to have a plausible mechanism for bringing it up from that depth and releasing it from its mineral cage if it is to play any role in surface conditions.
The deep “water” does create a problem for secular geologists and planetologists, though, because it increases the amount of volatile material that “Theia” (the hypothetical planet that smashed into earth and formed the moon—see 6/12/14) had to bring from elsewhere.
There are bodies in the solar system that do have oceans of liquid water under their surfaces: among them Europa, Enceladus, maybe Ganymede and Callisto, and now Pluto (Science Daily). Pluto may have had a subsurface liquid ocean in the past, the article says. The presence of liquid water in small bodies in the outer solar system poses a severe challenge for the belief these bodies are billions of years old.