Last year I published a blog post regarding young-Earth creationists’ use of seawater composition to “prove” that Earth is nowhere near 4.5 billion years old (Aluminum and the 100-year old oceans). This argument is one that needs to be added to their growing “Arguments creationists should not use” page, but it continues to make the rounds. This month’s Acts & Facts publication from the Institute for Creation Research has a rather inconsistent article called “The Ocean’s Salt Clock Shows a Young World,” written by ICR Senior Science Lecturer Frank Sherwin.
On the one hand, Sherwin argues that sodium inputs into the ocean far outweigh sodium outputs, proving that the age of Earth’s oceans cannot be anywhere near the billions of years as advocated by geologists. The most significant sodium input into seawater is ions dissolved in river water. Outputs—those processes that remove sodium from seawater—include sea spray and exchange of sodium ions with other ions in clay minerals on the sea floor. According to Sherwin, the maximum age for the oceans based on sodium concentration is 40-60 million years, and the oceans must be much younger than this because it would be best to assume that the oceans were created with a composition not all that different than what it is today.
On the other hand, Sherwin brushes off the criticism that similar reasoning using aluminum would show that the ocean is only 100 years old. He states that aluminum concentrations in the oceans are at equilibrium but sodium concentrations are not. Perhaps this is a case of “sodium concentrations support our position, and aluminum values do not, so the sodium values are valid and the aluminum ones are not.”
In reality, concentrations of all elements in seawater are somewhere near equilibrium, but none of them are perfectly at equilibrium at any one time. In other words, the amount of sodium in seawater—or of any other element—can increase or decrease over time as global conditions change. This has certainly been true in the Quaternary Period, with rapid and significant climate and sea level changes, and has likely been true throughout geologic history.
Sherwin concludes his article with:
“Accumulating salt in the ocean does not “prove” anything, but it does deal a death blow to evolutionary ideas. Holding to the well-attested biblical text gives us the true age of the world’s oceans–measured in just thousands of years.”
It is not clear what he means by “not proving anything,” because he clearly thinks he has proven something. But he hasn’t proven anything, as one can see by diving a little deeper into the literature. On a side note, many conservative Biblical scholars would contest the idea that the Bible requires an Earth that is only a few thousand years old.
A technical treatment of the issue from a young-Earth creationist perspective is The Sea’s Missing Salt: A Dilemma for Evolutionists, by Austin and Humphreys. They examine sodium inputs and outputs, and claim that 3.56 x1011 kg of sodium enters the ocean per year, while only 2.06 x1011 kg is removed. If this is true, sodium concentrations in the ocean are increasing over time rather than being near equilibrium.
Christian geophysicist Glenn Morton (formerly a young-Earth creationist) wrote a response to Austin and Humphreys’ article, closely examining their values for sodium inputs and outputs. Morton identified additional mechanisms for removal of sodium from seawater, and calculates that 3.81×1011 of sodium is removed from the ocean per year, which is greater than the amount of sodium that enters. There is a degree of uncertainty about the magnitude of some values, as many seafloor geochemical processes are only incompletely understood, but Morton’s values are likely to be at least approximately correct.
Conclusion: Ion concentrations—whether of sodium, aluminum, or any other element—cannot be used to determine the age of the oceans.
Or perhaps we should conclude from these numbers that the oceans have not been created yet!
Grace and Peace