Our planet, Earth, is the only place in the universe known to have liquid water.1 In fact, astronauts looking at Earth’s surface from outer space see mainly water. The ocean covers 71% of the total area, and contains enough water to cover the whole planet to a depth of 2.7 km (1.7 miles) if the surface were completely flat.
The ocean is essential for life on Earth, and also helps make the climate fairly moderate. However, although the ocean contains 1,370 million cubic kilometres (334 million cubic miles) of water, humans can’t survive by drinking from it—it is too salty.
To a chemist, ‘salt’ refers to a wide range of chemicals where a metal is combined with a non-metal. Ordinary common salt is a compound formed when the metal sodium combines with the non-metal chlorine—sodium chloride. This contains electrically charged atoms, called ions, that attract each other, resulting in a fairly hard crystal. When salt dissolves, these ions separate. Sodium and chloride ions are the main ions in seawater, but not the only ones. The salty seas benefit man, because the ocean provides many useful minerals for our industries.
How old is the sea?
Many processes (see below) bring salts into the sea, while they don’t leave the sea easily. So the saltiness is increasing steadily. Since we can work out how much salt there is in the sea, as well as the rates that salts go into and out of the sea, we should be able to calculate a maximum age for the sea.
In fact, this method was first proposed by Sir Isaac Newton’s colleague, Sir Edmond Halley (1656–1742), of comet fame.2 More recently, the geologist, physicist, and pioneer of radiation therapy, John Joly, (1857–1933) estimated that the oceans were 80–90 million years old at the most.3 But this was far too young for evolutionists, who believed that life evolved in the ocean billions of years ago.
More recently, the geologist Dr Steve Austin and the physicist Dr Russell Humphreys analyzed figures from secular geoscience sources for the quantity of sodium ion (Na+) in the ocean, and its input and output rates.4 The slower the input and faster the output, the older the ocean could be.
Every kilogram of seawater contains about 10.8 grams of dissolved Na+ (about 1% by weight). This means that there is a total of 1.47 x 1016 (14,700 million million) tonnes of Na+ in the ocean.
Water on the land can dissolve salt outcrops, and can weather many minerals, especially clays and feldspars, and leach the sodium out of them. This sodium can be carried into the ocean by rivers. Some salt is supplied by water through the ground directly to the sea—called submarine groundwater discharge (SGWD). Such water is often very concentrated in minerals. Ocean floor sediments release much sodium, as do hot springs on the ocean floor (hydrothermal vents). Volcanic dust also contributes some sodium.
Austin and Humphreys calculated that about 457 million tonnes of sodium now comes into the sea every year. The minimum possible rate in the past, even if the most generous assumptions are granted to evolutionists, is 356 million tonnes/year.
Actually, a more recent study shows that salt is entering the oceans even faster than Austin and Humphreys thought.5 Previously, the amount of SGWD was thought to be a small fraction (0.01–10%) of the water from surface runoff, mainly rivers. But this new study, measuring the radioactivity of radium in coastal water, shows that the amount of SGWD is as much as 40% of the river flow.6 This means that the maximum possible age of the ocean is even smaller.
People who live near the sea often have problems with rust in cars. This is due to salt spray—small droplets of seawater escape from the ocean, the water evaporates, leaving behind tiny salt crystals. This is a major process that removes sodium from the sea. Another major process is called ion exchange—clays can absorb sodium ions and exchange them for calcium ions, which are released into the ocean. Some sodium is lost from the ocean when water is trapped in pores in sediments on the ocean floor. Certain minerals with large cavities in their crystal structure, called zeolites, can absorb sodium from the ocean. [Ed. note: some anti-creationists have proposed that sodium is removed by albitization, but see addendum for Dr Humphreys’ response.]
However, the rate of all of this sodium output is far less than the input. Austin and Humphreys calculated that about 122 million tonnes of sodium leaves the sea every year. The maximum possible rate in the past, even if the most generous assumptions are granted to evolutionists, is 206 million tonnes/year.
Estimating the ocean’s age
Granting the most generous assumptions to evolutionists, Austin and Humphreys calculated that the ocean must be less than 62 million years old. It’s important to stress that this is not the actual age, but a maximum age. That is, this evidence is consistent with any age up to 62 million years, including the biblical age of about 6,000 years.
The Austin and Humphreys calculation assumes the lowest plausible input rates and fastest plausible output rates. Another assumption is that there was no dissolved salt to start with. If we assume more realistic conditions in the past, the calculated maximum age is much less.
For one thing, God probably created the oceans with some saltiness, so that saltwater fish could live comfortably in it. Noah’s Flood would have dissolved large amounts of sodium from land rocks. This would have found its way into the oceans when the Flood waters retreated. Finally, the larger-than-expected SGWD would further reduce the maximum age.
The salinity of the oceans is a strong evidence that they, and the Earth itself, are far younger than the billions of years required for evolution, and is consistent with the biblical age of about 6,000 years. It is also far younger than the evolutionists’ ‘dates’ for many marine creatures. In short, the sea is not salty enough to suit the taste of evolutionists! Of course, all such calculations depend on assumptions about the past, like the starting conditions and constant rates of processes. They can never prove the age of something. For that, we need an eye-witness (cf. Job 38:4). The point of such calculations is to demonstrate that even under the evolutionists’ own assumptions about the past, the Earth is far younger than is usually claimed and does not contradict the Bible.
One anti-creationist called Glenn Morton claims that the sodium-rich feldspar called albite (NaAlSi3O8) would form permanently on the ocean floor, taking sodium out of seawater. He claims that such a sodium sink would invalidate the age calculations of Drs Austin and Humphreys. But Dr Humphreys answered a critic who cited Glenn Morton and gave permission for his response to be reproduced below:
No, Glenn Morton is not at all correct on this, and sincere creationists can continue using sea sodium as an evidence for a young world. Morton showed you an early letter in his correspondence with Steve Austin and me, but not our replies. He also did not show you how he terminated the correspondence.
What happens is this: indeed albite forms in mid-ocean vents and takes sodium out of the high-temperature sea water. But then when the albite gets into cooler water, it decomposes into the mineral chlorite and releases the same amount of sodium back into the sea water. That is why albite (in any significant amounts) is found only at the mid-ocean ridges and nowhere else. So his “albite sink” would change into a “chlorite source”, and the net effect on sodium in the sea would be zero.
That may seem technical to you. So here is a non-technical way you can judge for yourself whether Morton is right or not: find out whether he has published his “albite sink” theory in a peer-reviewed secular geochemistry journal. The foremost one has the Latin title Geochimica et Cosmochimica Acta. Such journals would be overjoyed to publish his theory if it were correct, because it would solve the 75-year-old problem Steve and I pointed out, the great imbalance between ingoing and outgoing sodium. The secular science establishment would probably award Morton the Nobel Prize for it!
Moreover, Morton would be very proud to have his theory published in such a journal and would be sure to mention it prominently on his website. Let me know if you find such a citation there. If you don’t, then you know Morton is blowing smoke at you.
Smoke and mirrors are generally what you will get on skeptics’ and old-earther web sites. They shun peer review and publication. Instead they rely on the naïveté of most of their readers to protect their bad science from exposure. Anybody can say anything on a website, and they do. Psalm 1:1 promises a blessing for avoiding such company:
“How blessed is the man who does not walk in the counsel of the wicked, Nor stand in the path of sinners, Nor sit in the seat of scoffers!”