In honor of WorldWaterDay, learn more about the mounting evidence that some 3 billion to 4 billion years ago, the planet’s oceans held nearly twice as much water—enough to submerge today’s continents above the peak of Mount Everest.
Across the ages, sea levels have risen and fallen with temperatures—but Earth's total surface water was always assumed to be constant. Now, evidence is mounting that some 3 billion to 4 billion years ago, the planet's oceans held nearly twice as much water—enough to submerge today's continents above the peak of Mount Everest. The flood could have primed the engine of plate tectonics and made it more difficult for life to start on land.
Two minerals found deep in the mantle store much of its water today: wadsleyite and ringwoodite, high-pressure variants of the volcanic mineral olivine. Rocks rich in those minerals make up 7% of the planet's mass, and although only 2% of their weight is water today,"a little bit adds up to a lot," says Steven Jacobsen, an experimental mineralogist at Northwestern University.
Work by Johnson and Boswell Wing, a geobiologist at the University of Colorado, Boulder, offers more evidence. Samples from a 3.24-billion-year-old chunk of oceanic crust left on Australia's mainland were far richer in a heavy oxygen isotope than the present-day oceans. Because water loses this heavy oxygen when rain reacts with the continental crust to form clays, its abundance in the ancient ocean suggests the continents had barely emerged by that point,study.
South Africa Latest News, South Africa Headlines
Similar News:You can also read news stories similar to this one that we have collected from other news sources.
Ukraine: How Tensions on Earth Have Invaded the Space WorldDespite NASA administrator Bill Nelson’s reassurances on Friday morning that his Russian counterpart Dmitry Rogozin’s recent statements about the United States—including the particularly catchy line that the United States will have to use broomsticks to get to space once Russia stops supplying U.S.-based companies with rocket engines—were just a bunch...
Read more »
Greater than 99% chance Earth will have a top ten warmest year on recordFebruary was relatively toasty for Earth. It's a good bet this will be one of the world's warmest years on record.
Read more »
People think they spotted a UFO submerged underwater on Google EarthSome people believe they may have discovered a submerged UFO off the coast of Peru, sitting at the bottom of the Pacific Ocean.
Read more »
How Could One of the World’s Favorite Jets Just Plunge to Earth Like a Ballistic Missile?Aviation experts are baffled by data showing that a China Eastern Boeing 737-800 about to begin its descent to the city of Guangzhou suddenly plunged vertically to earth like a missile, killing the 123 passengers and nine crew aboard.
Read more »
Ice Ages: What Causes the Earth to Freeze Over Every Few Million Years?At least five major ice ages have been documented in Earth's history. And guess what? You're living in an ice age right now. But don’t expect the planet to chill over from pole to pole.
Read more »
Man's Greatest Crimes Against the Earth, in PicturesHumans rule the world … and destroy it in the process.
Read more »