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Leaking Earth could run dry
BBC
Wednesday, September 8, 1999
Researchers from the Tokyo Institute of Technology have calculated that about 1.12 billion tonnes of water leaks into the Earth each year. Although a lot of water also moves in the other direction, not enough comes to the surface to balance what is lost. Eventually, lead researcher Shigenori Maruyama and his colleagues believe, all of it will disappear... His figures, which he describes as conservative, suggest the leakage has caused sea levels to drop by around 600 metres in the last 750 million years. This trend has been largely obscured in the geological record by shorter-term variations in sea levels.
Remains of an ancient ocean
by Paul Cooper
26 August 1999
Until 65 million years ago, a great ocean, the Tethys, separated India from Asia. There were no Himalayas and no Tibetan Plateau... A team led by Rob Van der Voo of the Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan has found signs of this ancient ocean deep beneath the Indian subcontinent... By reconstructing the paths taken by earthquake waves through the Earth, they have created a three-dimensional computer model of the interior of the Earth beneath India and the surrounding area.
Earth's Interior May Contain Oceans Of Water, Geologist Says
ScienceDaily
December 17, 1997
As a rule, rocks on earth are quite dry -- much drier than meteorites, for example, which also contain wadsleyite. Earth rocks generally contain only a small fraction of 1 percent of water. Wadsleyite is about 3.3 percent water. That may not seem like much, but given the amount of wadsleyite scientists think is in the earth-- it could be three to five times the amount of all the surface water on the planet, Smyth said. "It's possible the earth has this way of regulating the amount of water on the surface," Smyth said... The earth's oceans have existed for at least four billion years, and have been fairly constant in volume over the last 500 million years. These "inner oceans" may play a role in regulating that supply, Smyth said. In 1996 Smyth also discovered wadsleyite II, which may store water under even greater pressures at a lower portion of the transition zone.
Earth could hold more water
by Philip Ball
8 March 2002
There is already thought to be several oceans' worth of water slightly higher in the mantle, at a depth of around 400-650 km. This region is called the transition zone, as it is between the upper and the lower mantle. The lower mantle's minerals can retain about a tenth as much water as the rocks above, Murakami's team finds. But because the volume of the lower mantle is much greater than that of the transition zone, it could hold a comparable amount of water... Any hydrogen in the rocks presumably comes from trapped water, an idea that other measurements support. The researchers found more hydrogen than previous experiments had led them to expect.
Inner Earth May Hold More Water Than the Seas
by Ben Harder
March 7, 2002
Based on what they witnessed in their lab, the researchers concluded that more water probably exists deep within the Earth than is present on Earth's surface -- as much as five times more... Murakami and his colleagues reached their conclusion based on how much water they managed to dissolve under the experiment's extreme conditions in several types of material that make up much of the lower mantle. They used heat and pressure -- 25.5 gigapascals of it, or more than 250,000 times natural atmospheric pressure at sea level -- to create four mineral compounds that exist in the lower mantle... Earth's oceans make up just 0.02 percent of the planet's total mass. T his means the vast lower mantle could contain many times more water than floats on the planet's surface.
New Evidence Suggests Early Oceans Bereft Of Oxygen For Eons
ScienceDaily LLC
March 5, 2004
Working with coauthor Timothy Lyons of the University of Missouri, the Rochester team examined samples from the modern seafloor, including the rare locations that are oxygen-poor today. They learned that the chemical behavior of molybdenum's isotopes in sediments is different depending on the amount of oxygen in the overlying waters. As a result, the chemistry of molybdenum isotopes in the global oceans depends on how much seawater is oxygen-poor. They also found that the molybdenum in certain kinds of rocks records this information about ancient oceans. Compared to modern samples, measurements of the molybdenum chemistry in the rocks from Australia point to oceans with much less oxygen.
Did comets water Earth?
University of Iowa news release
March 5, 2001
Frank reports that he obtained pictures of nine small comets among 1,500 images made between October 1998 and May 1999 using the Iowa Robotic Observatory (IRO) located near Sonoita, Ariz. In addition, he says that the possibility of the images being due to "noise," or electronic interference, on the telescope's video screens was eliminated by operating the telescope in such a manner as to ensure that real objects were recorded in the images. This operation of the telescope utilized two simple exposure modes for the acquisition of the images. One scheme used the telescope's shutter to provide two trails of the same small comet in a single image, and the second scheme used the same shutter to yield three trails in an image.

"In the two-trail mode for the telescope's camera, no events were seen with three trails, and for the three-trail mode, no events were seen with two trails," he says. "This simple shutter operation for the telescope's camera provides full assurance that real extraterrestrial objects are being detected."
Did Comets Flood Earth's Oceans?
European Space Agency
June 18, 2004
The Ptolemy experiment on Rosetta may just find out... It is a miniature laboratory designed to analyse the precise types of atoms that make up familiar molecules like water. Atoms can come in slightly different types, known as isotopes. Each isotope behaves almost identically in a chemical sense but has a slightly different weight because of extra neutrons in its nucleii... By analysing with Ptolemy the mix of isotopes found in Comet 67P/Churyumov-Gerasimenko, he hopes to say whether comet water is similar to that found in Earth's oceans. Recent results from the ground-based observation of another comet, called LINEAR, suggested that they probably are the same... However, if the comets are not responsible for Earth's oceans, then planetary scientists and geophysicists will have to look elsewhere... If comets did not supply Earth's oceans then it implies something amazing about the comets themselves. If Ptolemy finds that they are made of extremely different isotopes, it means that they may not have formed in our Solar System at all.
When The Earth Dried Out
Science Daily
February 11, 2002
About a billion years ago, the continents emerged relatively suddenly from an ocean that covered 95 percent of the Earth's surface, according to a new theory by Eldridge Moores, a geologist at the University of California, Davis. The appearance of large masses of dry land would have caused more extreme weather, changes in ocean currents and the emergence of proper seasons. In turn, these environmental changes may have led to rise in atmospheric oxygen that enabled the explosion of new life forms around 500 million years ago... In the early Earth, the ocean crust and the continental crust were much closer together in thickness, Moores said. That means that the difference between the height of the ocean floor and the height of the continents was much less. The oceans would have been much shallower, and the water would therefore have spread much further across the continents -- covering 90 to 95 percent of the planet's surface, instead of the present 70 percent. Many geologists agree with this scenario, Moores said. What is controversial is how quickly the Earth changed from a planet covered in water with a few mountainous islands to one with large continental landmasses. According to Moores' theory, the continents emerged quite suddenly, over about 200 million years... also implies that over time, the way plate tectonics works has changed.