Free Republic

The rotation of the Earth's inner core may be reversing, scientists have found in a study that sheds new light on geological processes occurring deep within our planet. The results of the research, published in the journal Nature Geoscience, indicate that changes in the rotation of the inner core could take place on a scale of decades. The study's authors told Newsweek the findings have implications for our understanding of how the core influences the other layers of the Earth.... ...these changes are likely part of an oscillation that takes place over roughly seven decades, with a previous turning point...

As our living ark swings around the Sun, its current loop is fairly circular. But Earth's orbit isn't as stable as you may think. Every 405,000 years, our planet's orbit stretches out and becomes 5 percent elliptical, before returning to a more even path.... ... Beaufort and team suggest the lag seen between orbital eccentricity and changes in climate could hint that "coccolithophores may drive – rather than just respond to – carbon cycle changes." In other words, these minuscule little organisms, along with other phytoplankton, may help change Earth's climate in response to these orbital events....

Earth's atmosphere is rising because of climate change, a new study shows. Weather balloon measurements, taken in the Northern Hemisphere over the past 40 years, reveal that the lowest layer of Earth's atmosphere — called the troposphere — has been expanding upward at a rate of roughly 164 feet (50 meters) per decade, and climate change is the cause, according to findings published Nov.r 5 in the journal Science Advances. ... ...Climate change isn't the only human-made driver of the rising tropopause. The stratosphere — the layer above the troposphere — is also shrinking....

If you'd been able to stare at Earth from space during the late Cretaceous, when Tyrannosaurus rex and Triceratops roamed, it would've looked like the whole planet had tipped over on its side. According to a new study, Earth tilted by 12 degrees about 84 million years ago.... The researchers found that, between 86 and 79 million years ago, the crust and mantle had rotated around Earth's outer core and back again — causing the entire planet to tilt and then right itself like a roly-poly toy.... ...Prior to the late Cretaceous, the Pacific Plate — the largest tectonic plate...

Full title: Ancient bubbles in Australian rocks show early Earth's air weighed less than half today's atmosphere Air bubbles trapped in 2.7 billion-year-old Australian rock suggest the Earth's atmosphere weighed less than half of today and was much thinner than previously thought. Researchers analysed the size of air bubbles that formed at the top and bottom of lava flows along the Beasley River in Western Australia's Pilbara region almost three billion years ago and used the data to calculate the atmospheric pressure at the time. The results suggest that the air at the time exerted at most half the pressure...

Enlarge Image Thanks, California! Massive amounts of irrigation in California's Central Valley boost summer precipitation across the American Southwest and during that period increases runoff into the Colorado River, which flows through the Grand Canyon, by an average of 28%, a new study suggests. Credit: iStockphoto/Thinkstock Water diverted to central California's farmlands boosts rainfall in nearby states and may even exacerbate periodic flooding in some regions, a new study suggests. The phenomenon may also be happening elsewhere in the world. California's Central Valley—an area almost twice the size of Massachusetts where farmers raise more than 200 different crops, including...

From the American Geophysical Union weekly highlights:Key Points Minimum 23-24 showed recurrence intervals of 9.0 and 6.7-dHistorical geomagnetic activity data show that minimum 23-24 was unusualThe heliosphere during minimum 23-24 had unusual sectorial structure Since the mid-1800s, scientists have been systematically measuring changes in the Earth’s magnetic field and the occurrence of geomagnetic activity. Such long- term investigation has uncovered a number of cyclical changes, including a signal associated with 27-day solar rotation. This is most clearly seen during the declining phase and minimum of each 11-year solar cycle, when the Sun’s magnetic dipole is sometimes tilted with respect to...

The New Theory: Earth’s magnetic field is not produced by an internal dynamo within the planet. The magnetic field and the planet are separate parts of a complex dynamo system surrounding the planet. The system includes the planet, the magnetic field, radiation belts, and ring current. The same is true of the other planets. Saturn, Jupiter, Neptune, and Uranus are visible components of otherwise invisible planetary dynamo systems, which are all housed within a magnetosphere. According to this new theory, there is no internal dynamo within the planet. Planet Earth does not have a unique way of producing it’s magnetic...

CORVALLIS, Ore. – A team of scientists from Oregon State University has created the first global three-dimensional map of electrical conductivity in the Earth's mantle and their model suggests that that enhanced conductivity in certain areas of the mantle may signal the presence of water. What is most notable, the scientists say, is those areas of high conductivity coincide with subduction zones – where tectonic plates are being subducted beneath the Earth's crust. Subducting plates are comparatively colder than surrounding mantle materials and thus should be less conductive. The answer, the researchers suggest, may be that conductivity in those areas...

Science Daily — Although the discrepancy is not large, it is significant: Geodesists from the University of Bonn have remeasured the size of the Earth in a long lasting international cooperation project. The blue planet is accordingly some millimeters smaller than up to now assumed. The results are important, for example, to be able to demonstrate a climate contingent rise in sea level. View of the Earth as seen by the Apollo 17 crew traveling toward the moon. (Credit: Image courtesy of NASA/Johnson Space Center) The system of measurement used by the Bonn Geodesists is invisible. It consists of radiowaves...

When students sign up for college courses, they are not only responding to the catalogue course description. They know that the background and expertise of the instructor plays a part in the educational experience. It may be true that, as Penn State President Graham Spanier told the Philadelphia Inquirer, “There’s no national test that Penn State Students could take that’s going to help us educate them better or make us more accountable.” Nonetheless, professors nationwide have said some very revealing things, and if you take a class schedule, broken down by departments or subjects, and insert them accordingly, you get...

As the earth turns, the center of the earth turns even faster. Confirming assertions first made in 1996, a team of geophysicists are presenting data in the journal Science today showing that the earth's inner core, a ball of solid iron larger than the moon, spins faster than the rest of the planet. Over a period of 700 to 1,200 years, the inner core appears to make one full extra spin. That extra spin could give scientists information about how the earth generates its magnetic field. The inner core, 1,500 miles wide, sits at the center of the planet, ensconced...

WASHINGTON - The Earth became a major planetary body much earlier than previously believed, just 10 million years after the birth of the sun, researchers say. Experts now believe that the inner solar system planets — Mercury, Venus, Earth and Mars — actually began forming within 10,000 years after the nuclear fires of the sun were ignited about 4.5 billion years ago, says Stein B. Jacobsen, author of an analysis appearing Friday in the journal Science. Early in its life, the sun was surrounded by clouds of dust and gas. This material slowly clumped together into larger and larger pieces....

Last Updated: Thursday, 27 March, 2003, 12:02 GMT Is the Earth preparing to flip? By Dr David Whitehouse BBC News Online science editor Finding the shifting magnetic pole It is not just the plot for a far-fetched science-fiction disaster movie. Something unexplained really is happening to the Earth's magnetic field. In recent years, the field has been behaving in ways not previously seen in the admittedly short time it has been monitored. Some researchers think it may presage a geomagnetic reversal when the north and south magnetic poles flip. Such speculation takes place as the science-fiction movie The Core goes...

Link post: Geology Picture of the Week, June 9-15, 2002